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Sound stops after ~3 seconds when playing AoE II HD #1

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heikomat opened this issue Jul 12, 2018 · 6 comments
Open

Sound stops after ~3 seconds when playing AoE II HD #1

heikomat opened this issue Jul 12, 2018 · 6 comments
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bug Something isn't working

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@heikomat
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When playing AoE II HD edition via playonlinux, the sound initially works, but after about 3 seconds in the main menu, it stops until the game is restarted.

Tested on Debian testing

@heikomat heikomat added the bug Something isn't working label Jul 12, 2018
@heikomat heikomat self-assigned this Jul 12, 2018
@heikomat
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heikomat commented Jul 13, 2018

Disabling suspend-on-idle as described here fixes the problem :)

Will add this to the e200ha-sound-manual and probably the automated setup script

@heikomat
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This fix seems to cause pulseaudio to utilize a whole core all of the time. needs further investigation

@ThisIsSet-L
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ThisIsSet-L commented Jul 14, 2018

Check the Pulse Audio log to make sure it isn't hammering the HDMI audio outputs. Mine went nuts when I applied the pulse audio config files, and I had to unload the HDMI sound card module.

Edit:I'll try to be more specific in a bit, I just woke up.

@heikomat
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@ThisIsSet-L thanks for the hint! it seems to indeed be the HDMI audio output. When enabling debug logs, my syslog is spammed with these lines over and over:

Jul 14 12:46:55 heiko-e200ha pulseaudio[1772]: I: [alsa-sink-HdmiLpeAudio] alsa-sink.c: Starting playback.
Jul 14 12:46:55 heiko-e200ha pulseaudio[1772]: D: [alsa-sink-HdmiLpeAudio] alsa-util.c: Got POLLERR from ALSA
Jul 14 12:46:55 heiko-e200ha pulseaudio[1772]: D: [alsa-sink-HdmiLpeAudio] alsa-util.c: Got POLLOUT from ALSA
Jul 14 12:46:55 heiko-e200ha pulseaudio[1772]: D: [alsa-sink-HdmiLpeAudio] alsa-util.c: PCM state is XRUN

@heikomat
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heikomat commented Jul 14, 2018

listing the sinkns with pactl list sinks and unloading the owner-module of the HDMI sink as described here did stop the syslog spamming and fixed the cpu usage, but i'm sure that now my hdmi audio is no longer working.

It's a step forward, but maybe we can find a way to make HDMI sound work without the insane cpu usage, and without the builtin audio being wrongfully suspended :)

@ThisIsSet-L
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This issue was seen on the patched 4.17 kernel I was using under Arch. And yes, I did the same thing to stop the same problem. It's a very narrow issue that I haven't been able to find anywhere else. Glad to know it wasn't entirely my fault.

heikomat pushed a commit that referenced this issue Aug 22, 2018
If usb_ep_autoconfig() fails (i.e. returns a null endpoint descriptor),
we expect afunc_bind() to fail (i.e. return a negative error code).

However, due to v4.10-rc1 commit f1d3861 ("usb: gadget: f_uac2: fix
error handling at afunc_bind"), afunc_bind() returns zero, telling the
caller that it succeeded. This then generates NULL pointer dereference
in below scenario on Rcar H3-ES20-Salvator-X target:

rcar-gen3:/home/root# modprobe g_audio
[  626.521155] g_audio gadget: afunc_bind:565 Error!
[  626.526319] g_audio gadget: Linux USB Audio Gadget, version: Feb 2, 2012
[  626.533405] g_audio gadget: g_audio ready
rcar-gen3:/home/root#
rcar-gen3:/home/root# modprobe -r g_audio
[  728.256707] ==================================================================
[  728.264293] BUG: KASAN: null-ptr-deref in u_audio_stop_capture+0x70/0x268 [u_audio]
[  728.272244] Read of size 8 at addr 00000000000000a0 by task modprobe/2545
[  728.279309]
[  728.280849] CPU: 0 PID: 2545 Comm: modprobe Tainted: G        WC      4.14.47+ torvalds#152
[  728.288778] Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
[  728.296454] Call trace:
[  728.299151] [<ffff2000080925ac>] dump_backtrace+0x0/0x364
[  728.304808] [<ffff200008092924>] show_stack+0x14/0x1c
[  728.310081] [<ffff200008f8d5cc>] dump_stack+0x108/0x174
[  728.315522] [<ffff2000083c77c8>] kasan_report+0x1fc/0x354
[  728.321134] [<ffff2000083c611c>] __asan_load8+0x24/0x94
[  728.326600] [<ffff2000021e1618>] u_audio_stop_capture+0x70/0x268 [u_audio]
[  728.333735] [<ffff2000021f8b7c>] afunc_disable+0x44/0x60 [usb_f_uac2]
[  728.340503] [<ffff20000218177c>] usb_remove_function+0x9c/0x210 [libcomposite]
[  728.348060] [<ffff200002183320>] remove_config.isra.2+0x1d8/0x218 [libcomposite]
[  728.355788] [<ffff200002186c54>] __composite_unbind+0x104/0x1f8 [libcomposite]
[  728.363339] [<ffff200002186d58>] composite_unbind+0x10/0x18 [libcomposite]
[  728.370536] [<ffff20000152f158>] usb_gadget_remove_driver+0xc0/0x170 [udc_core]
[  728.378172] [<ffff20000153154c>] usb_gadget_unregister_driver+0x1cc/0x258 [udc_core]
[  728.386274] [<ffff200002180de8>] usb_composite_unregister+0x10/0x18 [libcomposite]
[  728.394116] [<ffff2000021d035c>] audio_driver_exit+0x14/0x28 [g_audio]
[  728.400878] [<ffff200008213ed4>] SyS_delete_module+0x288/0x32c
[  728.406935] Exception stack(0xffff8006cf6c7ec0 to 0xffff8006cf6c8000)
[  728.413624] 7ec0: 0000000006136428 0000000000000800 0000000000000000 0000ffffd706efe8
[  728.421718] 7ee0: 0000ffffd706efe9 000000000000000a 1999999999999999 0000000000000000
[  728.429792] 7f00: 000000000000006a 000000000042c078 0000000000000000 0000000000000005
[  728.437870] 7f20: 0000000000000000 0000000000000000 0000000000000004 0000000000000000
[  728.445952] 7f40: 000000000042bfc8 0000ffffbc7c8f40 0000000000000000 00000000061363c0
[  728.454035] 7f60: 0000000006136428 0000000000000000 0000000000000000 0000000006136428
[  728.462114] 7f80: 000000000042c000 0000ffffd7071448 000000000042c000 0000000000000000
[  728.470190] 7fa0: 00000000061350c0 0000ffffd7070010 000000000041129c 0000ffffd7070010
[  728.478281] 7fc0: 0000ffffbc7c8f48 0000000060000000 0000000006136428 000000000000006a
[  728.486351] 7fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[  728.494434] [<ffff200008084780>] el0_svc_naked+0x34/0x38
[  728.499957] ==================================================================
[  728.507801] Unable to handle kernel NULL pointer dereference at virtual address 000000a0
[  728.517742] Mem abort info:
[  728.520993]   Exception class = DABT (current EL), IL = 32 bits
[  728.527375]   SET = 0, FnV = 0
[  728.530731]   EA = 0, S1PTW = 0
[  728.534361] Data abort info:
[  728.537650]   ISV = 0, ISS = 0x00000006
[  728.541863]   CM = 0, WnR = 0
[  728.545167] user pgtable: 4k pages, 48-bit VAs, pgd = ffff8006c6100000
[  728.552156] [00000000000000a0] *pgd=0000000716a8d003
[  728.557519] , *pud=00000007116fc003
[  728.561259] , *pmd=0000000000000000
[  728.564985] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[  728.570815] Modules linked in:
[  728.574023]  usb_f_uac2
[  728.576560]  u_audio
[  728.578827]  g_audio(-)
[  728.581361]  libcomposite
[  728.584071]  configfs
[  728.586428]  aes_ce_blk
[  728.588960]  sata_rcar
[  728.591421]  crypto_simd
[  728.594039]  cryptd
[  728.596217]  libata
[  728.598396]  aes_ce_cipher
[  728.601188]  crc32_ce
[  728.603542]  ghash_ce
[  728.605896]  gf128mul
[  728.608250]  aes_arm64
[  728.610692]  scsi_mod
[  728.613046]  sha2_ce
[  728.615313]  xhci_plat_hcd
[  728.618106]  sha256_arm64
[  728.620811]  sha1_ce
[  728.623077]  renesas_usbhs
[  728.625869]  xhci_hcd
[  728.628243]  renesas_usb3
[  728.630948]  sha1_generic
[  728.633670]  ravb_streaming(C)
[  728.636814]  udc_core
[  728.639168]  cpufreq_dt
[  728.641697]  rcar_gen3_thermal
[  728.644840]  usb_dmac
[  728.647194]  pwm_rcar
[  728.649548]  thermal_sys
[  728.652165]  virt_dma
[  728.654519]  mch_core(C)
[  728.657137]  pwm_bl
[  728.659315]  snd_soc_rcar
[  728.662020]  snd_aloop
[  728.664462]  snd_soc_generic_card
[  728.667869]  snd_soc_ak4613
[  728.670749]  ipv6
[  728.672768]  autofs4
[  728.675052] CPU: 0 PID: 2545 Comm: modprobe Tainted: G    B   WC      4.14.47+ torvalds#152
[  728.682973] Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
[  728.690637] task: ffff8006ced38000 task.stack: ffff8006cf6c0000
[  728.696814] PC is at u_audio_stop_capture+0x70/0x268 [u_audio]
[  728.702896] LR is at u_audio_stop_capture+0x70/0x268 [u_audio]
[  728.708964] pc : [<ffff2000021e1618>] lr : [<ffff2000021e1618>] pstate: 60000145
[  728.716620] sp : ffff8006cf6c7a50
[  728.720154] x29: ffff8006cf6c7a50
[  728.723760] x28: ffff8006ced38000
[  728.727272] x27: ffff200008fd7000
[  728.730857] x26: ffff2000021d2340
[  728.734361] x25: 0000000000000000
[  728.737948] x24: ffff200009e94b08
[  728.741452] x23: 00000000000000a0
[  728.745052] x22: 00000000000000a8
[  728.748558] x21: 1ffff000d9ed8f7c
[  728.752142] x20: ffff8006d671a800
[  728.755646] x19: 0000000000000000
[  728.759231] x18: 0000000000000000
[  728.762736] x17: 0000ffffbc7c8f40
[  728.766320] x16: ffff200008213c4c
[  728.769823] x15: 0000000000000000
[  728.773408] x14: 0720072007200720
[  728.776912] x13: 0720072007200720
[  728.780497] x12: ffffffffffffffff
[  728.784001] x11: 0000000000000040
[  728.787598] x10: 0000000000001600
[  728.791103] x9 : ffff8006cf6c77a0
[  728.794689] x8 : ffff8006ced39660
[  728.798193] x7 : ffff20000811c738
[  728.801794] x6 : 0000000000000000
[  728.805299] x5 : dfff200000000000
[  728.808885] x4 : ffff8006ced38000
[  728.812390] x3 : ffff200008fb46e8
[  728.815976] x2 : 0000000000000007
[  728.819480] x1 : 3ba68643e7431500
[  728.823066] x0 : 0000000000000000
[  728.826574] Process modprobe (pid: 2545, stack limit = 0xffff8006cf6c0000)
[  728.833704] Call trace:
[  728.836292] Exception stack(0xffff8006cf6c7910 to 0xffff8006cf6c7a50)
[  728.842987] 7900:                                   0000000000000000 3ba68643e7431500
[  728.851084] 7920: 0000000000000007 ffff200008fb46e8 ffff8006ced38000 dfff200000000000
[  728.859173] 7940: 0000000000000000 ffff20000811c738 ffff8006ced39660 ffff8006cf6c77a0
[  728.867248] 7960: 0000000000001600 0000000000000040 ffffffffffffffff 0720072007200720
[  728.875323] 7980: 0720072007200720 0000000000000000 ffff200008213c4c 0000ffffbc7c8f40
[  728.883412] 79a0: 0000000000000000 0000000000000000 ffff8006d671a800 1ffff000d9ed8f7c
[  728.891485] 79c0: 00000000000000a8 00000000000000a0 ffff200009e94b08 0000000000000000
[  728.899561] 79e0: ffff2000021d2340 ffff200008fd7000 ffff8006ced38000 ffff8006cf6c7a50
[  728.907636] 7a00: ffff2000021e1618 ffff8006cf6c7a50 ffff2000021e1618 0000000060000145
[  728.915710] 7a20: 0000000000000008 0000000000000000 0000ffffffffffff 3ba68643e7431500
[  728.923780] 7a40: ffff8006cf6c7a50 ffff2000021e1618
[  728.928880] [<ffff2000021e1618>] u_audio_stop_capture+0x70/0x268 [u_audio]
[  728.936032] [<ffff2000021f8b7c>] afunc_disable+0x44/0x60 [usb_f_uac2]
[  728.942822] [<ffff20000218177c>] usb_remove_function+0x9c/0x210 [libcomposite]
[  728.950385] [<ffff200002183320>] remove_config.isra.2+0x1d8/0x218 [libcomposite]
[  728.958134] [<ffff200002186c54>] __composite_unbind+0x104/0x1f8 [libcomposite]
[  728.965689] [<ffff200002186d58>] composite_unbind+0x10/0x18 [libcomposite]
[  728.972882] [<ffff20000152f158>] usb_gadget_remove_driver+0xc0/0x170 [udc_core]
[  728.980522] [<ffff20000153154c>] usb_gadget_unregister_driver+0x1cc/0x258 [udc_core]
[  728.988638] [<ffff200002180de8>] usb_composite_unregister+0x10/0x18 [libcomposite]
[  728.996472] [<ffff2000021d035c>] audio_driver_exit+0x14/0x28 [g_audio]
[  729.003231] [<ffff200008213ed4>] SyS_delete_module+0x288/0x32c
[  729.009278] Exception stack(0xffff8006cf6c7ec0 to 0xffff8006cf6c8000)
[  729.015946] 7ec0: 0000000006136428 0000000000000800 0000000000000000 0000ffffd706efe8
[  729.024022] 7ee0: 0000ffffd706efe9 000000000000000a 1999999999999999 0000000000000000
[  729.032099] 7f00: 000000000000006a 000000000042c078 0000000000000000 0000000000000005
[  729.040172] 7f20: 0000000000000000 0000000000000000 0000000000000004 0000000000000000
[  729.048263] 7f40: 000000000042bfc8 0000ffffbc7c8f40 0000000000000000 00000000061363c0
[  729.056337] 7f60: 0000000006136428 0000000000000000 0000000000000000 0000000006136428
[  729.064411] 7f80: 000000000042c000 0000ffffd7071448 000000000042c000 0000000000000000
[  729.072484] 7fa0: 00000000061350c0 0000ffffd7070010 000000000041129c 0000ffffd7070010
[  729.080563] 7fc0: 0000ffffbc7c8f48 0000000060000000 0000000006136428 000000000000006a
[  729.088636] 7fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[  729.096733] [<ffff200008084780>] el0_svc_naked+0x34/0x38
[  729.102259] Code: 9597d1b3 aa1703e0 9102a276 958792b9 (f9405275)
[  729.108617] ---[ end trace 7560c5fa3d100243 ]---

After this patch is applied, the issue is fixed:
rcar-gen3:/home/root# modprobe g_audio
[   59.217127] g_audio gadget: afunc_bind:565 Error!
[   59.222329] g_audio ee020000.usb: failed to start g_audio: -19
modprobe: ERROR: could not insert 'g_audio': No such device
rcar-gen3:/home/root# modprobe -r g_audio
rcar-gen3:/home/root#

Fixes: f1d3861 ("usb: gadget: f_uac2: fix error handling at afunc_bind")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
heikomat pushed a commit that referenced this issue Aug 22, 2018
The change protects almost the whole body of u_audio_iso_complete()
function by PCM stream lock, this is mainly sufficient to avoid a race
between USB request completion and stream termination, the change
prevents a possibility of invalid memory access in interrupt context
by memcpy():

    Unable to handle kernel paging request at virtual address 00004e80
    pgd = c0004000
    [00004e80] *pgd=00000000
    Internal error: Oops: 817 [#1] PREEMPT SMP ARM
    CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G         C   3.14.54+ torvalds#117
    task: da180b80 ti: da192000 task.ti: da192000
    PC is at memcpy+0x50/0x330
    LR is at 0xcdd92b0e
    pc : [<c029ef30>]    lr : [<cdd92b0e>]    psr: 20000193
    sp : da193ce4  ip : dd86ae26  fp : 0000b180
    r10: daf81680  r9 : 00000000  r8 : d58a01ea
    r7 : 2c0b43e4  r6 : acdfb08b  r5 : 01a271cf  r4 : 87389377
    r3 : 69469782  r2 : 00000020  r1 : daf82fe0  r0 : 00004e80
    Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    Control: 10c5387d  Table: 2b70804a  DAC: 00000015
    Process ksoftirqd/0 (pid: 3, stack limit = 0xda192238)

Also added a check for potential !runtime condition, commonly it is
done by PCM_RUNTIME_CHECK(substream) in the beginning, however this
does not completely prevent from oopses in u_audio_iso_complete(),
because the proper protection scheme must be implemented in PCM
library functions.

An example of *not fixed* oops due to substream->runtime->*
dereference by snd_pcm_running(substream) from
snd_pcm_period_elapsed(), where substream->runtime is gone while
waiting the substream lock:

    Unable to handle kernel paging request at virtual address 6b6b6b6b
    pgd = db7e4000
    [6b6b6b6b] *pgd=00000000
    CPU: 0 PID: 193 Comm: klogd Tainted: G         C   3.14.54+ torvalds#118
    task: db5ac500 ti: db60c000 task.ti: db60c000
    PC is at snd_pcm_period_elapsed+0x48/0xd8 [snd_pcm]
    LR is at snd_pcm_period_elapsed+0x40/0xd8 [snd_pcm]
    pc : [<>]    lr : [<>]    psr: 60000193
    Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
    Control: 10c5387d  Table: 2b7e404a  DAC: 00000015
    Process klogd (pid: 193, stack limit = 0xdb60c238)
    [<>] (snd_pcm_period_elapsed [snd_pcm]) from [<>] (udc_irq+0x500/0xbbc)
    [<>] (udc_irq) from [<>] (ci_irq+0x280/0x304)
    [<>] (ci_irq) from [<>] (handle_irq_event_percpu+0xa4/0x40c)
    [<>] (handle_irq_event_percpu) from [<>] (handle_irq_event+0x3c/0x5c)
    [<>] (handle_irq_event) from [<>] (handle_fasteoi_irq+0xc4/0x110)
    [<>] (handle_fasteoi_irq) from [<>] (generic_handle_irq+0x20/0x30)
    [<>] (generic_handle_irq) from [<>] (handle_IRQ+0x80/0xc0)
    [<>] (handle_IRQ) from [<>] (gic_handle_irq+0x3c/0x60)
    [<>] (gic_handle_irq) from [<>] (__irq_svc+0x44/0x78)

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
[erosca: W/o this patch, with minimal instrumentation [1], I can
         consistently reproduce BUG: KASAN: use-after-free [2]]

[1] Instrumentation to reproduce issue [2]:
 diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
 index a72295c953bb..bd0b308024fe 100644
 --- a/drivers/usb/gadget/function/u_audio.c
 +++ b/drivers/usb/gadget/function/u_audio.c
 @@ -16,6 +16,7 @@
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
 +#include <linux/delay.h>

  #include "u_audio.h"

 @@ -147,6 +148,8 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)

 	spin_unlock_irqrestore(&prm->lock, flags);

 +	udelay(500); //delay here to increase probability of parallel activities
 +
 	/* Pack USB load in ALSA ring buffer */
 	pending = prm->dma_bytes - hw_ptr;

[2] After applying [1], below BUG occurs on Rcar-H3-Salvator-X board:
==================================================================
BUG: KASAN: use-after-free in u_audio_iso_complete+0x24c/0x520 [u_audio]
Read of size 8 at addr ffff8006cafcc248 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        WC      4.14.47+ torvalds#160
Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
Call trace:
[<ffff2000080925ac>] dump_backtrace+0x0/0x364
[<ffff200008092924>] show_stack+0x14/0x1c
[<ffff200008f8dbcc>] dump_stack+0x108/0x174
[<ffff2000083c71b8>] print_address_description+0x7c/0x32c
[<ffff2000083c78e8>] kasan_report+0x324/0x354
[<ffff2000083c6114>] __asan_load8+0x24/0x94
[<ffff2000021d1b34>] u_audio_iso_complete+0x24c/0x520 [u_audio]
[<ffff20000152fe50>] usb_gadget_giveback_request+0x480/0x4d0 [udc_core]
[<ffff200001860ab8>] usbhsg_queue_done+0x100/0x130 [renesas_usbhs]
[<ffff20000185f814>] usbhsf_pkt_handler+0x1a4/0x298 [renesas_usbhs]
[<ffff20000185fb38>] usbhsf_irq_ready+0x128/0x178 [renesas_usbhs]
[<ffff200001859cc8>] usbhs_interrupt+0x440/0x490 [renesas_usbhs]
[<ffff2000081a0288>] __handle_irq_event_percpu+0x594/0xa58
[<ffff2000081a07d0>] handle_irq_event_percpu+0x84/0x12c
[<ffff2000081a0928>] handle_irq_event+0xb0/0x10c
[<ffff2000081a8384>] handle_fasteoi_irq+0x1e0/0x2ec
[<ffff20000819e5f8>] generic_handle_irq+0x2c/0x44
[<ffff20000819f0d0>] __handle_domain_irq+0x190/0x194
[<ffff20000808177c>] gic_handle_irq+0x80/0xac
Exception stack(0xffff200009e97c80 to 0xffff200009e97dc0)
7c80: 0000000000000000 0000000000000000 0000000000000003 ffff200008179298
7ca0: ffff20000ae1c180 dfff200000000000 0000000000000000 ffff2000081f9a88
7cc0: ffff200009eb5960 ffff200009e97cf0 0000000000001600 ffff0400041b064b
7ce0: 0000000000000000 0000000000000002 0000000200000001 0000000000000001
7d00: ffff20000842197c 0000ffff958c4970 0000000000000000 ffff8006da0d5b80
7d20: ffff8006d4678498 0000000000000000 000000126bde0a8b ffff8006d4678480
7d40: 0000000000000000 000000126bdbea64 ffff200008fd0000 ffff8006fffff980
7d60: 00000000495f0018 ffff200009e97dc0 ffff200008b6c4ec ffff200009e97dc0
7d80: ffff200008b6c4f0 0000000020000145 ffff8006da0d5b80 ffff8006d4678498
7da0: ffffffffffffffff ffff8006d4678498 ffff200009e97dc0 ffff200008b6c4f0
[<ffff200008084034>] el1_irq+0xb4/0x12c
[<ffff200008b6c4f0>] cpuidle_enter_state+0x818/0x844
[<ffff200008b6c59c>] cpuidle_enter+0x18/0x20
[<ffff20000815f2e4>] call_cpuidle+0x98/0x9c
[<ffff20000815f674>] do_idle+0x214/0x264
[<ffff20000815facc>] cpu_startup_entry+0x20/0x24
[<ffff200008fb09d8>] rest_init+0x30c/0x320
[<ffff2000095f1338>] start_kernel+0x570/0x5b0
---<-snip->---

Fixes: 132fcb4 ("usb: gadget: Add Audio Class 2.0 Driver")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
heikomat pushed a commit that referenced this issue Aug 22, 2018
GC of set uses call_rcu() to destroy elements.
So that elements would be destroyed after destroying sets and chains.
But, elements should be destroyed before destroying sets and chains.
In order to wait calling call_rcu(), a rcu_barrier() is added.

In order to test correctly, below patch should be applied.
https://patchwork.ozlabs.org/patch/940883/

test scripts:
   %cat test.nft
   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict; flags timeout;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		   }
		   timeout 1s;
	   }
	   chain a0 {
	   }
   }
   flush ruleset

   [ ... ]

   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict; flags timeout;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		   }
		   timeout 1s;
	   }
	   chain a0 {
	   }
   }
   flush ruleset

Splat looks like:
[  200.795603] kernel BUG at net/netfilter/nf_tables_api.c:1363!
[  200.806944] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  200.812253] CPU: 1 PID: 1582 Comm: nft Not tainted 4.17.0+ torvalds#24
[  200.820297] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[  200.830309] RIP: 0010:nf_tables_chain_destroy.isra.34+0x62/0x240 [nf_tables]
[  200.838317] Code: 43 50 85 c0 74 26 48 8b 45 00 48 8b 4d 08 ba 54 05 00 00 48 c7 c6 60 6d 29 c0 48 c7 c7 c0 65 29 c0
4c 8b 40 08 e8 58 e5 fd f8 <0f> 0b 48 89 da 48 b8 00 00 00 00 00 fc ff
[  200.860366] RSP: 0000:ffff880118dbf4d0 EFLAGS: 00010282
[  200.866354] RAX: 0000000000000061 RBX: ffff88010cdeaf08 RCX: 0000000000000000
[  200.874355] RDX: 0000000000000061 RSI: 0000000000000008 RDI: ffffed00231b7e90
[  200.882361] RBP: ffff880118dbf4e8 R08: ffffed002373bcfb R09: ffffed002373bcfa
[  200.890354] R10: 0000000000000000 R11: ffffed002373bcfb R12: dead000000000200
[  200.898356] R13: dead000000000100 R14: ffffffffbb62af38 R15: dffffc0000000000
[  200.906354] FS:  00007fefc31fd700(0000) GS:ffff88011b800000(0000) knlGS:0000000000000000
[  200.915533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  200.922355] CR2: 0000557f1c8e9128 CR3: 0000000106880000 CR4: 00000000001006e0
[  200.930353] Call Trace:
[  200.932351]  ? nf_tables_commit+0x26f6/0x2c60 [nf_tables]
[  200.939525]  ? nf_tables_setelem_notify.constprop.49+0x1a0/0x1a0 [nf_tables]
[  200.947525]  ? nf_tables_delchain+0x6e0/0x6e0 [nf_tables]
[  200.952383]  ? nft_add_set_elem+0x1700/0x1700 [nf_tables]
[  200.959532]  ? nla_parse+0xab/0x230
[  200.963529]  ? nfnetlink_rcv_batch+0xd06/0x10d0 [nfnetlink]
[  200.968384]  ? nfnetlink_net_init+0x130/0x130 [nfnetlink]
[  200.975525]  ? debug_show_all_locks+0x290/0x290
[  200.980363]  ? debug_show_all_locks+0x290/0x290
[  200.986356]  ? sched_clock_cpu+0x132/0x170
[  200.990352]  ? find_held_lock+0x39/0x1b0
[  200.994355]  ? sched_clock_local+0x10d/0x130
[  200.999531]  ? memset+0x1f/0x40

Fixes: 9d09829 ("netfilter: nft_hash: add support for timeouts")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
This patch fixes below.
1. check null pointer of rb_next.
 rb_next can return null. so null check routine should be added.
2. add rcu_barrier in destroy routine.
 GC uses call_rcu to remove elements. but all elements should be
 removed before destroying set and chains. so that rcu_barrier is added.

test script:
   %cat test.nft
   table inet aa {
	   map map1 {
		   type ipv4_addr : verdict; flags interval, timeout;
		   elements = {
			   0-1 : jump a0,
			   3-4 : jump a0,
			   6-7 : jump a0,
			   9-10 : jump a0,
			   12-13 : jump a0,
			   15-16 : jump a0,
			   18-19 : jump a0,
			   21-22 : jump a0,
			   24-25 : jump a0,
			   27-28 : jump a0,
		   }
		   timeout 1s;
	   }
	   chain a0 {
	   }
   }
   flush ruleset
   table inet aa {
	   map map1 {
		   type ipv4_addr : verdict; flags interval, timeout;
		   elements = {
			   0-1 : jump a0,
			   3-4 : jump a0,
			   6-7 : jump a0,
			   9-10 : jump a0,
			   12-13 : jump a0,
			   15-16 : jump a0,
			   18-19 : jump a0,
			   21-22 : jump a0,
			   24-25 : jump a0,
			   27-28 : jump a0,
		   }
		   timeout 1s;
	   }
	   chain a0 {
	   }
   }
   flush ruleset

splat looks like:
[ 2402.419838] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 2402.428433] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 2402.429343] CPU: 1 PID: 1350 Comm: kworker/1:1 Not tainted 4.18.0-rc2+ #1
[ 2402.429343] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 03/23/2017
[ 2402.429343] Workqueue: events_power_efficient nft_rbtree_gc [nft_set_rbtree]
[ 2402.429343] RIP: 0010:rb_next+0x1e/0x130
[ 2402.429343] Code: e9 de f2 ff ff 0f 1f 80 00 00 00 00 41 55 48 89 fa 41 54 55 53 48 c1 ea 03 48 b8 00 00 00 0
[ 2402.429343] RSP: 0018:ffff880105f77678 EFLAGS: 00010296
[ 2402.429343] RAX: dffffc0000000000 RBX: ffff8801143e3428 RCX: 1ffff1002287c69c
[ 2402.429343] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
[ 2402.429343] RBP: 0000000000000000 R08: ffffed0016aabc24 R09: ffffed0016aabc24
[ 2402.429343] R10: 0000000000000001 R11: ffffed0016aabc23 R12: 0000000000000000
[ 2402.429343] R13: ffff8800b6933388 R14: dffffc0000000000 R15: ffff8801143e3440
[ 2402.534486] kasan: CONFIG_KASAN_INLINE enabled
[ 2402.534212] FS:  0000000000000000(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 2402.534212] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2402.534212] CR2: 0000000000863008 CR3: 00000000a3c16000 CR4: 00000000001006e0
[ 2402.534212] Call Trace:
[ 2402.534212]  nft_rbtree_gc+0x2b5/0x5f0 [nft_set_rbtree]
[ 2402.534212]  process_one_work+0xc1b/0x1ee0
[ 2402.540329] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 2402.534212]  ? _raw_spin_unlock_irq+0x29/0x40
[ 2402.534212]  ? pwq_dec_nr_in_flight+0x3e0/0x3e0
[ 2402.534212]  ? set_load_weight+0x270/0x270
[ 2402.534212]  ? __schedule+0x6ea/0x1fb0
[ 2402.534212]  ? __sched_text_start+0x8/0x8
[ 2402.534212]  ? save_trace+0x320/0x320
[ 2402.534212]  ? sched_clock_local+0xe2/0x150
[ 2402.534212]  ? find_held_lock+0x39/0x1c0
[ 2402.534212]  ? worker_thread+0x35f/0x1150
[ 2402.534212]  ? lock_contended+0xe90/0xe90
[ 2402.534212]  ? __lock_acquire+0x4520/0x4520
[ 2402.534212]  ? do_raw_spin_unlock+0xb1/0x350
[ 2402.534212]  ? do_raw_spin_trylock+0x111/0x1b0
[ 2402.534212]  ? do_raw_spin_lock+0x1f0/0x1f0
[ 2402.534212]  worker_thread+0x169/0x1150

Fixes: 8d8540c("netfilter: nft_set_rbtree: add timeout support")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
syzbot caught a NULL deref [1], caused by skb_segment()

skb_segment() has many "goto err;" that assume the @err variable
contains -ENOMEM.

A successful call to __skb_linearize() should not clear @err,
otherwise a subsequent memory allocation error could return NULL.

While we are at it, we might use -EINVAL instead of -ENOMEM when
MAX_SKB_FRAGS limit is reached.

[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 13285 Comm: syz-executor3 Not tainted 4.18.0-rc4+ torvalds#146
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_gso_segment+0x3dc/0x1780 net/ipv4/tcp_offload.c:106
Code: f0 ff ff 0f 87 1c fd ff ff e8 00 88 0b fb 48 8b 75 d0 48 b9 00 00 00 00 00 fc ff df 48 8d be 90 00 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 08 48 8d 86 94 00 00 00 48 89 c6 83 e0 07 48 c1 ee 03 0f
RSP: 0018:ffff88019b7fd060 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000020 RCX: dffffc0000000000
RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000090
RBP: ffff88019b7fd0f0 R08: ffff88019510e0c0 R09: ffffed003b5c46d6
R10: ffffed003b5c46d6 R11: ffff8801dae236b3 R12: 0000000000000001
R13: ffff8801d6c581f4 R14: 0000000000000000 R15: ffff8801d6c58128
FS:  00007fcae64d6700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e8664 CR3: 00000001b669b000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tcp4_gso_segment+0x1c3/0x440 net/ipv4/tcp_offload.c:54
 inet_gso_segment+0x64e/0x12d0 net/ipv4/af_inet.c:1342
 inet_gso_segment+0x64e/0x12d0 net/ipv4/af_inet.c:1342
 skb_mac_gso_segment+0x3b5/0x740 net/core/dev.c:2792
 __skb_gso_segment+0x3c3/0x880 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4099 [inline]
 validate_xmit_skb+0x640/0xf30 net/core/dev.c:3104
 __dev_queue_xmit+0xc14/0x3910 net/core/dev.c:3561
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3602
 neigh_hh_output include/net/neighbour.h:473 [inline]
 neigh_output include/net/neighbour.h:481 [inline]
 ip_finish_output2+0x1063/0x1860 net/ipv4/ip_output.c:229
 ip_finish_output+0x841/0xfa0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x223/0x880 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x567/0x850 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x1598/0x3af1 net/ipv4/ip_tunnel.c:778
 ipip_tunnel_xmit+0x264/0x2c0 net/ipv4/ipip.c:308
 __netdev_start_xmit include/linux/netdevice.h:4148 [inline]
 netdev_start_xmit include/linux/netdevice.h:4157 [inline]
 xmit_one net/core/dev.c:3034 [inline]
 dev_hard_start_xmit+0x26c/0xc30 net/core/dev.c:3050
 __dev_queue_xmit+0x29ef/0x3910 net/core/dev.c:3569
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3602
 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1403
 neigh_output include/net/neighbour.h:483 [inline]
 ip_finish_output2+0xa67/0x1860 net/ipv4/ip_output.c:229
 ip_finish_output+0x841/0xfa0 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x223/0x880 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x9df/0x1f80 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x1bf9/0x3f10 net/ipv4/tcp_output.c:1168
 tcp_write_xmit+0x1641/0x5c20 net/ipv4/tcp_output.c:2363
 __tcp_push_pending_frames+0xb2/0x290 net/ipv4/tcp_output.c:2536
 tcp_push+0x638/0x8c0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x2ec5/0x3f00 net/ipv4/tcp.c:1410
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:651
 __sys_sendto+0x3d7/0x670 net/socket.c:1797
 __do_sys_sendto net/socket.c:1809 [inline]
 __se_sys_sendto net/socket.c:1805 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1805
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcae64d5c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fcae64d66d4 RCX: 0000000000455ab9
RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000004c1145 R14: 00000000004d1818 R15: 0000000000000006
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)

Fixes: ddff00d ("net: Move skb_has_shared_frag check out of GRE code and into segmentation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
The original mapping for the DW5821e was done using a development
version of the firmware. Confirmed with the vendor that the final
USB layout ends up exposing the QMI control/data ports in USB
config #1, interface #0, not in interface #1 (which is now a HID
interface).

T:  Bus=01 Lev=03 Prnt=04 Port=00 Cnt=01 Dev#= 16 Spd=480 MxCh= 0
D:  Ver= 2.10 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  2
P:  Vendor=413c ProdID=81d7 Rev=03.18
S:  Manufacturer=DELL
S:  Product=DW5821e Snapdragon X20 LTE
S:  SerialNumber=0123456789ABCDEF
C:  #Ifs= 6 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
I:  If#= 1 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbhid
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 5 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option

Fixes: e7e197e ("qmi_wwan: add support for the Dell Wireless 5821e module")
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
If the registration fails then mdio_unregister is called.
However at unbind the unregister ia attempted again resulting
in the below crash

[   73.544038] kernel BUG at drivers/net/phy/mdio_bus.c:415!
[   73.549362] Internal error: Oops - BUG: 0 [#1] SMP
[   73.554127] Modules linked in:
[   73.557168] CPU: 0 PID: 2249 Comm: sh Not tainted 4.14.0 torvalds#183
[   73.562895] Hardware name: xlnx,zynqmp (DT)
[   73.567062] task: ffffffc879e41180 task.stack: ffffff800cbe0000
[   73.572973] PC is at mdiobus_unregister+0x84/0x88
[   73.577656] LR is at axienet_mdio_teardown+0x18/0x30
[   73.582601] pc : [<ffffff80085fa4cc>] lr : [<ffffff8008616858>]
pstate: 20000145
[   73.589981] sp : ffffff800cbe3c30
[   73.593277] x29: ffffff800cbe3c30 x28: ffffffc879e41180
[   73.598573] x27: ffffff8008a21000 x26: 0000000000000040
[   73.603868] x25: 0000000000000124 x24: ffffffc879efe920
[   73.609164] x23: 0000000000000060 x22: ffffffc879e02000
[   73.614459] x21: ffffffc879e02800 x20: ffffffc87b0b8870
[   73.619754] x19: ffffffc879e02800 x18: 000000000000025d
[   73.625050] x17: 0000007f9a719ad0 x16: ffffff8008195bd8
[   73.630345] x15: 0000007f9a6b3d00 x14: 0000000000000010
[   73.635640] x13: 74656e7265687465 x12: 0000000000000030
[   73.640935] x11: 0000000000000030 x10: 0101010101010101
[   73.646231] x9 : 241f394f42533300 x8 : ffffffc8799f6e98
[   73.651526] x7 : ffffffc8799f6f18 x6 : ffffffc87b0ba318
[   73.656822] x5 : ffffffc87b0ba498 x4 : 0000000000000000
[   73.662117] x3 : 0000000000000000 x2 : 0000000000000008
[   73.667412] x1 : 0000000000000004 x0 : ffffffc8799f4000
[   73.672708] Process sh (pid: 2249, stack limit = 0xffffff800cbe0000)

Fix the same by making the bus NULL on unregister.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
Running the following:

 # cd /sys/kernel/debug/tracing
 # echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
 # echo snapshot > events/sched/sched_switch/trigger

Triggers the following bug:

 ------------[ cut here ]------------
 kernel BUG at mm/slub.c:296!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ torvalds#1066
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:kfree+0x16c/0x180
 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
 RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
 R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
 R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
 FS:  00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
 Call Trace:
  event_trigger_callback+0xee/0x1d0
  event_trigger_write+0xfc/0x1a0
  __vfs_write+0x33/0x190
  ? handle_mm_fault+0x115/0x230
  ? _cond_resched+0x16/0x40
  vfs_write+0xb0/0x190
  ksys_write+0x52/0xc0
  do_syscall_64+0x5a/0x160
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7f363e16ab50
 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
 ---[ end trace d301afa879ddfa25 ]---

The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.

By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.

Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home

Cc: stable@vger.kerne.org
Fixes: 93e31ff ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
Registration of a memory region(MR) through FRMR/fastreg(unlike FMR)
needs a connection/qp. With a proxy qp, this dependency on connection
will be removed, but that needs more infrastructure patches, which is a
work in progress.

As an intermediate fix, the get_mr returns EOPNOTSUPP when connection
details are not populated. The MR registration through sendmsg() will
continue to work even with fast registration, since connection in this
case is formed upfront.

This patch fixes the following crash:
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 1 PID: 4244 Comm: syzkaller468044 Not tainted 4.16.0-rc6+ torvalds#361
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:rds_ib_get_mr+0x5c/0x230 net/rds/ib_rdma.c:544
RSP: 0018:ffff8801b059f890 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801b07e1300 RCX: ffffffff8562d96e
RDX: 000000000000000d RSI: 0000000000000001 RDI: 0000000000000068
RBP: ffff8801b059f8b8 R08: ffffed0036274244 R09: ffff8801b13a1200
R10: 0000000000000004 R11: ffffed0036274243 R12: ffff8801b13a1200
R13: 0000000000000001 R14: ffff8801ca09fa9c R15: 0000000000000000
FS:  00007f4d050af700(0000) GS:ffff8801db300000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4d050aee78 CR3: 00000001b0d9b006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __rds_rdma_map+0x710/0x1050 net/rds/rdma.c:271
 rds_get_mr_for_dest+0x1d4/0x2c0 net/rds/rdma.c:357
 rds_setsockopt+0x6cc/0x980 net/rds/af_rds.c:347
 SYSC_setsockopt net/socket.c:1849 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1828
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4456d9
RSP: 002b:00007f4d050aedb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 00000000004456d9
RDX: 0000000000000007 RSI: 0000000000000114 RDI: 0000000000000004
RBP: 00000000006dac38 R08: 00000000000000a0 R09: 0000000000000000
R10: 0000000020000380 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbfb36d6f R14: 00007f4d050af9c0 R15: 0000000000000005
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 cc 01 00 00 4c 8b bb 80 04 00 00
48
b8 00 00 00 00 00 fc ff df 49 8d 7f 68 48 89 fa 48 c1 ea 03 <80> 3c 02
00 0f
85 9c 01 00 00 4d 8b 7f 68 48 b8 00 00 00 00 00
RIP: rds_ib_get_mr+0x5c/0x230 net/rds/ib_rdma.c:544 RSP:
ffff8801b059f890
---[ end trace 7e1cea13b85473b0 ]---

Reported-by: syzbot+b51c77ef956678a65834@syzkaller.appspotmail.com
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Avinash Repaka <avinash.repaka@oracle.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
…ilure

While forking, if delayacct init fails due to memory shortage, it
continues expecting all delayacct users to check task->delays pointer
against NULL before dereferencing it, which all of them used to do.

Commit c96f547 ("delayacct: Account blkio completion on the correct
task"), while updating delayacct_blkio_end() to take the target task
instead of always using %current, made the function test NULL on
%current->delays and then continue to operated on @p->delays.  If
%current succeeded init while @p didn't, it leads to the following
crash.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
 IP: __delayacct_blkio_end+0xc/0x40
 PGD 8000001fd07e1067 P4D 8000001fd07e1067 PUD 1fcffbb067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 4 PID: 25774 Comm: QIOThread0 Not tainted 4.16.0-9_fbk1_rc2_1180_g6b593215b4d7 #9
 RIP: 0010:__delayacct_blkio_end+0xc/0x40
 Call Trace:
  try_to_wake_up+0x2c0/0x600
  autoremove_wake_function+0xe/0x30
  __wake_up_common+0x74/0x120
  wake_up_page_bit+0x9c/0xe0
  mpage_end_io+0x27/0x70
  blk_update_request+0x78/0x2c0
  scsi_end_request+0x2c/0x1e0
  scsi_io_completion+0x20b/0x5f0
  blk_mq_complete_request+0xa2/0x100
  ata_scsi_qc_complete+0x79/0x400
  ata_qc_complete_multiple+0x86/0xd0
  ahci_handle_port_interrupt+0xc9/0x5c0
  ahci_handle_port_intr+0x54/0xb0
  ahci_single_level_irq_intr+0x3b/0x60
  __handle_irq_event_percpu+0x43/0x190
  handle_irq_event_percpu+0x20/0x50
  handle_irq_event+0x2a/0x50
  handle_edge_irq+0x80/0x1c0
  handle_irq+0xaf/0x120
  do_IRQ+0x41/0xc0
  common_interrupt+0xf/0xf

Fix it by updating delayacct_blkio_end() check @p->delays instead.

Link: http://lkml.kernel.org/r/20180724175542.GP1934745@devbig577.frc2.facebook.com
Fixes: c96f547 ("delayacct: Account blkio completion on the correct task")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dave Jones <dsj@fb.com>
Debugged-by: Dave Jones <dsj@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Snyder <joshs@netflix.com>
Cc: <stable@vger.kernel.org>	[4.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA.  This is unreliable as ->mmap may not set ->vm_ops.

False-positive vma_is_anonymous() may lead to crashes:

	next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
	prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
	pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
	flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
	------------[ cut here ]------------
	kernel BUG at mm/memory.c:1422!
	invalid opcode: 0000 [#1] SMP KASAN
	CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ torvalds#136
	Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
	01/01/2011
	RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
	RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
	RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
	RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
	Call Trace:
	 unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
	 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
	 unmap_mapping_range_vma mm/memory.c:2792 [inline]
	 unmap_mapping_range_tree mm/memory.c:2813 [inline]
	 unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
	 unmap_mapping_range+0x48/0x60 mm/memory.c:2880
	 truncate_pagecache+0x54/0x90 mm/truncate.c:800
	 truncate_setsize+0x70/0xb0 mm/truncate.c:826
	 simple_setattr+0xe9/0x110 fs/libfs.c:409
	 notify_change+0xf13/0x10f0 fs/attr.c:335
	 do_truncate+0x1ac/0x2b0 fs/open.c:63
	 do_sys_ftruncate+0x492/0x560 fs/open.c:205
	 __do_sys_ftruncate fs/open.c:215 [inline]
	 __se_sys_ftruncate fs/open.c:213 [inline]
	 __x64_sys_ftruncate+0x59/0x80 fs/open.c:213
	 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reproducer:

	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <fcntl.h>

	#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
	#define KCOV_ENABLE			_IO('c', 100)
	#define KCOV_DISABLE			_IO('c', 101)
	#define COVER_SIZE			(1024<<10)

	#define KCOV_TRACE_PC  0
	#define KCOV_TRACE_CMP 1

	int main(int argc, char **argv)
	{
		int fd;
		unsigned long *cover;

		system("mount -t debugfs none /sys/kernel/debug");
		fd = open("/sys/kernel/debug/kcov", O_RDWR);
		ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		munmap(cover, COVER_SIZE * sizeof(unsigned long));
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
		ftruncate(fd, 3UL << 20);
		return 0;
	}

This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.

If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops.  This way we will have non-NULL ->vm_ops for all VMAs.

Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
bpf_parse_prog() is protected by rcu_read_lock().
so that GFP_KERNEL is not allowed in the bpf_parse_prog().

[51015.579396] =============================
[51015.579418] WARNING: suspicious RCU usage
[51015.579444] 4.18.0-rc6+ torvalds#208 Not tainted
[51015.579464] -----------------------------
[51015.579488] ./include/linux/rcupdate.h:303 Illegal context switch in RCU read-side critical section!
[51015.579510] other info that might help us debug this:
[51015.579532] rcu_scheduler_active = 2, debug_locks = 1
[51015.579556] 2 locks held by ip/1861:
[51015.579577]  #0: 00000000a8c12fd1 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x2e0/0x910
[51015.579711]  #1: 00000000bf815f8e (rcu_read_lock){....}, at: lwtunnel_build_state+0x96/0x390
[51015.579842] stack backtrace:
[51015.579869] CPU: 0 PID: 1861 Comm: ip Not tainted 4.18.0-rc6+ torvalds#208
[51015.579891] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[51015.579911] Call Trace:
[51015.579950]  dump_stack+0x74/0xbb
[51015.580000]  ___might_sleep+0x16b/0x3a0
[51015.580047]  __kmalloc_track_caller+0x220/0x380
[51015.580077]  kmemdup+0x1c/0x40
[51015.580077]  bpf_parse_prog+0x10e/0x230
[51015.580164]  ? kasan_kmalloc+0xa0/0xd0
[51015.580164]  ? bpf_destroy_state+0x30/0x30
[51015.580164]  ? bpf_build_state+0xe2/0x3e0
[51015.580164]  bpf_build_state+0x1bb/0x3e0
[51015.580164]  ? bpf_parse_prog+0x230/0x230
[51015.580164]  ? lock_is_held_type+0x123/0x1a0
[51015.580164]  lwtunnel_build_state+0x1aa/0x390
[51015.580164]  fib_create_info+0x1579/0x33d0
[51015.580164]  ? sched_clock_local+0xe2/0x150
[51015.580164]  ? fib_info_update_nh_saddr+0x1f0/0x1f0
[51015.580164]  ? sched_clock_local+0xe2/0x150
[51015.580164]  fib_table_insert+0x201/0x1990
[51015.580164]  ? lock_downgrade+0x610/0x610
[51015.580164]  ? fib_table_lookup+0x1920/0x1920
[51015.580164]  ? lwtunnel_valid_encap_type.part.6+0xcb/0x3a0
[51015.580164]  ? rtm_to_fib_config+0x637/0xbd0
[51015.580164]  inet_rtm_newroute+0xed/0x1b0
[51015.580164]  ? rtm_to_fib_config+0xbd0/0xbd0
[51015.580164]  rtnetlink_rcv_msg+0x331/0x910
[ ... ]

Fixes: 3a0af8f ("bpf: BPF for lightweight tunnel infrastructure")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 #3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 #4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 #5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 #6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 #7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 #8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 #9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: stable@vger.kernel.org
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
heikomat pushed a commit that referenced this issue Aug 22, 2018
syzbot found that the following sequence produces a LOCKDEP splat [1]

ip link add bond10 type bond
ip link add bond11 type bond
ip link set bond11 master bond10

To fix this, we can use the already provided nest_level.

This patch also provides correct nesting for dev->addr_list_lock

[1]
WARNING: possible recursive locking detected
4.18.0-rc6+ torvalds#167 Not tainted
--------------------------------------------
syz-executor751/4439 is trying to acquire lock:
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426

but task is already holding lock:
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&bond->stats_lock)->rlock);
  lock(&(&bond->stats_lock)->rlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz-executor751/4439:
 #0: (____ptrval____) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
 #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
 #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426
 #2: (____ptrval____) (rcu_read_lock){....}, at: bond_get_stats+0x0/0x560 include/linux/compiler.h:215

stack backtrace:
CPU: 0 PID: 4439 Comm: syz-executor751 Not tainted 4.18.0-rc6+ torvalds#167
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_deadlock_bug kernel/locking/lockdep.c:1765 [inline]
 check_deadlock kernel/locking/lockdep.c:1809 [inline]
 validate_chain kernel/locking/lockdep.c:2405 [inline]
 __lock_acquire.cold.64+0x1fb/0x486 kernel/locking/lockdep.c:3435
 lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:310 [inline]
 bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426
 dev_get_stats+0x10f/0x470 net/core/dev.c:8316
 bond_get_stats+0x232/0x560 drivers/net/bonding/bond_main.c:3432
 dev_get_stats+0x10f/0x470 net/core/dev.c:8316
 rtnl_fill_stats+0x4d/0xac0 net/core/rtnetlink.c:1169
 rtnl_fill_ifinfo+0x1aa6/0x3fb0 net/core/rtnetlink.c:1611
 rtmsg_ifinfo_build_skb+0xc8/0x190 net/core/rtnetlink.c:3268
 rtmsg_ifinfo_event.part.30+0x45/0xe0 net/core/rtnetlink.c:3300
 rtmsg_ifinfo_event net/core/rtnetlink.c:3297 [inline]
 rtnetlink_event+0x144/0x170 net/core/rtnetlink.c:4716
 notifier_call_chain+0x180/0x390 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1735
 call_netdevice_notifiers net/core/dev.c:1753 [inline]
 netdev_features_change net/core/dev.c:1321 [inline]
 netdev_change_features+0xb3/0x110 net/core/dev.c:7759
 bond_compute_features.isra.47+0x585/0xa50 drivers/net/bonding/bond_main.c:1120
 bond_enslave+0x1b25/0x5da0 drivers/net/bonding/bond_main.c:1755
 bond_do_ioctl+0x7cb/0xae0 drivers/net/bonding/bond_main.c:3528
 dev_ifsioc+0x43c/0xb30 net/core/dev_ioctl.c:327
 dev_ioctl+0x1b5/0xcc0 net/core/dev_ioctl.c:493
 sock_do_ioctl+0x1d3/0x3e0 net/socket.c:992
 sock_ioctl+0x30d/0x680 net/socket.c:1093
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440859
Code: e8 2c af 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc51a92878 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440859
RDX: 0000000020000040 RSI: 0000000000008990 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000022d5880 R11: 0000000000000213 R12: 0000000000007390
R13: 0000000000401db0 R14: 0000000000000000 R15: 0000000000000000

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>

Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
Amit Pundir and Youling in parallel reported crashes with recent
mainline kernels running Android:

  F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  F DEBUG   : Build fingerprint: 'Android/db410c32_only/db410c32_only:Q/OC-MR1/102:userdebug/test-key
  F DEBUG   : Revision: '0'
  F DEBUG   : ABI: 'arm'
  F DEBUG   : pid: 2261, tid: 2261, name: zygote  >>> zygote <<<
  F DEBUG   : signal 7 (SIGBUS), code 2 (BUS_ADRERR), fault addr 0xec00008
  ... <snip> ...
  F DEBUG   : backtrace:
  F DEBUG   :     #00 pc 00001c04  /system/lib/libc.so (memset+48)
  F DEBUG   :     #1 pc 0010c513  /system/lib/libart.so (create_mspace_with_base+82)
  F DEBUG   :     #2 pc 0015c601  /system/lib/libart.so (art::gc::space::DlMallocSpace::CreateMspace(void*, unsigned int, unsigned int)+40)
  F DEBUG   :     #3 pc 0015c3ed  /system/lib/libart.so (art::gc::space::DlMallocSpace::CreateFromMemMap(art::MemMap*, std::__1::basic_string<char, std::__ 1::char_traits<char>, std::__1::allocator<char>> const&, unsigned int, unsigned int, unsigned int, unsigned int, bool)+36)
  ...

This was bisected back to commit bfd40ea ("mm: fix
vma_is_anonymous() false-positives").

create_mspace_with_base() in the trace above, utilizes ashmem, and with
ashmem, for shared mappings we use shmem_zero_setup(), which sets the
vma->vm_ops to &shmem_vm_ops.  But for private ashmem mappings nothing
sets the vma->vm_ops.

Looking at the problematic patch, it seems to add a requirement that one
call vma_set_anonymous() on a vma, otherwise the dummy_vm_ops will be
used.  Using the dummy_vm_ops seem to triggger SIGBUS when traversing
unmapped pages.

Thus, this patch adds a call to vma_set_anonymous() for ashmem private
mappings and seems to avoid the reported problem.

Fixes: bfd40ea ("mm: fix vma_is_anonymous() false-positives")
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Colin Cross <ccross@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Reported-by: Amit Pundir <amit.pundir@linaro.org>
Reported-by: Youling 257 <youling257@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
…ment enabled

Surround scsi_execute() calls with scsi_autopm_get_device() and
scsi_autopm_put_device(). Note: removing sr_mutex protection from the
scsi_cd_get() and scsi_cd_put() calls is safe because the purpose of
sr_mutex is to serialize cdrom_*() calls.

This patch avoids that complaints similar to the following appear in the
kernel log if runtime power management is enabled:

INFO: task systemd-udevd:650 blocked for more than 120 seconds.
     Not tainted 4.18.0-rc7-dbg+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
systemd-udevd   D28176   650    513 0x00000104
Call Trace:
__schedule+0x444/0xfe0
schedule+0x4e/0xe0
schedule_preempt_disabled+0x18/0x30
__mutex_lock+0x41c/0xc70
mutex_lock_nested+0x1b/0x20
__blkdev_get+0x106/0x970
blkdev_get+0x22c/0x5a0
blkdev_open+0xe9/0x100
do_dentry_open.isra.19+0x33e/0x570
vfs_open+0x7c/0xd0
path_openat+0x6e3/0x1120
do_filp_open+0x11c/0x1c0
do_sys_open+0x208/0x2d0
__x64_sys_openat+0x59/0x70
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
heikomat pushed a commit that referenced this issue Aug 22, 2018
The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value
can lead to undefined behavior [1].

In order to fix this use a gradual shift of the window with a 'while'
loop, similar to what tcp_cwnd_restart() is doing.

When comparing delta and RTO there is a minor difference between TCP
and DCCP, the last one also invokes dccp_cwnd_restart() and reduces
'cwnd' if delta equals RTO. That case is preserved in this change.

[1]:
[40850.963623] UBSAN: Undefined behaviour in net/dccp/ccids/ccid2.c:237:7
[40851.043858] shift exponent 67 is too large for 32-bit type 'unsigned int'
[40851.127163] CPU: 3 PID: 15940 Comm: netstress Tainted: G        W   E     4.18.0-rc7.x86_64 #1
...
[40851.377176] Call Trace:
[40851.408503]  dump_stack+0xf1/0x17b
[40851.451331]  ? show_regs_print_info+0x5/0x5
[40851.503555]  ubsan_epilogue+0x9/0x7c
[40851.548363]  __ubsan_handle_shift_out_of_bounds+0x25b/0x2b4
[40851.617109]  ? __ubsan_handle_load_invalid_value+0x18f/0x18f
[40851.686796]  ? xfrm4_output_finish+0x80/0x80
[40851.739827]  ? lock_downgrade+0x6d0/0x6d0
[40851.789744]  ? xfrm4_prepare_output+0x160/0x160
[40851.845912]  ? ip_queue_xmit+0x810/0x1db0
[40851.895845]  ? ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40851.963530]  ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40852.029063]  dccp_xmit_packet+0x1d3/0x720 [dccp]
[40852.086254]  dccp_write_xmit+0x116/0x1d0 [dccp]
[40852.142412]  dccp_sendmsg+0x428/0xb20 [dccp]
[40852.195454]  ? inet_dccp_listen+0x200/0x200 [dccp]
[40852.254833]  ? sched_clock+0x5/0x10
[40852.298508]  ? sched_clock+0x5/0x10
[40852.342194]  ? inet_create+0xdf0/0xdf0
[40852.388988]  sock_sendmsg+0xd9/0x160
...

Fixes: 113ced1 ("dccp ccid-2: Perform congestion-window validation")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
If zram supports writeback feature, it's no longer a
BD_CAP_SYNCHRONOUS_IO device beause zram does asynchronous IO operations
for incompressible pages.

Do not pretend to be synchronous IO device.  It makes the system very
sluggish due to waiting for IO completion from upper layers.

Furthermore, it causes a user-after-free problem because swap thinks the
opearion is done when the IO functions returns so it can free the page
(e.g., lock_page_or_retry and goto out_release in do_swap_page) but in
fact, IO is asynchronous so the driver could access a just freed page
afterward.

This patch fixes the problem.

  BUG: Bad page state in process qemu-system-x86  pfn:3dfab21
  page:ffffdfb137eac840 count:0 mapcount:0 mapping:0000000000000000 index:0x1
  flags: 0x17fffc000000008(uptodate)
  raw: 017fffc000000008 dead000000000100 dead000000000200 0000000000000000
  raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set
  bad because of flags: 0x8(uptodate)
  CPU: 4 PID: 1039 Comm: qemu-system-x86 Tainted: G    B 4.18.0-rc5+ #1
  Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0b 05/02/2017
  Call Trace:
    dump_stack+0x5c/0x7b
    bad_page+0xba/0x120
    get_page_from_freelist+0x1016/0x1250
    __alloc_pages_nodemask+0xfa/0x250
    alloc_pages_vma+0x7c/0x1c0
    do_swap_page+0x347/0x920
    __handle_mm_fault+0x7b4/0x1110
    handle_mm_fault+0xfc/0x1f0
    __get_user_pages+0x12f/0x690
    get_user_pages_unlocked+0x148/0x1f0
    __gfn_to_pfn_memslot+0xff/0x3c0 [kvm]
    try_async_pf+0x87/0x230 [kvm]
    tdp_page_fault+0x132/0x290 [kvm]
    kvm_mmu_page_fault+0x74/0x570 [kvm]
    kvm_arch_vcpu_ioctl_run+0x9b3/0x1990 [kvm]
    kvm_vcpu_ioctl+0x388/0x5d0 [kvm]
    do_vfs_ioctl+0xa2/0x630
    ksys_ioctl+0x70/0x80
    __x64_sys_ioctl+0x16/0x20
    do_syscall_64+0x55/0x100
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/
Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org
[minchan@kernel.org: fix changelog, add comment]
 Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/
 Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org
 Link: http://lkml.kernel.org/r/20180805233722.217347-1-minchan@kernel.org
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Tino Lehnig <tino.lehnig@contabo.de>
Tested-by: Tino Lehnig <tino.lehnig@contabo.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>	[4.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
the control action in the common member of struct tcf_csum must be a valid
value, as it can contain the chain index when 'goto chain' is used. Ensure
that the control action can be read as x->tcfa_action, when x is a pointer
to struct tc_action and x->ops->type is TCA_ACT_CSUM, to prevent the
following command:

  # tc filter add dev $h2 ingress protocol ip pref 1 handle 101 flower \
  > $tcflags dst_mac $h2mac action csum ip or tcp or udp or sctp goto chain 1

from triggering a NULL pointer dereference when a matching packet is
received.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 PGD 800000010416b067 P4D 800000010416b067 PUD 1041be067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 3072 Comm: mausezahn Tainted: G            E     4.18.0-rc2.auguri+ torvalds#421
 Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.58 02/07/2013
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffa020dea03c40 EFLAGS: 00010246
 RAX: 0000000020000001 RBX: ffffa020d7ccef00 RCX: 0000000000000054
 RDX: 0000000000000000 RSI: ffffa020ca5ae000 RDI: ffffa020d7ccef00
 RBP: ffffa020dea03e60 R08: 0000000000000000 R09: ffffa020dea03c9c
 R10: ffffa020dea03c78 R11: 0000000000000008 R12: ffffa020d3fe4f00
 R13: ffffa020d3fe4f08 R14: 0000000000000001 R15: ffffa020d53ca300
 FS:  00007f5a46942740(0000) GS:ffffa020dea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000104218002 CR4: 00000000001606f0
 Call Trace:
  <IRQ>
  fl_classify+0x1ad/0x1c0 [cls_flower]
  ? arp_rcv+0x121/0x1b0
  ? __x2apic_send_IPI_dest+0x40/0x40
  ? smp_reschedule_interrupt+0x1c/0xd0
  ? reschedule_interrupt+0xf/0x20
  ? reschedule_interrupt+0xa/0x20
  ? device_is_rmrr_locked+0xe/0x50
  ? iommu_should_identity_map+0x49/0xd0
  ? __intel_map_single+0x30/0x140
  ? e1000e_update_rdt_wa.isra.52+0x22/0xb0 [e1000e]
  ? e1000_alloc_rx_buffers+0x233/0x250 [e1000e]
  ? kmem_cache_alloc+0x38/0x1c0
  tcf_classify+0x89/0x140
  __netif_receive_skb_core+0x5ea/0xb70
  ? enqueue_task_fair+0xb6/0x7d0
  ? process_backlog+0x97/0x150
  process_backlog+0x97/0x150
  net_rx_action+0x14b/0x3e0
  __do_softirq+0xde/0x2b4
  do_softirq_own_stack+0x2a/0x40
  </IRQ>
  do_softirq.part.18+0x49/0x50
  __local_bh_enable_ip+0x49/0x50
  __dev_queue_xmit+0x4ab/0x8a0
  ? wait_woken+0x80/0x80
  ? packet_sendmsg+0x38f/0x810
  ? __dev_queue_xmit+0x8a0/0x8a0
  packet_sendmsg+0x38f/0x810
  sock_sendmsg+0x36/0x40
  __sys_sendto+0x10e/0x140
  ? do_vfs_ioctl+0xa4/0x630
  ? syscall_trace_enter+0x1df/0x2e0
  ? __audit_syscall_exit+0x22a/0x290
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f5a45cbec93
 Code: 48 8b 0d 18 83 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c7 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 2b f7 ff ff 48 89 04 24
 RSP: 002b:00007ffd0ee6d748 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000001161010 RCX: 00007f5a45cbec93
 RDX: 0000000000000062 RSI: 0000000001161322 RDI: 0000000000000003
 RBP: 00007ffd0ee6d780 R08: 00007ffd0ee6d760 R09: 0000000000000014
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000062
 R13: 0000000001161322 R14: 00007ffd0ee6d760 R15: 0000000000000003
 Modules linked in: act_csum act_gact cls_flower sch_ingress vrf veth act_tunnel_key(E) xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_hdmi snd_hda_codec_realtek kvm snd_hda_codec_generic hp_wmi iTCO_wdt sparse_keymap rfkill mei_wdt iTCO_vendor_support wmi_bmof gpio_ich irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel snd_hda_intel crypto_simd cryptd snd_hda_codec glue_helper snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm pcspkr i2c_i801 snd_timer snd sg lpc_ich soundcore wmi mei_me
  mei ie31200_edac nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom sd_mod ahci libahci crc32c_intel i915 ixgbe serio_raw libata video dca i2c_algo_bit sfc drm_kms_helper syscopyarea mtd sysfillrect mdio sysimgblt fb_sys_fops drm e1000e i2c_core
 CR2: 0000000000000000
 ---[ end trace 3c9e9d1a77df4026 ]---
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffa020dea03c40 EFLAGS: 00010246
 RAX: 0000000020000001 RBX: ffffa020d7ccef00 RCX: 0000000000000054
 RDX: 0000000000000000 RSI: ffffa020ca5ae000 RDI: ffffa020d7ccef00
 RBP: ffffa020dea03e60 R08: 0000000000000000 R09: ffffa020dea03c9c
 R10: ffffa020dea03c78 R11: 0000000000000008 R12: ffffa020d3fe4f00
 R13: ffffa020d3fe4f08 R14: 0000000000000001 R15: ffffa020d53ca300
 FS:  00007f5a46942740(0000) GS:ffffa020dea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000104218002 CR4: 00000000001606f0
 Kernel panic - not syncing: Fatal exception in interrupt
 Kernel Offset: 0x26400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
 ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fixes: 9c5f69b ("net/sched: act_csum: don't use spinlock in the fast path")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
…used

the control action in the common member of struct tcf_tunnel_key must be a
valid value, as it can contain the chain index when 'goto chain' is used.
Ensure that the control action can be read as x->tcfa_action, when x is a
pointer to struct tc_action and x->ops->type is TCA_ACT_TUNNEL_KEY, to
prevent the following command:

 # tc filter add dev $h2 ingress protocol ip pref 1 handle 101 flower \
 > $tcflags dst_mac $h2mac action tunnel_key unset goto chain 1

from causing a NULL dereference when a matching packet is received:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 PGD 80000001097ac067 P4D 80000001097ac067 PUD 103b0a067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 3491 Comm: mausezahn Tainted: G            E     4.18.0-rc2.auguri+ torvalds#421
 Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.58 02/07/2013
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff95145ea03c40 EFLAGS: 00010246
 RAX: 0000000020000001 RBX: ffff9514499e5800 RCX: 0000000000000001
 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
 RBP: ffff95145ea03e60 R08: 0000000000000000 R09: ffff95145ea03c9c
 R10: ffff95145ea03c78 R11: 0000000000000008 R12: ffff951456a69800
 R13: ffff951456a69808 R14: 0000000000000001 R15: ffff95144965ee40
 FS:  00007fd67ee11740(0000) GS:ffff95145ea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001038a2006 CR4: 00000000001606f0
 Call Trace:
  <IRQ>
  fl_classify+0x1ad/0x1c0 [cls_flower]
  ? __update_load_avg_se.isra.47+0x1ca/0x1d0
  ? __update_load_avg_se.isra.47+0x1ca/0x1d0
  ? update_load_avg+0x665/0x690
  ? update_load_avg+0x665/0x690
  ? kmem_cache_alloc+0x38/0x1c0
  tcf_classify+0x89/0x140
  __netif_receive_skb_core+0x5ea/0xb70
  ? enqueue_entity+0xd0/0x270
  ? process_backlog+0x97/0x150
  process_backlog+0x97/0x150
  net_rx_action+0x14b/0x3e0
  __do_softirq+0xde/0x2b4
  do_softirq_own_stack+0x2a/0x40
  </IRQ>
  do_softirq.part.18+0x49/0x50
  __local_bh_enable_ip+0x49/0x50
  __dev_queue_xmit+0x4ab/0x8a0
  ? wait_woken+0x80/0x80
  ? packet_sendmsg+0x38f/0x810
  ? __dev_queue_xmit+0x8a0/0x8a0
  packet_sendmsg+0x38f/0x810
  sock_sendmsg+0x36/0x40
  __sys_sendto+0x10e/0x140
  ? do_vfs_ioctl+0xa4/0x630
  ? syscall_trace_enter+0x1df/0x2e0
  ? __audit_syscall_exit+0x22a/0x290
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fd67e18dc93
 Code: 48 8b 0d 18 83 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c7 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 2b f7 ff ff 48 89 04 24
 RSP: 002b:00007ffe0189b748 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 00000000020ca010 RCX: 00007fd67e18dc93
 RDX: 0000000000000062 RSI: 00000000020ca322 RDI: 0000000000000003
 RBP: 00007ffe0189b780 R08: 00007ffe0189b760 R09: 0000000000000014
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000062
 R13: 00000000020ca322 R14: 00007ffe0189b760 R15: 0000000000000003
 Modules linked in: act_tunnel_key act_gact cls_flower sch_ingress vrf veth act_csum(E) xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter intel_rapl snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp snd_hda_codec_realtek coretemp snd_hda_codec_generic kvm_intel kvm irqbypass snd_hda_intel crct10dif_pclmul crc32_pclmul hp_wmi ghash_clmulni_intel pcbc snd_hda_codec aesni_intel sparse_keymap rfkill snd_hda_core snd_hwdep snd_seq crypto_simd iTCO_wdt gpio_ich iTCO_vendor_support wmi_bmof cryptd mei_wdt glue_helper snd_seq_device snd_pcm pcspkr snd_timer snd i2c_i801 lpc_ich sg soundcore wmi mei_me
  mei ie31200_edac nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod sr_mod cdrom i915 video i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ahci crc32c_intel libahci serio_raw sfc libata mtd drm ixgbe mdio i2c_core e1000e dca
 CR2: 0000000000000000
 ---[ end trace 1ab8b5b5d4639dfc ]---
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff95145ea03c40 EFLAGS: 00010246
 RAX: 0000000020000001 RBX: ffff9514499e5800 RCX: 0000000000000001
 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
 RBP: ffff95145ea03e60 R08: 0000000000000000 R09: ffff95145ea03c9c
 R10: ffff95145ea03c78 R11: 0000000000000008 R12: ffff951456a69800
 R13: ffff951456a69808 R14: 0000000000000001 R15: ffff95144965ee40
 FS:  00007fd67ee11740(0000) GS:ffff95145ea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001038a2006 CR4: 00000000001606f0
 Kernel panic - not syncing: Fatal exception in interrupt
 Kernel Offset: 0x11400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
 ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fixes: d0f6dd8 ("net/sched: Introduce act_tunnel_key")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Aug 22, 2018
For the target_core_user use case, after the device is unregistered
it maybe still opened in user space, then the kernel will crash, like:

[  251.163692] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[  251.163820] IP: [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[  251.163965] PGD 8000000062694067 PUD 62696067 PMD 0
[  251.164097] Oops: 0000 [#1] SMP
...
[  251.165605]  e1000 mptscsih mptbase drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod
[  251.166014] CPU: 0 PID: 13380 Comm: tcmu-runner Kdump: loaded Not tainted 3.10.0-916.el7.test.x86_64 #1
[  251.166381] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[  251.166747] task: ffff971eb91db0c0 ti: ffff971e9e384000 task.ti: ffff971e9e384000
[  251.167137] RIP: 0010:[<ffffffffc0736213>]  [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[  251.167563] RSP: 0018:ffff971e9e387dc8  EFLAGS: 00010282
[  251.167978] RAX: 0000000000000000 RBX: ffff971e9e3f8000 RCX: ffff971eb8368d98
[  251.168408] RDX: ffff971e9e3f8000 RSI: ffffffffc0738084 RDI: ffff971e9e3f8000
[  251.168856] RBP: ffff971e9e387dd0 R08: ffff971eb8bc0018 R09: 0000000000000000
[  251.169296] R10: 0000000000001000 R11: ffffffffa09d444d R12: ffffffffa1076e80
[  251.169750] R13: ffff971e9e387f18 R14: 0000000000000001 R15: ffff971e9cfb1c80
[  251.170213] FS:  00007ff37d175880(0000) GS:ffff971ebb600000(0000) knlGS:0000000000000000
[  251.170693] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  251.171248] CR2: 0000000000000008 CR3: 00000000001f6000 CR4: 00000000003607f0
[  251.172071] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  251.172640] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  251.173236] Call Trace:
[  251.173789]  [<ffffffffa0c9b2d3>] dev_attr_show+0x23/0x60
[  251.174356]  [<ffffffffa0f561b2>] ? mutex_lock+0x12/0x2f
[  251.174892]  [<ffffffffa0ac6d9f>] sysfs_kf_seq_show+0xcf/0x1f0
[  251.175433]  [<ffffffffa0ac54e6>] kernfs_seq_show+0x26/0x30
[  251.175981]  [<ffffffffa0a63be0>] seq_read+0x110/0x3f0
[  251.176609]  [<ffffffffa0ac5d45>] kernfs_fop_read+0xf5/0x160
[  251.177158]  [<ffffffffa0a3d3af>] vfs_read+0x9f/0x170
[  251.177707]  [<ffffffffa0a3e27f>] SyS_read+0x7f/0xf0
[  251.178268]  [<ffffffffa0f648af>] system_call_fastpath+0x1c/0x21
[  251.178823] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 d3 e8 7e 96 56 e0 48 8b 80 d8 02 00 00 48 89 df 48 c7 c6 84 80 73 c0 <48> 8b 50 08 31 c0 e8 e2 67 44 e0 5b 48 98 5d c3 0f 1f 00 66 2e
[  251.180115] RIP  [<ffffffffc0736213>] show_name+0x23/0x40 [uio]
[  251.180820]  RSP <ffff971e9e387dc8>
[  251.181473] CR2: 0000000000000008

CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
CC: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
heikomat pushed a commit that referenced this issue Aug 22, 2018
rhashtable_free_and_destroy() cancels re-hash deferred work
then walks and destroys elements. at this moment, some elements can be
still in future_tbl. that elements are not destroyed.

test case:
nft_rhash_destroy() calls rhashtable_free_and_destroy() to destroy
all elements of sets before destroying sets and chains.
But rhashtable_free_and_destroy() doesn't destroy elements of future_tbl.
so that splat occurred.

test script:
   %cat test.nft
   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		}
	   }
	   chain a0 {
	   }
   }
   flush ruleset
   table ip aa {
	   map map1 {
		   type ipv4_addr : verdict;
		   elements = {
			   0 : jump a0,
			   1 : jump a0,
			   2 : jump a0,
			   3 : jump a0,
			   4 : jump a0,
			   5 : jump a0,
			   6 : jump a0,
			   7 : jump a0,
			   8 : jump a0,
			   9 : jump a0,
		   }
	   }
	   chain a0 {
	   }
   }
   flush ruleset

   %while :; do nft -f test.nft; done

Splat looks like:
[  200.795603] kernel BUG at net/netfilter/nf_tables_api.c:1363!
[  200.806944] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  200.812253] CPU: 1 PID: 1582 Comm: nft Not tainted 4.17.0+ torvalds#24
[  200.820297] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[  200.830309] RIP: 0010:nf_tables_chain_destroy.isra.34+0x62/0x240 [nf_tables]
[  200.838317] Code: 43 50 85 c0 74 26 48 8b 45 00 48 8b 4d 08 ba 54 05 00 00 48 c7 c6 60 6d 29 c0 48 c7 c7 c0 65 29 c0 4c 8b 40 08 e8 58 e5 fd f8 <0f> 0b 48 89 da 48 b8 00 00 00 00 00 fc ff
[  200.860366] RSP: 0000:ffff880118dbf4d0 EFLAGS: 00010282
[  200.866354] RAX: 0000000000000061 RBX: ffff88010cdeaf08 RCX: 0000000000000000
[  200.874355] RDX: 0000000000000061 RSI: 0000000000000008 RDI: ffffed00231b7e90
[  200.882361] RBP: ffff880118dbf4e8 R08: ffffed002373bcfb R09: ffffed002373bcfa
[  200.890354] R10: 0000000000000000 R11: ffffed002373bcfb R12: dead000000000200
[  200.898356] R13: dead000000000100 R14: ffffffffbb62af38 R15: dffffc0000000000
[  200.906354] FS:  00007fefc31fd700(0000) GS:ffff88011b800000(0000) knlGS:0000000000000000
[  200.915533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  200.922355] CR2: 0000557f1c8e9128 CR3: 0000000106880000 CR4: 00000000001006e0
[  200.930353] Call Trace:
[  200.932351]  ? nf_tables_commit+0x26f6/0x2c60 [nf_tables]
[  200.939525]  ? nf_tables_setelem_notify.constprop.49+0x1a0/0x1a0 [nf_tables]
[  200.947525]  ? nf_tables_delchain+0x6e0/0x6e0 [nf_tables]
[  200.952383]  ? nft_add_set_elem+0x1700/0x1700 [nf_tables]
[  200.959532]  ? nla_parse+0xab/0x230
[  200.963529]  ? nfnetlink_rcv_batch+0xd06/0x10d0 [nfnetlink]
[  200.968384]  ? nfnetlink_net_init+0x130/0x130 [nfnetlink]
[  200.975525]  ? debug_show_all_locks+0x290/0x290
[  200.980363]  ? debug_show_all_locks+0x290/0x290
[  200.986356]  ? sched_clock_cpu+0x132/0x170
[  200.990352]  ? find_held_lock+0x39/0x1b0
[  200.994355]  ? sched_clock_local+0x10d/0x130
[  200.999531]  ? memset+0x1f/0x40

V2:
 - free all tables requested by Herbert Xu

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue May 19, 2019
…esult

During the development of commit 5e1f0f0 ("mm, compaction: capture
a page under direct compaction"), a paranoid check was added to ensure
that if a captured page was available after compaction that it was
consistent with the final state of compaction.  The intent was to catch
serious programming bugs such as using a stale page pointer and causing
corruption problems.

However, it is possible to get a captured page even if compaction was
unsuccessful if an interrupt triggered and happened to free pages in
interrupt context that got merged into a suitable high-order page.  It's
highly unlikely but Li Wang did report the following warning on s390
occuring when testing OOM handling.  Note that the warning is slightly
edited for clarity.

  WARNING: CPU: 0 PID: 9783 at mm/page_alloc.c:3777 __alloc_pages_direct_compact+0x182/0x190
  Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs
    lockd grace fscache sunrpc pkey ghash_s390 prng xts aes_s390
    des_s390 des_generic sha512_s390 zcrypt_cex4 zcrypt vmur binfmt_misc
    ip_tables xfs libcrc32c dasd_fba_mod qeth_l2 dasd_eckd_mod dasd_mod
    qeth qdio lcs ctcm ccwgroup fsm dm_mirror dm_region_hash dm_log
    dm_mod
  CPU: 0 PID: 9783 Comm: copy.sh Kdump: loaded Not tainted 5.1.0-rc 5 #1

This patch simply removes the check entirely instead of trying to be
clever about pages freed from interrupt context.  If a serious
programming error was introduced, it is highly likely to be caught by
prep_new_page() instead.

Link: http://lkml.kernel.org/r/20190419085133.GH18914@techsingularity.net
Fixes: 5e1f0f0 ("mm, compaction: capture a page under direct compaction")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Li Wang <liwang@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue May 19, 2019
Syzkaller report this:

  sysctl could not get directory: /net//bridge -12
  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G         C        5.1.0-rc3+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
  RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline]
  RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline]
  RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline]
  RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459
  Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48
  RSP: 0018:ffff8881bb507778 EFLAGS: 00010206
  RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a
  RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568
  RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4
  R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558
  R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   erase_entry fs/proc/proc_sysctl.c:178 [inline]
   erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207
   start_unregistering fs/proc/proc_sysctl.c:331 [inline]
   drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631
   get_subdir fs/proc/proc_sysctl.c:1022 [inline]
   __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335
   br_netfilter_init+0x68/0x1000 [br_netfilter]
   do_one_initcall+0xbc/0x47d init/main.c:901
   do_init_module+0x1b5/0x547 kernel/module.c:3456
   load_module+0x6405/0x8c10 kernel/module.c:3804
   __do_sys_finit_module+0x162/0x190 kernel/module.c:3898
   do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle
   iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter]
  Dumping ftrace buffer:
     (ftrace buffer empty)
  ---[ end trace 68741688d5fbfe85 ]---

commit 23da958 ("fs/proc/proc_sysctl.c: fix NULL pointer
dereference in put_links") forgot to handle start_unregistering() case,
while header->parent is NULL, it calls erase_header() and as seen in the
above syzkaller call trace, accessing &header->parent->root will trigger
a NULL pointer dereference.

As that commit explained, there is also no need to call
start_unregistering() if header->parent is NULL.

Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com
Fixes: 23da958 ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links")
Fixes: 0e47c99 ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue May 19, 2019
We don't check for the validity of the lengths in the packet received
from the firmware.  If the MPDU length received in the rx descriptor
is too short to contain the header length and the crypt length
together, we may end up trying to copy a negative number of bytes
(headlen - hdrlen < 0) which will underflow and cause us to try to
copy a huge amount of data.  This causes oopses such as this one:

BUG: unable to handle kernel paging request at ffff896be2970000
PGD 5e201067 P4D 5e201067 PUD 5e205067 PMD 16110d063 PTE 8000000162970161
Oops: 0003 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 1824 Comm: irq/134-iwlwifi Not tainted 4.19.33-04308-geea41cf4930f #1
Hardware name: [...]
RIP: 0010:memcpy_erms+0x6/0x10
Code: 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3
 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe
RSP: 0018:ffffa4630196fc60 EFLAGS: 00010287
RAX: ffff896be2924618 RBX: ffff896bc8ecc600 RCX: 00000000fffb4610
RDX: 00000000fffffff8 RSI: ffff896a835e2a38 RDI: ffff896be2970000
RBP: ffffa4630196fd30 R08: ffff896bc8ecc600 R09: ffff896a83597000
R10: ffff896bd6998400 R11: 000000000200407f R12: ffff896a83597050
R13: 00000000fffffff8 R14: 0000000000000010 R15: ffff896a83597038
FS:  0000000000000000(0000) GS:ffff896be8280000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff896be2970000 CR3: 000000005dc12002 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 iwl_mvm_rx_mpdu_mq+0xb51/0x121b [iwlmvm]
 iwl_pcie_rx_handle+0x58c/0xa89 [iwlwifi]
 iwl_pcie_irq_rx_msix_handler+0xd9/0x12a [iwlwifi]
 irq_thread_fn+0x24/0x49
 irq_thread+0xb0/0x122
 kthread+0x138/0x140
 ret_from_fork+0x1f/0x40

Fix that by checking the lengths for correctness and trigger a warning
to show that we have received wrong data.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
heikomat pushed a commit that referenced this issue May 19, 2019
If io_allocate_scq_urings() fails to allocate an sq_* region, it will
call io_mem_free() for any previously allocated regions, but leave
dangling pointers to these regions in the ctx. Any regions which have
not yet been allocated are left NULL. Note that when returning
-EOVERFLOW, the previously allocated sq_ring is not freed, which appears
to be an unintentional leak.

When io_allocate_scq_urings() fails, io_uring_create() will call
io_ring_ctx_wait_and_kill(), which calls io_mem_free() on all the sq_*
regions, assuming the pointers are valid and not NULL.

This can result in pages being freed multiple times, which has been
observed to corrupt the page state, leading to subsequent fun. This can
also result in virt_to_page() on NULL, resulting in the use of bogus
page addresses, and yet more subsequent fun. The latter can be detected
with CONFIG_DEBUG_VIRTUAL on arm64.

Adding a cleanup path to io_allocate_scq_urings() complicates the logic,
so let's leave it to io_ring_ctx_free() to consistently free these
pointers, and simplify the io_allocate_scq_urings() error paths.

Full splats from before this patch below. Note that the pointer logged
by the DEBUG_VIRTUAL "non-linear address" warning has been hashed, and
is actually NULL.

[   26.098129] page:ffff80000e949a00 count:0 mapcount:-128 mapping:0000000000000000 index:0x0
[   26.102976] flags: 0x63fffc000000()
[   26.104373] raw: 000063fffc000000 ffff80000e86c188 ffff80000ea3df08 0000000000000000
[   26.108917] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
[   26.137235] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
[   26.143960] ------------[ cut here ]------------
[   26.146020] kernel BUG at include/linux/mm.h:547!
[   26.147586] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[   26.149163] Modules linked in:
[   26.150287] Process syz-executor.21 (pid: 20204, stack limit = 0x000000000e9cefeb)
[   26.153307] CPU: 2 PID: 20204 Comm: syz-executor.21 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 torvalds#18
[   26.156566] Hardware name: linux,dummy-virt (DT)
[   26.158089] pstate: 40400005 (nZcv daif +PAN -UAO)
[   26.159869] pc : io_mem_free+0x9c/0xa8
[   26.161436] lr : io_mem_free+0x9c/0xa8
[   26.162720] sp : ffff000013003d60
[   26.164048] x29: ffff000013003d60 x28: ffff800025048040
[   26.165804] x27: 0000000000000000 x26: ffff800025048040
[   26.167352] x25: 00000000000000c0 x24: ffff0000112c2820
[   26.169682] x23: 0000000000000000 x22: 0000000020000080
[   26.171899] x21: ffff80002143b418 x20: ffff80002143b400
[   26.174236] x19: ffff80002143b280 x18: 0000000000000000
[   26.176607] x17: 0000000000000000 x16: 0000000000000000
[   26.178997] x15: 0000000000000000 x14: 0000000000000000
[   26.181508] x13: 00009178a5e077b2 x12: 0000000000000001
[   26.183863] x11: 0000000000000000 x10: 0000000000000980
[   26.186437] x9 : ffff000013003a80 x8 : ffff800025048a20
[   26.189006] x7 : ffff8000250481c0 x6 : ffff80002ffe9118
[   26.191359] x5 : ffff80002ffe9118 x4 : 0000000000000000
[   26.193863] x3 : ffff80002ffefe98 x2 : 44c06ddd107d1f00
[   26.196642] x1 : 0000000000000000 x0 : 000000000000003e
[   26.198892] Call trace:
[   26.199893]  io_mem_free+0x9c/0xa8
[   26.201155]  io_ring_ctx_wait_and_kill+0xec/0x180
[   26.202688]  io_uring_setup+0x6c4/0x6f0
[   26.204091]  __arm64_sys_io_uring_setup+0x18/0x20
[   26.205576]  el0_svc_common.constprop.0+0x7c/0xe8
[   26.207186]  el0_svc_handler+0x28/0x78
[   26.208389]  el0_svc+0x8/0xc
[   26.209408] Code: aa0203e0 d0006861 9133a021 97fcdc3c (d4210000)
[   26.211995] ---[ end trace bdb81cd43a21e50d ]---

[   81.770626] ------------[ cut here ]------------
[   81.825015] virt_to_phys used for non-linear address: 000000000d42f2c7 (          (null))
[   81.827860] WARNING: CPU: 1 PID: 30171 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x48/0x68
[   81.831202] Modules linked in:
[   81.832212] CPU: 1 PID: 30171 Comm: syz-executor.20 Not tainted 5.1.0-rc7-00004-g7d30b2ea43d6 torvalds#19
[   81.835616] Hardware name: linux,dummy-virt (DT)
[   81.836863] pstate: 60400005 (nZCv daif +PAN -UAO)
[   81.838727] pc : __virt_to_phys+0x48/0x68
[   81.840572] lr : __virt_to_phys+0x48/0x68
[   81.842264] sp : ffff80002cf67c70
[   81.843858] x29: ffff80002cf67c70 x28: ffff800014358e18
[   81.846463] x27: 0000000000000000 x26: 0000000020000080
[   81.849148] x25: 0000000000000000 x24: ffff80001bb01f40
[   81.851986] x23: ffff200011db06c8 x22: ffff2000127e3c60
[   81.854351] x21: ffff800014358cc0 x20: ffff800014358d98
[   81.856711] x19: 0000000000000000 x18: 0000000000000000
[   81.859132] x17: 0000000000000000 x16: 0000000000000000
[   81.861586] x15: 0000000000000000 x14: 0000000000000000
[   81.863905] x13: 0000000000000000 x12: ffff1000037603e9
[   81.866226] x11: 1ffff000037603e8 x10: 0000000000000980
[   81.868776] x9 : ffff80002cf67840 x8 : ffff80001bb02920
[   81.873272] x7 : ffff1000037603e9 x6 : ffff80001bb01f47
[   81.875266] x5 : ffff1000037603e9 x4 : dfff200000000000
[   81.876875] x3 : ffff200010087528 x2 : ffff1000059ecf58
[   81.878751] x1 : 44c06ddd107d1f00 x0 : 0000000000000000
[   81.880453] Call trace:
[   81.881164]  __virt_to_phys+0x48/0x68
[   81.882919]  io_mem_free+0x18/0x110
[   81.886585]  io_ring_ctx_wait_and_kill+0x13c/0x1f0
[   81.891212]  io_uring_setup+0xa60/0xad0
[   81.892881]  __arm64_sys_io_uring_setup+0x2c/0x38
[   81.894398]  el0_svc_common.constprop.0+0xac/0x150
[   81.896306]  el0_svc_handler+0x34/0x88
[   81.897744]  el0_svc+0x8/0xc
[   81.898715] ---[ end trace b4a703802243cbba ]---

Fixes: 2b188cc ("Add io_uring IO interface")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
heikomat pushed a commit that referenced this issue May 22, 2019
Architectures like ppc64 use the deposited page table to store hardware
page table slot information. Make sure we deposit a page table when
using zero page at the pmd level for hash.

Without this we hit

Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000082a74
Oops: Kernel access of bad area, sig: 11 [#1]
....

NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0
LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0
Call Trace:
 hash_page_mm+0x43c/0x740
 do_hash_page+0x2c/0x3c
 copy_from_iter_flushcache+0xa4/0x4a0
 pmem_copy_from_iter+0x2c/0x50 [nd_pmem]
 dax_copy_from_iter+0x40/0x70
 dax_iomap_actor+0x134/0x360
 iomap_apply+0xfc/0x1b0
 dax_iomap_rw+0xac/0x130
 ext4_file_write_iter+0x254/0x460 [ext4]
 __vfs_write+0x120/0x1e0
 vfs_write+0xd8/0x220
 SyS_write+0x6c/0x110
 system_call+0x3c/0x130

Fixes: b5beae5 ("powerpc/pseries: Add driver for PAPR SCM regions")
Cc: <stable@vger.kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
heikomat pushed a commit that referenced this issue May 22, 2019
If codec registration fails after the ASoC Intel SST driver has been probed,
the kernel will Oops and crash at suspend/resume.

general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 2811 Comm: cat Tainted: G        W         4.19.30 torvalds#15
Hardware name: GOOGLE Clapper, BIOS Google_Clapper.5216.199.7 08/22/2014
RIP: 0010:snd_soc_suspend+0x5a/0xd21
Code: 03 80 3c 10 00 49 89 d7 74 0b 48 89 df e8 71 72 c4 fe 4c 89
fa 48 8b 03 48 89 45 d0 48 8d 98 a0 01 00 00 48 89 d8 48 c1 e8 03
<8a> 04 10 84 c0 0f 85 85 0c 00 00 80 3b 00 0f 84 6b 0c 00 00 48 8b
RSP: 0018:ffff888035407750 EFLAGS: 00010202
RAX: 0000000000000034 RBX: 00000000000001a0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88805c417098
RBP: ffff8880354077b0 R08: dffffc0000000000 R09: ffffed100b975718
R10: 0000000000000001 R11: ffffffff949ea4a3 R12: 1ffff1100b975746
R13: dffffc0000000000 R14: ffff88805cba4588 R15: dffffc0000000000
FS:  0000794a78e91b80(0000) GS:ffff888068d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007bd5283ccf58 CR3: 000000004b7aa000 CR4: 00000000001006e0
Call Trace:
? dpm_complete+0x67b/0x67b
? i915_gem_suspend+0x14d/0x1ad
sst_soc_prepare+0x91/0x1dd
? sst_be_hw_params+0x7e/0x7e
dpm_prepare+0x39a/0x88b
dpm_suspend_start+0x13/0x9d
suspend_devices_and_enter+0x18f/0xbd7
? arch_suspend_enable_irqs+0x11/0x11
? printk+0xd9/0x12d
? lock_release+0x95f/0x95f
? log_buf_vmcoreinfo_setup+0x131/0x131
? rcu_read_lock_sched_held+0x140/0x22a
? __bpf_trace_rcu_utilization+0xa/0xa
? __pm_pr_dbg+0x186/0x190
? pm_notifier_call_chain+0x39/0x39
? suspend_test+0x9d/0x9d
pm_suspend+0x2f4/0x728
? trace_suspend_resume+0x3da/0x3da
? lock_release+0x95f/0x95f
? kernfs_fop_write+0x19f/0x32d
state_store+0xd8/0x147
? sysfs_kf_read+0x155/0x155
kernfs_fop_write+0x23e/0x32d
__vfs_write+0x108/0x608
? vfs_read+0x2e9/0x2e9
? rcu_read_lock_sched_held+0x140/0x22a
? __bpf_trace_rcu_utilization+0xa/0xa
? debug_smp_processor_id+0x10/0x10
? selinux_file_permission+0x1c5/0x3c8
? rcu_sync_lockdep_assert+0x6a/0xad
? __sb_start_write+0x129/0x2ac
vfs_write+0x1aa/0x434
ksys_write+0xfe/0x1be
? __ia32_sys_read+0x82/0x82
do_syscall_64+0xcd/0x120
entry_SYSCALL_64_after_hwframe+0x49/0xbe

In the observed situation, the problem is seen because the codec driver
failed to probe due to a hardware problem.

max98090 i2c-193C9890:00: Failed to read device revision: -1
max98090 i2c-193C9890:00: ASoC: failed to probe component -1
cht-bsw-max98090 cht-bsw-max98090: ASoC: failed to instantiate card -1
cht-bsw-max98090 cht-bsw-max98090: snd_soc_register_card failed -1
cht-bsw-max98090: probe of cht-bsw-max98090 failed with error -1

The problem is similar to the problem solved with commit 2fc995a
("ASoC: intel: Fix crash at suspend/resume without card registration"),
but codec registration fails at a later point. At that time, the pointer
checked with the above mentioned commit is already set, but it is not
cleared if the device is subsequently removed. Adding a remove function
to clear the pointer fixes the problem.

Cc: stable@vger.kernel.org
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Curtis Malainey <cujomalainey@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
heikomat pushed a commit that referenced this issue May 22, 2019
This fixes a possible circular locking dependency detected warning seen
with:
- CONFIG_PROVE_LOCKING=y
- consumer/provider IIO devices (ex: "voltage-divider" consumer of "adc")

When using the IIO consumer interface, e.g. iio_channel_get(), the consumer
device will likely call iio_read_channel_raw() or similar that rely on
'info_exist_lock' mutex.

typically:
...
	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}
	ret = do_some_ops()
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);
	return ret;
...

Same mutex is also hold in iio_device_unregister().

The following deadlock warning happens when:
- the consumer device has called an API like iio_read_channel_raw()
  at least once.
- the consumer driver is unregistered, removed (unbind from sysfs)

======================================================
WARNING: possible circular locking dependency detected
4.19.24 torvalds#577 Not tainted
------------------------------------------------------
sh/372 is trying to acquire lock:
(kn->count#30){++++}, at: kernfs_remove_by_name_ns+0x3c/0x84

but task is already holding lock:
(&dev->info_exist_lock){+.+.}, at: iio_device_unregister+0x18/0x60

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&dev->info_exist_lock){+.+.}:
       __mutex_lock+0x70/0xa3c
       mutex_lock_nested+0x1c/0x24
       iio_read_channel_raw+0x1c/0x60
       iio_read_channel_info+0xa8/0xb0
       dev_attr_show+0x1c/0x48
       sysfs_kf_seq_show+0x84/0xec
       seq_read+0x154/0x528
       __vfs_read+0x2c/0x15c
       vfs_read+0x8c/0x110
       ksys_read+0x4c/0xac
       ret_fast_syscall+0x0/0x28
       0xbedefb60

-> #0 (kn->count#30){++++}:
       lock_acquire+0xd8/0x268
       __kernfs_remove+0x288/0x374
       kernfs_remove_by_name_ns+0x3c/0x84
       remove_files+0x34/0x78
       sysfs_remove_group+0x40/0x9c
       sysfs_remove_groups+0x24/0x34
       device_remove_attrs+0x38/0x64
       device_del+0x11c/0x360
       cdev_device_del+0x14/0x2c
       iio_device_unregister+0x24/0x60
       release_nodes+0x1bc/0x200
       device_release_driver_internal+0x1a0/0x230
       unbind_store+0x80/0x130
       kernfs_fop_write+0x100/0x1e4
       __vfs_write+0x2c/0x160
       vfs_write+0xa4/0x17c
       ksys_write+0x4c/0xac
       ret_fast_syscall+0x0/0x28
       0xbe906840

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dev->info_exist_lock);
                               lock(kn->count#30);
                               lock(&dev->info_exist_lock);
  lock(kn->count#30);

 *** DEADLOCK ***
...

cdev_device_del() can be called without holding the lock. It should be safe
as info_exist_lock prevents kernelspace consumers to use the exported
routines during/after provider removal. cdev_device_del() is for userspace.

Help to reproduce:
See example: Documentation/devicetree/bindings/iio/afe/voltage-divider.txt
sysv {
	compatible = "voltage-divider";
	io-channels = <&adc 0>;
	output-ohms = <22>;
	full-ohms = <222>;
};

First, go to iio:deviceX for the "voltage-divider", do one read:
$ cd /sys/bus/iio/devices/iio:deviceX
$ cat in_voltage0_raw

Then, unbind the consumer driver. It triggers above deadlock warning.
$ cd /sys/bus/platform/drivers/iio-rescale/
$ echo sysv > unbind

Note I don't actually expect stable will pick this up all the
way back into IIO being in staging, but if's probably valid that
far back.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Fixes: ac917a8 ("staging:iio:core set the iio_dev.info pointer to null on unregister")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Commit 87fd125 ("nvme-rdma: remove redundant reference between
ib_device and tagset") caused a kernel panic when disconnecting from an
inaccessible controller (disconnect during re-connection).

--
nvme nvme0: Removing ctrl: NQN "testnqn1"
nvme_rdma: nvme_rdma_exit_request: hctx 0 queue_idx 1
BUG: unable to handle kernel paging request at 0000000080000228
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
...
Call Trace:
 blk_mq_exit_hctx+0x5c/0xf0
 blk_mq_exit_queue+0xd4/0x100
 blk_cleanup_queue+0x9a/0xc0
 nvme_rdma_destroy_io_queues+0x52/0x60 [nvme_rdma]
 nvme_rdma_shutdown_ctrl+0x3e/0x80 [nvme_rdma]
 nvme_do_delete_ctrl+0x53/0x80 [nvme_core]
 nvme_sysfs_delete+0x45/0x60 [nvme_core]
 kernfs_fop_write+0x105/0x180
 vfs_write+0xad/0x1a0
 ksys_write+0x5a/0xd0
 do_syscall_64+0x55/0x110
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fa215417154
--

The reason for this crash is accessing an already freed ib_device for
performing dma_unmap during exit_request commands. The root cause for
that is that during re-connection all the queues are destroyed and
re-created (and the ib_device is reference counted by the queues and
freed as well) but the tagset stays alive and all the DMA mappings (that
we perform in init_request) kept in the request context. The original
commit fixed a different bug that was introduced during bonding (aka nic
teaming) tests that for some scenarios change the underlying ib_device
and caused memory leakage and possible segmentation fault. This commit
is a complementary commit that also changes the wrong DMA mappings that
were saved in the request context and making the request sqe dma
mappings dynamic with the command lifetime (i.e. mapped in .queue_rq and
unmapped in .complete). It also fixes the above crash of accessing freed
ib_device during destruction of the tagset.

Fixes: 87fd125 ("nvme-rdma: remove redundant reference between ib_device and tagset")
Reported-by: Jim Harris <james.r.harris@intel.com>
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
heikomat pushed a commit that referenced this issue Jul 13, 2019
In following sequences, child devices created while removing mdev parent
device can be left out, or it may lead to race of removing half
initialized child mdev devices.

issue-1:
--------
       cpu-0                         cpu-1
       -----                         -----
                                  mdev_unregister_device()
                                    device_for_each_child()
                                      mdev_device_remove_cb()
                                        mdev_device_remove()
create_store()
  mdev_device_create()                   [...]
    device_add()
                                  parent_remove_sysfs_files()

/* BUG: device added by cpu-0
 * whose parent is getting removed
 * and it won't process this mdev.
 */

issue-2:
--------
Below crash is observed when user initiated remove is in progress
and mdev_unregister_driver() completes parent unregistration.

       cpu-0                         cpu-1
       -----                         -----
remove_store()
   mdev_device_remove()
   active = false;
                                  mdev_unregister_device()
                                  parent device removed.
   [...]
   parents->ops->remove()
 /*
  * BUG: Accessing invalid parent.
  */

This is similar race like create() racing with mdev_unregister_device().

BUG: unable to handle kernel paging request at ffffffffc0585668
PGD e8f618067 P4D e8f618067 PUD e8f61a067 PMD 85adca067 PTE 0
Oops: 0000 [#1] SMP PTI
CPU: 41 PID: 37403 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
RIP: 0010:mdev_device_remove+0xfa/0x140 [mdev]
Call Trace:
 remove_store+0x71/0x90 [mdev]
 kernfs_fop_write+0x113/0x1a0
 vfs_write+0xad/0x1b0
 ksys_write+0x5a/0xe0
 do_syscall_64+0x5a/0x210
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Therefore, mdev core is improved as below to overcome above issues.

Wait for any ongoing mdev create() and remove() to finish before
unregistering parent device.
This continues to allow multiple create and remove to progress in
parallel for different mdev devices as most common case.
At the same time guard parent removal while parent is being accessed by
create() and remove() callbacks.
create()/remove() and unregister_device() are synchronized by the rwsem.

Refactor device removal code to mdev_device_remove_common() to avoid
acquiring unreg_sem of the parent.

Fixes: 7b96953 ("vfio: Mediated device Core driver")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
In order to create an internal vport, internal_dev_create() is used and
that calls register_netdevice() internally.
If register_netdevice() fails, it calls dev->priv_destructor() to free
private data of netdev. actually, a private data of this is a vport.

Hence internal_dev_create() should not free and use a vport after failure
of register_netdevice().

Test command
    ovs-dpctl add-dp bonding_masters

Splat looks like:
[ 1035.667767] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 1035.675958] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1035.676916] CPU: 1 PID: 1028 Comm: ovs-vswitchd Tainted: G    B             5.2.0-rc3+ torvalds#240
[ 1035.676916] RIP: 0010:internal_dev_create+0x2e5/0x4e0 [openvswitch]
[ 1035.676916] Code: 48 c1 ea 03 80 3c 02 00 0f 85 9f 01 00 00 4c 8b 23 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 60 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 86 01 00 00 49 8b bc 24 60 05 00 00 e8 e4 68 f4
[ 1035.713720] RSP: 0018:ffff88810dcb7578 EFLAGS: 00010206
[ 1035.713720] RAX: dffffc0000000000 RBX: ffff88810d13fe08 RCX: ffffffff84297704
[ 1035.713720] RDX: 00000000000000ac RSI: 0000000000000000 RDI: 0000000000000560
[ 1035.713720] RBP: 00000000ffffffef R08: fffffbfff0d3b881 R09: fffffbfff0d3b881
[ 1035.713720] R10: 0000000000000001 R11: fffffbfff0d3b880 R12: 0000000000000000
[ 1035.768776] R13: 0000607ee460b900 R14: ffff88810dcb7690 R15: ffff88810dcb7698
[ 1035.777709] FS:  00007f02095fc980(0000) GS:ffff88811b400000(0000) knlGS:0000000000000000
[ 1035.777709] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1035.777709] CR2: 00007ffdf01d2f28 CR3: 0000000108258000 CR4: 00000000001006e0
[ 1035.777709] Call Trace:
[ 1035.777709]  ovs_vport_add+0x267/0x4f0 [openvswitch]
[ 1035.777709]  new_vport+0x15/0x1e0 [openvswitch]
[ 1035.777709]  ovs_vport_cmd_new+0x567/0xd10 [openvswitch]
[ 1035.777709]  ? ovs_dp_cmd_dump+0x490/0x490 [openvswitch]
[ 1035.777709]  ? __kmalloc+0x131/0x2e0
[ 1035.777709]  ? genl_family_rcv_msg+0xa54/0x1030
[ 1035.777709]  genl_family_rcv_msg+0x63a/0x1030
[ 1035.777709]  ? genl_unregister_family+0x630/0x630
[ 1035.841681]  ? debug_show_all_locks+0x2d0/0x2d0
[ ... ]

Fixes: cf124db ("net: Fix inconsistent teardown and release of private netdev state.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Jul 13, 2019
The qp priv rcd pointer doesn't match the context being used for verbs
causing issues when 9B and kdeth packets are processed by different
receive contexts and hence different CPUs.

When running on different CPUs the following panic can occur:

 WARNING: CPU: 3 PID: 2584 at lib/list_debug.c:59 __list_del_entry+0xa1/0xd0
 list_del corruption. prev->next should be ffff9a7ac31f7a30, but was ffff9a7c3bc89230
 CPU: 3 PID: 2584 Comm: z_wr_iss Kdump: loaded Tainted: P           OE  ------------   3.10.0-862.2.3.el7_lustre.x86_64 #1
 Call Trace:
  <IRQ>  [<ffffffffb7b0d78e>] dump_stack+0x19/0x1b
  [<ffffffffb74916d8>] __warn+0xd8/0x100
  [<ffffffffb749175f>] warn_slowpath_fmt+0x5f/0x80
  [<ffffffffb7768671>] __list_del_entry+0xa1/0xd0
  [<ffffffffc0c7a945>] process_rcv_qp_work+0xb5/0x160 [hfi1]
  [<ffffffffc0c7bc2b>] handle_receive_interrupt_nodma_rtail+0x20b/0x2b0 [hfi1]
  [<ffffffffc0c70683>] receive_context_interrupt+0x23/0x40 [hfi1]
  [<ffffffffb7540a94>] __handle_irq_event_percpu+0x44/0x1c0
  [<ffffffffb7540c42>] handle_irq_event_percpu+0x32/0x80
  [<ffffffffb7540ccc>] handle_irq_event+0x3c/0x60
  [<ffffffffb7543a1f>] handle_edge_irq+0x7f/0x150
  [<ffffffffb742d504>] handle_irq+0xe4/0x1a0
  [<ffffffffb7b23f7d>] do_IRQ+0x4d/0xf0
  [<ffffffffb7b16362>] common_interrupt+0x162/0x162
  <EOI>  [<ffffffffb775a326>] ? memcpy+0x6/0x110
  [<ffffffffc109210d>] ? abd_copy_from_buf_off_cb+0x1d/0x30 [zfs]
  [<ffffffffc10920f0>] ? abd_copy_to_buf_off_cb+0x30/0x30 [zfs]
  [<ffffffffc1093257>] abd_iterate_func+0x97/0x120 [zfs]
  [<ffffffffc10934d9>] abd_copy_from_buf_off+0x39/0x60 [zfs]
  [<ffffffffc109b828>] arc_write_ready+0x178/0x300 [zfs]
  [<ffffffffb7b11032>] ? mutex_lock+0x12/0x2f
  [<ffffffffb7b11032>] ? mutex_lock+0x12/0x2f
  [<ffffffffc1164d05>] zio_ready+0x65/0x3d0 [zfs]
  [<ffffffffc04d725e>] ? tsd_get_by_thread+0x2e/0x50 [spl]
  [<ffffffffc04d1318>] ? taskq_member+0x18/0x30 [spl]
  [<ffffffffc115ef22>] zio_execute+0xa2/0x100 [zfs]
  [<ffffffffc04d1d2c>] taskq_thread+0x2ac/0x4f0 [spl]
  [<ffffffffb74cee80>] ? wake_up_state+0x20/0x20
  [<ffffffffc115ee80>] ? zio_taskq_member.isra.7.constprop.10+0x80/0x80 [zfs]
  [<ffffffffc04d1a80>] ? taskq_thread_spawn+0x60/0x60 [spl]
  [<ffffffffb74bae31>] kthread+0xd1/0xe0
  [<ffffffffb74bad60>] ? insert_kthread_work+0x40/0x40
  [<ffffffffb7b1f5f7>] ret_from_fork_nospec_begin+0x21/0x21
  [<ffffffffb74bad60>] ? insert_kthread_work+0x40/0x40

Fix by reading the map entry in the same manner as the hardware so that
the kdeth and verbs contexts match.

Cc: <stable@vger.kernel.org>
Fixes: 5190f05 ("IB/hfi1: Allow the driver to initialize QP priv struct")
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Booting with kernel parameter "rdt=cmt,mbmtotal,memlocal,l3cat,mba" and
executing "mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl" results in
a NULL pointer dereference on systems which do not have local MBM support
enabled..

BUG: kernel NULL pointer dereference, address: 0000000000000020
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 722 Comm: kworker/0:3 Not tainted 5.2.0-0.rc3.git0.1.el7_UNSUPPORTED.x86_64 #2
Workqueue: events mbm_handle_overflow
RIP: 0010:mbm_handle_overflow+0x150/0x2b0

Only enter the bandwith update loop if the system has local MBM enabled.

Fixes: de73f38 ("x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190610171544.13474-1-prarit@redhat.com
heikomat pushed a commit that referenced this issue Jul 13, 2019
If a task is removing the block group that currently has the highest start
offset amongst all existing block groups, there is a short time window
where it races with a concurrent block group allocation, resulting in a
transaction abort with an error code of EEXIST.

The following diagram explains the race in detail:

      Task A                                                        Task B

 btrfs_remove_block_group(bg offset X)

   remove_extent_mapping(em offset X)
     -> removes extent map X from the
        tree of extent maps
        (fs_info->mapping_tree), so the
        next call to find_next_chunk()
        will return offset X

                                                   btrfs_alloc_chunk()
                                                     find_next_chunk()
                                                       --> returns offset X

                                                     __btrfs_alloc_chunk(offset X)
                                                       btrfs_make_block_group()
                                                         btrfs_create_block_group_cache()
                                                           --> creates btrfs_block_group_cache
                                                               object with a key corresponding
                                                               to the block group item in the
                                                               extent, the key is:
                                                               (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)

                                                         --> adds the btrfs_block_group_cache object
                                                             to the list new_bgs of the transaction
                                                             handle

                                                   btrfs_end_transaction(trans handle)
                                                     __btrfs_end_transaction()
                                                       btrfs_create_pending_block_groups()
                                                         --> sees the new btrfs_block_group_cache
                                                             in the new_bgs list of the transaction
                                                             handle
                                                         --> its call to btrfs_insert_item() fails
                                                             with -EEXIST when attempting to insert
                                                             the block group item key
                                                             (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)
                                                             because task A has not removed that key yet
                                                         --> aborts the running transaction with
                                                             error -EEXIST

   btrfs_del_item()
     -> removes the block group's key from
        the extent tree, key is
        (offset X, BTRFS_BLOCK_GROUP_ITEM_KEY, 1G)

A sample transaction abort trace:

  [78912.403537] ------------[ cut here ]------------
  [78912.403811] BTRFS: Transaction aborted (error -17)
  [78912.404082] WARNING: CPU: 2 PID: 20465 at fs/btrfs/extent-tree.c:10551 btrfs_create_pending_block_groups+0x196/0x250 [btrfs]
  (...)
  [78912.405642] CPU: 2 PID: 20465 Comm: btrfs Tainted: G        W         5.0.0-btrfs-next-46 #1
  [78912.405941] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
  [78912.406586] RIP: 0010:btrfs_create_pending_block_groups+0x196/0x250 [btrfs]
  (...)
  [78912.407636] RSP: 0018:ffff9d3d4b7e3b08 EFLAGS: 00010282
  [78912.407997] RAX: 0000000000000000 RBX: ffff90959a3796f0 RCX: 0000000000000006
  [78912.408369] RDX: 0000000000000007 RSI: 0000000000000001 RDI: ffff909636b16860
  [78912.408746] RBP: ffff909626758a58 R08: 0000000000000000 R09: 0000000000000000
  [78912.409144] R10: ffff9095ff462400 R11: 0000000000000000 R12: ffff90959a379588
  [78912.409521] R13: ffff909626758ab0 R14: ffff9095036c0000 R15: ffff9095299e1158
  [78912.409899] FS:  00007f387f16f700(0000) GS:ffff909636b00000(0000) knlGS:0000000000000000
  [78912.410285] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [78912.410673] CR2: 00007f429fc87cbc CR3: 000000014440a004 CR4: 00000000003606e0
  [78912.411095] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [78912.411496] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [78912.411898] Call Trace:
  [78912.412318]  __btrfs_end_transaction+0x5b/0x1c0 [btrfs]
  [78912.412746]  btrfs_inc_block_group_ro+0xcf/0x160 [btrfs]
  [78912.413179]  scrub_enumerate_chunks+0x188/0x5b0 [btrfs]
  [78912.413622]  ? __mutex_unlock_slowpath+0x100/0x2a0
  [78912.414078]  btrfs_scrub_dev+0x2ef/0x720 [btrfs]
  [78912.414535]  ? __sb_start_write+0xd4/0x1c0
  [78912.414963]  ? mnt_want_write_file+0x24/0x50
  [78912.415403]  btrfs_ioctl+0x17fb/0x3120 [btrfs]
  [78912.415832]  ? lock_acquire+0xa6/0x190
  [78912.416256]  ? do_vfs_ioctl+0xa2/0x6f0
  [78912.416685]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
  [78912.417116]  do_vfs_ioctl+0xa2/0x6f0
  [78912.417534]  ? __fget+0x113/0x200
  [78912.417954]  ksys_ioctl+0x70/0x80
  [78912.418369]  __x64_sys_ioctl+0x16/0x20
  [78912.418812]  do_syscall_64+0x60/0x1b0
  [78912.419231]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [78912.419644] RIP: 0033:0x7f3880252dd7
  (...)
  [78912.420957] RSP: 002b:00007f387f16ed68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [78912.421426] RAX: ffffffffffffffda RBX: 000055f5becc1df0 RCX: 00007f3880252dd7
  [78912.421889] RDX: 000055f5becc1df0 RSI: 00000000c400941b RDI: 0000000000000003
  [78912.422354] RBP: 0000000000000000 R08: 00007f387f16f700 R09: 0000000000000000
  [78912.422790] R10: 00007f387f16f700 R11: 0000000000000246 R12: 0000000000000000
  [78912.423202] R13: 00007ffda49c266f R14: 0000000000000000 R15: 00007f388145e040
  [78912.425505] ---[ end trace eb9bfe7c426fc4d3 ]---

Fix this by calling remove_extent_mapping(), at btrfs_remove_block_group(),
only at the very end, after removing the block group item key from the
extent tree (and removing the free space tree entry if we are using the
free space tree feature).

Fixes: 0421682 ("Btrfs: fix race between fs trimming and block group remove/allocation")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various fixes for mlxsw.

Patch #1 fixes an hash polarization problem when a nexthop device is a
LAG device. This is caused by the fact that the same seed is used for
the LAG and ECMP hash functions.

Patch #2 fixes an issue in which the driver fails to refresh a nexthop
neighbour after it becomes dead. This prevents the nexthop from ever
being written to the adjacency table and used to forward traffic. Patch

Patch #4 fixes a wrong extraction of TOS value in flower offload code.
Patch #5 is a test case.

Patch #6 works around a buffer issue in Spectrum-2 by reducing the
default sizes of the shared buffer pools.

Patch #7 prevents prio-tagged packets from entering the switch when PVID
is removed from the bridge port.

Please consider patches #2, #4 and #6 for 5.1.y
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Jul 13, 2019
There was the below bug report from Wu Fangsuo.

On the CMA allocation path, isolate_migratepages_range() could isolate
unevictable LRU pages and reclaim_clean_page_from_list() can try to
reclaim them if they are clean file-backed pages.

  page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24
  flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked)
  raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053
  raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80
  page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page))
  page->mem_cgroup:ffffffc09bf3ee80
  ------------[ cut here ]------------
  kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S              4.14.81 #3
  Hardware name: ASR AQUILAC EVB (DT)
  task: ffffffc00a54cd00 task.stack: ffffffc009b00000
  PC is at shrink_page_list+0x1998/0x3240
  LR is at shrink_page_list+0x1998/0x3240
  pc : [<ffffff90083a2158>] lr : [<ffffff90083a2158>] pstate: 60400045
  sp : ffffffc009b05940
  ..
     shrink_page_list+0x1998/0x3240
     reclaim_clean_pages_from_list+0x3c0/0x4f0
     alloc_contig_range+0x3bc/0x650
     cma_alloc+0x214/0x668
     ion_cma_allocate+0x98/0x1d8
     ion_alloc+0x200/0x7e0
     ion_ioctl+0x18c/0x378
     do_vfs_ioctl+0x17c/0x1780
     SyS_ioctl+0xac/0xc0

Wu found it's due to commit ad6b670 ("mm: remove SWAP_MLOCK in
ttu").  Before that, unevictable pages go to cull_mlocked so that we
can't reach the VM_BUG_ON_PAGE line.

To fix the issue, this patch filters out unevictable LRU pages from the
reclaim_clean_pages_from_list in CMA.

Link: http://lkml.kernel.org/r/20190524071114.74202-1-minchan@kernel.org
Fixes: ad6b670 ("mm: remove SWAP_MLOCK in ttu")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Debugged-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Tested-by: Wu Fangsuo <fangsuowu@asrmicro.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Pankaj Suryawanshi <pankaj.suryawanshi@einfochips.com>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Just like the case of commit 8b05a3a ("tracing/kprobes: Fix NULL
pointer dereference in trace_kprobe_create()"), writing an incorrectly
formatted string to uprobe_events can trigger NULL pointer dereference.

Reporeducer:

  # echo r > /sys/kernel/debug/tracing/uprobe_events

dmesg:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ torvalds#15
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  RIP: 0010:strchr+0x0/0x30
  Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c
  RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293

  RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625
  RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000
  RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
  R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000
  FS:  00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0
  Call Trace:
   trace_uprobe_create+0xe6/0xb10
   ? __kmalloc_track_caller+0xe6/0x1c0
   ? __kmalloc+0xf0/0x1d0
   ? trace_uprobe_create+0xb10/0xb10
   create_or_delete_trace_uprobe+0x35/0x90
   ? trace_uprobe_create+0xb10/0xb10
   trace_run_command+0x9c/0xb0
   trace_parse_run_command+0xf9/0x1eb
   ? probes_open+0x80/0x80
   __vfs_write+0x43/0x90
   vfs_write+0x14a/0x2a0
   ksys_write+0xa2/0x170
   do_syscall_64+0x7f/0x200
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com

Cc: stable@vger.kernel.org
Fixes: 0597c49 ("tracing/uprobes: Use dyn_event framework for uprobe events")
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
It's possible for livepatch and ftrace to be toggling a module's text
permissions at the same time, resulting in the following panic:

  BUG: unable to handle page fault for address: ffffffffc005b1d9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 3ea0c067 P4D 3ea0c067 PUD 3ea0e067 PMD 3cc13067 PTE 3b8a1061
  Oops: 0003 [#1] PREEMPT SMP PTI
  CPU: 1 PID: 453 Comm: insmod Tainted: G           O  K   5.2.0-rc1-a188339ca5 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
  RIP: 0010:apply_relocate_add+0xbe/0x14c
  Code: fa 0b 74 21 48 83 fa 18 74 38 48 83 fa 0a 75 40 eb 08 48 83 38 00 74 33 eb 53 83 38 00 75 4e 89 08 89 c8 eb 0a 83 38 00 75 43 <89> 08 48 63 c1 48 39 c8 74 2e eb 48 83 38 00 75 32 48 29 c1 89 08
  RSP: 0018:ffffb223c00dbb10 EFLAGS: 00010246
  RAX: ffffffffc005b1d9 RBX: 0000000000000000 RCX: ffffffff8b200060
  RDX: 000000000000000b RSI: 0000004b0000000b RDI: ffff96bdfcd33000
  RBP: ffffb223c00dbb38 R08: ffffffffc005d040 R09: ffffffffc005c1f0
  R10: ffff96bdfcd33c40 R11: ffff96bdfcd33b80 R12: 0000000000000018
  R13: ffffffffc005c1f0 R14: ffffffffc005e708 R15: ffffffff8b2fbc74
  FS:  00007f5f447beba8(0000) GS:ffff96bdff900000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffffffc005b1d9 CR3: 000000003cedc002 CR4: 0000000000360ea0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   klp_init_object_loaded+0x10f/0x219
   ? preempt_latency_start+0x21/0x57
   klp_enable_patch+0x662/0x809
   ? virt_to_head_page+0x3a/0x3c
   ? kfree+0x8c/0x126
   patch_init+0x2ed/0x1000 [livepatch_test02]
   ? 0xffffffffc0060000
   do_one_initcall+0x9f/0x1c5
   ? kmem_cache_alloc_trace+0xc4/0xd4
   ? do_init_module+0x27/0x210
   do_init_module+0x5f/0x210
   load_module+0x1c41/0x2290
   ? fsnotify_path+0x3b/0x42
   ? strstarts+0x2b/0x2b
   ? kernel_read+0x58/0x65
   __do_sys_finit_module+0x9f/0xc3
   ? __do_sys_finit_module+0x9f/0xc3
   __x64_sys_finit_module+0x1a/0x1c
   do_syscall_64+0x52/0x61
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The above panic occurs when loading two modules at the same time with
ftrace enabled, where at least one of the modules is a livepatch module:

CPU0					CPU1
klp_enable_patch()
  klp_init_object_loaded()
    module_disable_ro()
    					ftrace_module_enable()
					  ftrace_arch_code_modify_post_process()
				    	    set_all_modules_text_ro()
      klp_write_object_relocations()
        apply_relocate_add()
	  *patches read-only code* - BOOM

A similar race exists when toggling ftrace while loading a livepatch
module.

Fix it by ensuring that the livepatch and ftrace code patching
operations -- and their respective permissions changes -- are protected
by the text_mutex.

Link: http://lkml.kernel.org/r/ab43d56ab909469ac5d2520c5d944ad6d4abd476.1560474114.git.jpoimboe@redhat.com

Reported-by: Johannes Erdfelt <johannes@erdfelt.com>
Fixes: 444d13f ("modules: add ro_after_init support")
Acked-by: Jessica Yu <jeyu@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
The mapper may be NULL when called from register_ftrace_function_probe()
with probe->data == NULL.

This issue can be reproduced as follow (it may be covered by compiler
optimization sometime):

/ # cat /sys/kernel/debug/tracing/set_ftrace_filter
#### all functions enabled ####
/ # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter
[  206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  206.952402] Mem abort info:
[  206.952819]   ESR = 0x96000006
[  206.955326]   Exception class = DABT (current EL), IL = 32 bits
[  206.955844]   SET = 0, FnV = 0
[  206.956272]   EA = 0, S1PTW = 0
[  206.956652] Data abort info:
[  206.957320]   ISV = 0, ISS = 0x00000006
[  206.959271]   CM = 0, WnR = 0
[  206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000
[  206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000
[  206.964953] Internal error: Oops: 96000006 [#1] SMP
[  206.971122] Dumping ftrace buffer:
[  206.973677]    (ftrace buffer empty)
[  206.975258] Modules linked in:
[  206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____))
[  206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ torvalds#17
[  206.978955] Hardware name: linux,dummy-virt (DT)
[  206.979883] pstate: 60000005 (nZCv daif -PAN -UAO)
[  206.980499] pc : free_ftrace_func_mapper+0x2c/0x118
[  206.980874] lr : ftrace_count_free+0x68/0x80
[  206.982539] sp : ffff0000182f3ab0
[  206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700
[  206.983632] x27: ffff000013054b40 x26: 0000000000000001
[  206.984000] x25: ffff00001385f000 x24: 0000000000000000
[  206.984394] x23: ffff000013453000 x22: ffff000013054000
[  206.984775] x21: 0000000000000000 x20: ffff00001385fe28
[  206.986575] x19: ffff000013872c30 x18: 0000000000000000
[  206.987111] x17: 0000000000000000 x16: 0000000000000000
[  206.987491] x15: ffffffffffffffb0 x14: 0000000000000000
[  206.987850] x13: 000000000017430e x12: 0000000000000580
[  206.988251] x11: 0000000000000000 x10: cccccccccccccccc
[  206.988740] x9 : 0000000000000000 x8 : ffff000013917550
[  206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000
[  206.991008] x5 : ffff0000103da588 x4 : 0000000000000001
[  206.991395] x3 : 0000000000000001 x2 : ffff000013872a28
[  206.991771] x1 : 0000000000000000 x0 : 0000000000000000
[  206.992557] Call trace:
[  206.993101]  free_ftrace_func_mapper+0x2c/0x118
[  206.994827]  ftrace_count_free+0x68/0x80
[  206.995238]  release_probe+0xfc/0x1d0
[  206.995555]  register_ftrace_function_probe+0x4a8/0x868
[  206.995923]  ftrace_trace_probe_callback.isra.4+0xb8/0x180
[  206.996330]  ftrace_dump_callback+0x50/0x70
[  206.996663]  ftrace_regex_write.isra.29+0x290/0x3a8
[  206.997157]  ftrace_filter_write+0x44/0x60
[  206.998971]  __vfs_write+0x64/0xf0
[  206.999285]  vfs_write+0x14c/0x2f0
[  206.999591]  ksys_write+0xbc/0x1b0
[  206.999888]  __arm64_sys_write+0x3c/0x58
[  207.000246]  el0_svc_common.constprop.0+0x408/0x5f0
[  207.000607]  el0_svc_handler+0x144/0x1c8
[  207.000916]  el0_svc+0x8/0xc
[  207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303)
[  207.008388] ---[ end trace 7b6d11b5f542bdf1 ]---
[  207.010126] Kernel panic - not syncing: Fatal exception
[  207.011322] SMP: stopping secondary CPUs
[  207.013956] Dumping ftrace buffer:
[  207.014595]    (ftrace buffer empty)
[  207.015632] Kernel Offset: disabled
[  207.017187] CPU features: 0x002,20006008
[  207.017985] Memory Limit: none
[  207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]---

Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Reinhard Speyerer says:

====================
qmi_wwan: fix QMAP handling

This series addresses the following issues observed when using the
QMAP support of the qmi_wwan driver:

1. The QMAP code in the qmi_wwan driver is based on the CodeAurora
   GobiNet driver ([1], [2]) which does not process QMAP padding
   in the RX path correctly. This causes qmimux_rx_fixup() to pass
   incorrect data to the IP stack when padding is used.

2. qmimux devices currently lack proper network device usage statistics.

3. RCU stalls on device disconnect with QMAP activated like this

   # echo Y > /sys/class/net/wwan0/qmi/raw_ip
   # echo 1 > /sys/class/net/wwan0/qmi/add_mux
   # echo 2 > /sys/class/net/wwan0/qmi/add_mux
   # echo 3 > /sys/class/net/wwan0/qmi/add_mux

   have been observed in certain setups:

   [ 2273.676593] option1 ttyUSB16: GSM modem (1-port) converter now disconnected from ttyUSB16
   [ 2273.676617] option 6-1.2:1.0: device disconnected
   [ 2273.676774] WARNING: CPU: 1 PID: 141 at kernel/rcu/tree_plugin.h:342 rcu_note_context_switch+0x2a/0x3d0
   [ 2273.676776] Modules linked in: option qmi_wwan cdc_mbim cdc_ncm qcserial cdc_wdm usb_wwan sierra sierra_net usbnet mii edd coretemp iptable_mangle ip6_tables iptable_filter ip_tables cdc_acm dm_mod dax iTCO_wdt evdev iTCO_vendor_support sg ftdi_sio usbserial e1000e ptp pps_core i2c_i801 ehci_pci button lpc_ich i2c_core mfd_core uhci_hcd ehci_hcd rtc_cmos usbcore usb_common sd_mod fan ata_piix thermal
   [ 2273.676817] CPU: 1 PID: 141 Comm: kworker/1:1 Not tainted 4.19.38-rsp-1 #1
   [ 2273.676819] Hardware name: Not Applicable   Not Applicable  /CX-GS/GM45-GL40             , BIOS V1.11      03/23/2011
   [ 2273.676828] Workqueue: usb_hub_wq hub_event [usbcore]
   [ 2273.676832] EIP: rcu_note_context_switch+0x2a/0x3d0
   [ 2273.676834] Code: 55 89 e5 57 56 89 c6 53 83 ec 14 89 45 f0 e8 5d ff ff ff 89 f0 64 8b 3d 24 a6 86 c0 84 c0 8b 87 04 02 00 00 75 7a 85 c0 7e 7a <0f> 0b 80 bf 08 02 00 00 00 0f 84 87 00 00 00 e8 b2 e2 ff ff bb dc
   [ 2273.676836] EAX: 00000001 EBX: f614bc00 ECX: 00000001 EDX: c0715b81
   [ 2273.676838] ESI: 00000000 EDI: f18beb40 EBP: f1a3dc20 ESP: f1a3dc00
   [ 2273.676840] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010002
   [ 2273.676842] CR0: 80050033 CR2: b7e97230 CR3: 2f9c4000 CR4: 000406b0
   [ 2273.676843] Call Trace:
   [ 2273.676847]  ? preempt_count_add+0xa5/0xc0
   [ 2273.676852]  __schedule+0x4e/0x4f0
   [ 2273.676855]  ? __queue_work+0xf1/0x2a0
   [ 2273.676858]  ? _raw_spin_lock_irqsave+0x14/0x40
   [ 2273.676860]  ? preempt_count_add+0x52/0xc0
   [ 2273.676862]  schedule+0x33/0x80
   [ 2273.676865]  _synchronize_rcu_expedited+0x24e/0x280
   [ 2273.676867]  ? rcu_accelerate_cbs_unlocked+0x70/0x70
   [ 2273.676871]  ? wait_woken+0x70/0x70
   [ 2273.676873]  ? rcu_accelerate_cbs_unlocked+0x70/0x70
   [ 2273.676875]  ? _synchronize_rcu_expedited+0x280/0x280
   [ 2273.676877]  synchronize_rcu_expedited+0x22/0x30
   [ 2273.676881]  synchronize_net+0x25/0x30
   [ 2273.676885]  dev_deactivate_many+0x133/0x230
   [ 2273.676887]  ? preempt_count_add+0xa5/0xc0
   [ 2273.676890]  __dev_close_many+0x4d/0xc0
   [ 2273.676892]  ? skb_dequeue+0x40/0x50
   [ 2273.676895]  dev_close_many+0x5d/0xd0
   [ 2273.676898]  rollback_registered_many+0xbf/0x4c0
   [ 2273.676901]  ? raw_notifier_call_chain+0x1a/0x20
   [ 2273.676904]  ? call_netdevice_notifiers_info+0x23/0x60
   [ 2273.676906]  ? netdev_master_upper_dev_get+0xe/0x70
   [ 2273.676908]  rollback_registered+0x1f/0x30
   [ 2273.676911]  unregister_netdevice_queue+0x47/0xb0
   [ 2273.676915]  qmimux_unregister_device+0x1f/0x30 [qmi_wwan]
   [ 2273.676917]  qmi_wwan_disconnect+0x5d/0x90 [qmi_wwan]
   ...
   [ 2273.677001] ---[ end trace 0fcc5f88496b485a ]---
   [ 2294.679136] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
   [ 2294.679140] rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P141
   [ 2294.679144] rcu: 	(detected by 0, t=21002 jiffies, g=265857, q=8446)
   [ 2294.679148] kworker/1:1     D    0   141      2 0x80000000

In addition the permitted QMAP mux_id value range is extended for
compatibility with ip(8) and the rmnet driver.

Reinhard

[1]: https://portland.source.codeaurora.org/patches/quic/gobi
[2]: https://portland.source.codeaurora.org/quic/qsdk/oss/lklm/gobinet/
====================

Tested-by: Daniele Palmas <dnlplm@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Commit c1fe190 ("powerpc: Add force enable of DAWR on P9 option")
screwed up some assembler and corrupted a pointer in r3. This resulted
in crashes like the below:

  BUG: Kernel NULL pointer dereference at 0x000013bf
  Faulting instruction address: 0xc00000000010b044
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  CPU: 8 PID: 1771 Comm: qemu-system-ppc Kdump: loaded Not tainted 5.2.0-rc4+ #3
  NIP:  c00000000010b044 LR: c0080000089dacf4 CTR: c00000000010aff4
  REGS: c00000179b397710 TRAP: 0300   Not tainted  (5.2.0-rc4+)
  MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 42244842  XER: 00000000
  CFAR: c00000000010aff8 DAR: 00000000000013bf DSISR: 42000000 IRQMASK: 0
  GPR00: c0080000089dd6bc c00000179b3979a0 c008000008a04300 ffffffffffffffff
  GPR04: 0000000000000000 0000000000000003 000000002444b05d c0000017f11c45d0
  ...
  NIP kvmppc_h_set_dabr+0x50/0x68
  LR  kvmppc_pseries_do_hcall+0xa3c/0xeb0 [kvm_hv]
  Call Trace:
    0xc0000017f11c0000 (unreliable)
    kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv]
    kvmppc_vcpu_run+0x34/0x48 [kvm]
    kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
    kvm_vcpu_ioctl+0x460/0x850 [kvm]
    do_vfs_ioctl+0xe4/0xb40
    ksys_ioctl+0xc4/0x110
    sys_ioctl+0x28/0x80
    system_call+0x5c/0x70
  Instruction dump:
  4082fff4 4c00012c 38600000 4e800020 e96280c0 896b0000 2c2b0000 3860ffff
  4d820020 50852e74 508516f6 78840724 <f88313c0> f8a313c8 7c942ba6 7cbc2ba6

Fix the bug by only changing r3 when we are returning immediately.

Fixes: c1fe190 ("powerpc: Add force enable of DAWR on P9 option")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reported-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
heikomat pushed a commit that referenced this issue Jul 13, 2019
The kernel panic was observed during iSCSI discovery via offload with below
call trace,

[ 2115.646901] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 2115.646909] IP: [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.646927] PGD 0
[ 2115.646932] Oops: 0000 [#1] SMP
[ 2115.647107] CPU: 24 PID: 264 Comm: kworker/24:1 Kdump: loaded Tainted: G
               OE  ------------   3.10.0-957.el7.x86_64 #1
[ 2115.647133] Workqueue: slowpath-13:00. qed_slowpath_task [qed]
[ 2115.647135] task: ffff8d66af80b0c0 ti: ffff8d66afb80000 task.ti: ffff8d66afb80000
[ 2115.647136] RIP: 0010:[<ffffffffacf7f0cc>]  [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.647141] RSP: 0018:ffff8d66afb83c68  EFLAGS: 00010206
[ 2115.647143] RAX: 0000000000000001 RBX: 0000000000000007 RCX: 000000000000000a
[ 2115.647144] RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8d632b3ba040
[ 2115.647145] RBP: ffff8d66afb83c68 R08: 0000000000000000 R09: 000000000000ffff
[ 2115.647147] R10: 0000000000000007 R11: 0000000000000800 R12: ffff8d66a30007a0
[ 2115.647148] R13: ffff8d66747a3c10 R14: ffff8d632b3ba000 R15: ffff8d66747a32f8
[ 2115.647149] FS:  0000000000000000(0000) GS:ffff8d66aff00000(0000) knlGS:0000000000000000
[ 2115.647151] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2115.647152] CR2: 0000000000000000 CR3: 0000000509610000 CR4: 00000000007607e0
[ 2115.647153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2115.647154] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2115.647155] PKRU: 00000000
[ 2115.647157] Call Trace:
[ 2115.647165]  [<ffffffffc0634cc5>] qedi_get_protocol_tlv_data+0x2c5/0x510 [qedi]
[ 2115.647184]  [<ffffffffc05968f5>] ? qed_mfw_process_tlv_req+0x245/0xbe0 [qed]
[ 2115.647195]  [<ffffffffc05496cb>] qed_mfw_fill_tlv_data+0x4b/0xb0 [qed]
[ 2115.647206]  [<ffffffffc0596911>] qed_mfw_process_tlv_req+0x261/0xbe0 [qed]
[ 2115.647215]  [<ffffffffacce0e8e>] ? dequeue_task_fair+0x41e/0x660
[ 2115.647221]  [<ffffffffacc2a59e>] ? __switch_to+0xce/0x580
[ 2115.647230]  [<ffffffffc0546013>] qed_slowpath_task+0xa3/0x160 [qed]
[ 2115.647278] RIP  [<ffffffffacf7f0cc>] strncmp+0xc/0x60

Fix kernel panic by validating the session targetname before providing TLV
data and confirming the presence of boot targets.

Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
After commit d4fc506 ("mm: switch s_mem and slab_cache in struct page")
page->mapping will be re-used by slab allocations and page->mapping->host
will be used in balance_dirty_pages_ratelimited() as an inode member but
it's not an inode in fact and leads an oops.

[  159.906493] Unable to handle kernel paging request at virtual address ffff200012d90be8
[  159.908029] Mem abort info:
[  159.908552]   ESR = 0x96000007
[  159.909138]   Exception class = DABT (current EL), IL = 32 bits
[  159.910155]   SET = 0, FnV = 0
[  159.910690]   EA = 0, S1PTW = 0
[  159.911241] Data abort info:
[  159.911846]   ISV = 0, ISS = 0x00000007
[  159.912567]   CM = 0, WnR = 0
[  159.913105] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000042acd000
[  159.914269] [ffff200012d90be8] pgd=000000043ffff003, pud=000000043fffe003, pmd=000000043fffa003, pte=0000000000000000
[  159.916280] Internal error: Oops: 96000007 [#1] SMP
[  159.917195] Dumping ftrace buffer:
[  159.917845]    (ftrace buffer empty)
[  159.918521] Modules linked in: uio_dev(OE)
[  159.919276] CPU: 1 PID: 295 Comm: uio_test Tainted: G           OE     5.2.0-rc4+ torvalds#46
[  159.920859] Hardware name: linux,dummy-virt (DT)
[  159.921815] pstate: 60000005 (nZCv daif -PAN -UAO)
[  159.922809] pc : balance_dirty_pages_ratelimited+0x68/0xc38
[  159.923965] lr : fault_dirty_shared_page.isra.8+0xe4/0x100
[  159.925134] sp : ffff800368a77ae0
[  159.925824] x29: ffff800368a77ae0 x28: 1ffff0006d14ce1a
[  159.926906] x27: ffff800368a670d0 x26: ffff800368a67120
[  159.927985] x25: 1ffff0006d10f5fe x24: ffff200012d90be8
[  159.929089] x23: ffff200013732000 x22: ffff80036ec03200
[  159.930172] x21: ffff200012d90bc0 x20: 1fffe400025b217d
[  159.931253] x19: ffff80036ec03200 x18: 0000000000000000
[  159.932348] x17: 0000000000000000 x16: 0ffffe0000010208
[  159.933439] x15: 0000000000000000 x14: 0000000000000000
[  159.934518] x13: 0000000000000000 x12: 0000000000000000
[  159.935596] x11: 1fffefc001b452c0 x10: ffff0fc001b452c0
[  159.936697] x9 : dfff200000000000 x8 : dfff200000000001
[  159.937781] x7 : ffff7e000da29607 x6 : ffff0fc001b452c1
[  159.938859] x5 : ffff0fc001b452c1 x4 : ffff0fc001b452c1
[  159.939944] x3 : ffff200010523ad4 x2 : 1fffe400026e659b
[  159.941065] x1 : dfff200000000000 x0 : ffff200013732cd8
[  159.942205] Call trace:
[  159.942732]  balance_dirty_pages_ratelimited+0x68/0xc38
[  159.943797]  fault_dirty_shared_page.isra.8+0xe4/0x100
[  159.944867]  do_fault+0x608/0x1250
[  159.945571]  __handle_mm_fault+0x93c/0xfb8
[  159.946412]  handle_mm_fault+0x1c0/0x360
[  159.947224]  do_page_fault+0x358/0x8d0
[  159.947993]  do_translation_fault+0xf8/0x124
[  159.948884]  do_mem_abort+0x70/0x190
[  159.949624]  el0_da+0x24/0x28

According another commit 5e901d0 ("scsi: qedi: Fix bad pte call trace
when iscsiuio is stopped."), using kmalloc also cause other problem.

But the documentation about UIO_MEM_LOGICAL allows using kmalloc(), remove
and don't allow using kmalloc() in documentation.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Stephen reports:

I hit the following General Protection Fault when testing io_uring via
the io_uring engine in fio. This was on a VM running 5.2-rc5 and the
latest version of fio. The issue occurs for both null_blk and fake NVMe
drives. I have not tested bare metal or real NVMe SSDs. The fio script
used is given below.

[io_uring]
time_based=1
runtime=60
filename=/dev/nvme2n1 (note /dev/nullb0 also fails)
ioengine=io_uring
bs=4k
rw=readwrite
direct=1
fixedbufs=1
sqthread_poll=1
sqthread_poll_cpu=0

general protection fault: 0000 [#1] SMP PTI
CPU: 0 PID: 872 Comm: io_uring-sq Not tainted 5.2.0-rc5-cpacket-io-uring #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
RIP: 0010:fput_many+0x7/0x90
Code: 01 48 85 ff 74 17 55 48 89 e5 53 48 8b 1f e8 a0 f9 ff ff 48 85 db 48 89 df 75 f0 5b 5d f3 c3 0f 1f 40 00 0f 1f 44 00 00 89 f6 <f0> 48 29 77 38 74 01 c3 55 48 89 e5 53 48 89 fb 65 48 \

RSP: 0018:ffffadeb817ebc50 EFLAGS: 00010246
RAX: 0000000000000004 RBX: ffff8f46ad477480 RCX: 0000000000001805
RDX: 0000000000000000 RSI: 0000000000000001 RDI: f18b51b9a39552b5
RBP: ffffadeb817ebc58 R08: ffff8f46b7a318c0 R09: 000000000000015d
R10: ffffadeb817ebce8 R11: 0000000000000020 R12: ffff8f46ad4cd000
R13: 00000000fffffff7 R14: ffffadeb817ebe30 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff8f46b7a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055828f0bbbf0 CR3: 0000000232176004 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? fput+0x13/0x20
 io_free_req+0x20/0x40
 io_put_req+0x1b/0x20
 io_submit_sqe+0x40a/0x680
 ? __switch_to_asm+0x34/0x70
 ? __switch_to_asm+0x40/0x70
 io_submit_sqes+0xb9/0x160
 ? io_submit_sqes+0xb9/0x160
 ? __switch_to_asm+0x40/0x70
 ? __switch_to_asm+0x34/0x70
 ? __schedule+0x3f2/0x6a0
 ? __switch_to_asm+0x34/0x70
 io_sq_thread+0x1af/0x470
 ? __switch_to_asm+0x34/0x70
 ? wait_woken+0x80/0x80
 ? __switch_to+0x85/0x410
 ? __switch_to_asm+0x40/0x70
 ? __switch_to_asm+0x34/0x70
 ? __schedule+0x3f2/0x6a0
 kthread+0x105/0x140
 ? io_submit_sqes+0x160/0x160
 ? kthread+0x105/0x140
 ? io_submit_sqes+0x160/0x160
 ? kthread_destroy_worker+0x50/0x50
 ret_from_fork+0x35/0x40

which occurs because using a kernel side submission thread isn't valid
without using fixed files (registered through io_uring_register()). This
causes io_uring to put the request after logging an error, but before
the file field is set in the request. If it happens to be non-zero, we
attempt to fput() garbage.

Fix this by ensuring that req->file is initialized when the request is
allocated.

Cc: stable@vger.kernel.org # 5.1+
Reported-by: Stephen Bates <sbates@raithlin.com>
Tested-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
heikomat pushed a commit that referenced this issue Jul 13, 2019
…_domain_lock"

This reverts commit 7560cc3.

With 5.2.0-rc5 I can easily trigger this with lockdep and iommu=pt:

    ======================================================
    WARNING: possible circular locking dependency detected
    5.2.0-rc5 torvalds#78 Not tainted
    ------------------------------------------------------
    swapper/0/1 is trying to acquire lock:
    00000000ea2b3beb (&(&iommu->lock)->rlock){+.+.}, at: domain_context_mapping_one+0xa5/0x4e0
    but task is already holding lock:
    00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0
    which lock already depends on the new lock.
    the existing dependency chain (in reverse order) is:
    -> #1 (device_domain_lock){....}:
           _raw_spin_lock_irqsave+0x3c/0x50
           dmar_insert_one_dev_info+0xbb/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50
    -> #0 (&(&iommu->lock)->rlock){+.+.}:
           lock_acquire+0x9e/0x170
           _raw_spin_lock+0x25/0x30
           domain_context_mapping_one+0xa5/0x4e0
           pci_for_each_dma_alias+0x30/0x140
           dmar_insert_one_dev_info+0x3b2/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50

    other info that might help us debug this:
     Possible unsafe locking scenario:
           CPU0                    CPU1
           ----                    ----
      lock(device_domain_lock);
                                   lock(&(&iommu->lock)->rlock);
                                   lock(device_domain_lock);
      lock(&(&iommu->lock)->rlock);

     *** DEADLOCK ***
    2 locks held by swapper/0/1:
     #0: 00000000033eb13d (dmar_global_lock){++++}, at: intel_iommu_init+0x1e0/0x1422
     #1: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0

    stack backtrace:
    CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5 torvalds#78
    Hardware name: LENOVO 20KGS35G01/20KGS35G01, BIOS N23ET50W (1.25 ) 06/25/2018
    Call Trace:
     dump_stack+0x85/0xc0
     print_circular_bug.cold.57+0x15c/0x195
     __lock_acquire+0x152a/0x1710
     lock_acquire+0x9e/0x170
     ? domain_context_mapping_one+0xa5/0x4e0
     _raw_spin_lock+0x25/0x30
     ? domain_context_mapping_one+0xa5/0x4e0
     domain_context_mapping_one+0xa5/0x4e0
     ? domain_context_mapping_one+0x4e0/0x4e0
     pci_for_each_dma_alias+0x30/0x140
     dmar_insert_one_dev_info+0x3b2/0x510
     domain_add_dev_info+0x50/0x90
     dev_prepare_static_identity_mapping+0x30/0x68
     intel_iommu_init+0xddd/0x1422
     ? printk+0x58/0x6f
     ? lockdep_hardirqs_on+0xf0/0x180
     ? do_early_param+0x8e/0x8e
     ? e820__memblock_setup+0x63/0x63
     pci_iommu_init+0x16/0x3f
     do_one_initcall+0x5d/0x2b4
     ? do_early_param+0x8e/0x8e
     ? rcu_read_lock_sched_held+0x55/0x60
     ? do_early_param+0x8e/0x8e
     kernel_init_freeable+0x218/0x2c1
     ? rest_init+0x230/0x230
     kernel_init+0xa/0x100
     ret_from_fork+0x3a/0x50

domain_context_mapping_one() is taking device_domain_lock first then
iommu lock, while dmar_insert_one_dev_info() is doing the reverse.

That should be introduced by commit:

7560cc3 ("iommu/vt-d: Fix lock inversion between iommu->lock and
              device_domain_lock", 2019-05-27)

So far I still cannot figure out how the previous deadlock was
triggered (I cannot find iommu lock taken before calling of
iommu_flush_dev_iotlb()), however I'm pretty sure that that change
should be incomplete at least because it does not fix all the places
so we're still taking the locks in different orders, while reverting
that commit is very clean to me so far that we should always take
device_domain_lock first then the iommu lock.

We can continue to try to find the real culprit mentioned in
7560cc3, but for now I think we should revert it to fix current
breakage.

CC: Joerg Roedel <joro@8bytes.org>
CC: Lu Baolu <baolu.lu@linux.intel.com>
CC: dave.jiang@intel.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Kyle has reported occasional crashes when booting a kernel in 5-level
paging mode with KASLR enabled:

  WARNING: CPU: 0 PID: 0 at arch/x86/mm/init_64.c:87 phys_p4d_init+0x1d4/0x1ea
  RIP: 0010:phys_p4d_init+0x1d4/0x1ea
  Call Trace:
   __kernel_physical_mapping_init+0x10a/0x35c
   kernel_physical_mapping_init+0xe/0x10
   init_memory_mapping+0x1aa/0x3b0
   init_range_memory_mapping+0xc8/0x116
   init_mem_mapping+0x225/0x2eb
   setup_arch+0x6ff/0xcf5
   start_kernel+0x64/0x53b
   ? copy_bootdata+0x1f/0xce
   x86_64_start_reservations+0x24/0x26
   x86_64_start_kernel+0x8a/0x8d
   secondary_startup_64+0xb6/0xc0

which causes later:

  BUG: unable to handle page fault for address: ff484d019580eff8
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  BAD
  Oops: 0000 [#1] SMP NOPTI
  RIP: 0010:fill_pud+0x13/0x130
  Call Trace:
   set_pte_vaddr_p4d+0x2e/0x50
   set_pte_vaddr+0x6f/0xb0
   __native_set_fixmap+0x28/0x40
   native_set_fixmap+0x39/0x70
   register_lapic_address+0x49/0xb6
   early_acpi_boot_init+0xa5/0xde
   setup_arch+0x944/0xcf5
   start_kernel+0x64/0x53b

Kyle bisected the issue to commit b569c18 ("x86/mm/KASLR: Reduce
randomization granularity for 5-level paging to 1GB")

Before this commit PAGE_OFFSET was always aligned to P4D_SIZE when booting
5-level paging mode. But now only PUD_SIZE alignment is guaranteed.

In the case I was able to reproduce the following vaddr/paddr values were
observed in phys_p4d_init():

Iteration     vaddr			paddr
   1 	      0xff4228027fe00000 	0x033fe00000
   2	      0xff42287f40000000	0x8000000000

'vaddr' in both cases belongs to the same p4d entry.

But due to the original assumption that PAGE_OFFSET is aligned to P4D_SIZE
this overlap cannot be handled correctly. The code assumes strictly aligned
entries and unconditionally increments the index into the P4D table, which
creates false duplicate entries. Once the index reaches the end, the last
entry in the page table is missing.

Aside of that the 'paddr >= paddr_end' condition can evaluate wrong which
causes an P4D entry to be cleared incorrectly.

Change the loop in phys_p4d_init() to walk purely based on virtual
addresses like __kernel_physical_mapping_init() does. This makes it work
correctly with unaligned virtual addresses.

Fixes: b569c18 ("x86/mm/KASLR: Reduce randomization granularity for 5-level paging to 1GB")
Reported-by: Kyle Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kyle Pelton <kyle.d.pelton@intel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190624123150.920-1-kirill.shutemov@linux.intel.com
heikomat pushed a commit that referenced this issue Jul 13, 2019
…race_run_update_code()

The commit 9f255b6 ("module: Fix livepatch/ftrace module text
permissions race") causes a possible deadlock between register_kprobe()
and ftrace_run_update_code() when ftrace is using stop_machine().

The existing dependency chain (in reverse order) is:

-> #1 (text_mutex){+.+.}:
       validate_chain.isra.21+0xb32/0xd70
       __lock_acquire+0x4b8/0x928
       lock_acquire+0x102/0x230
       __mutex_lock+0x88/0x908
       mutex_lock_nested+0x32/0x40
       register_kprobe+0x254/0x658
       init_kprobes+0x11a/0x168
       do_one_initcall+0x70/0x318
       kernel_init_freeable+0x456/0x508
       kernel_init+0x22/0x150
       ret_from_fork+0x30/0x34
       kernel_thread_starter+0x0/0xc

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       check_prev_add+0x90c/0xde0
       validate_chain.isra.21+0xb32/0xd70
       __lock_acquire+0x4b8/0x928
       lock_acquire+0x102/0x230
       cpus_read_lock+0x62/0xd0
       stop_machine+0x2e/0x60
       arch_ftrace_update_code+0x2e/0x40
       ftrace_run_update_code+0x40/0xa0
       ftrace_startup+0xb2/0x168
       register_ftrace_function+0x64/0x88
       klp_patch_object+0x1a2/0x290
       klp_enable_patch+0x554/0x980
       do_one_initcall+0x70/0x318
       do_init_module+0x6e/0x250
       load_module+0x1782/0x1990
       __s390x_sys_finit_module+0xaa/0xf0
       system_call+0xd8/0x2d0

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(text_mutex);
                               lock(cpu_hotplug_lock.rw_sem);
                               lock(text_mutex);
  lock(cpu_hotplug_lock.rw_sem);

It is similar problem that has been solved by the commit 2d1e38f
("kprobes: Cure hotplug lock ordering issues"). Many locks are involved.
To be on the safe side, text_mutex must become a low level lock taken
after cpu_hotplug_lock.rw_sem.

This can't be achieved easily with the current ftrace design.
For example, arm calls set_all_modules_text_rw() already in
ftrace_arch_code_modify_prepare(), see arch/arm/kernel/ftrace.c.
This functions is called:

  + outside stop_machine() from ftrace_run_update_code()
  + without stop_machine() from ftrace_module_enable()

Fortunately, the problematic fix is needed only on x86_64. It is
the only architecture that calls set_all_modules_text_rw()
in ftrace path and supports livepatching at the same time.

Therefore it is enough to move text_mutex handling from the generic
kernel/trace/ftrace.c into arch/x86/kernel/ftrace.c:

   ftrace_arch_code_modify_prepare()
   ftrace_arch_code_modify_post_process()

This patch basically reverts the ftrace part of the problematic
commit 9f255b6 ("module: Fix livepatch/ftrace module
text permissions race"). And provides x86_64 specific-fix.

Some refactoring of the ftrace code will be needed when livepatching
is implemented for arm or nds32. These architectures call
set_all_modules_text_rw() and use stop_machine() at the same time.

Link: http://lkml.kernel.org/r/20190627081334.12793-1-pmladek@suse.com

Fixes: 9f255b6 ("module: Fix livepatch/ftrace module text permissions race")
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
[
  As reviewed by Miroslav Benes <mbenes@suse.cz>, removed return value of
  ftrace_run_update_code() as it is a void function.
]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Currently the calcuation of end_pfn can round up the pfn number to more
than the actual maximum number of pfns, causing an Oops.  Fix this by
ensuring end_pfn is never more than max_pfn.

This can be easily triggered when on systems where the end_pfn gets
rounded up to more than max_pfn using the idle-page stress-ng stress test:

sudo stress-ng --idle-page 0

  BUG: unable to handle kernel paging request at 00000000000020d8
  #PF error: [normal kernel read fault]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP PTI
  CPU: 1 PID: 11039 Comm: stress-ng-idle- Not tainted 5.0.0-5-generic #6-Ubuntu
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
  RIP: 0010:page_idle_get_page+0xc8/0x1a0
  Code: 0f b1 0a 75 7d 48 8b 03 48 89 c2 48 c1 e8 33 83 e0 07 48 c1 ea 36 48 8d 0c 40 4c 8d 24 88 49 c1 e4 07 4c 03 24 d5 00 89 c3 be <49> 8b 44 24 58 48 8d b8 80 a1 02 00 e8 07 d5 77 00 48 8b 53 08 48
  RSP: 0018:ffffafd7c672fde8 EFLAGS: 00010202
  RAX: 0000000000000005 RBX: ffffe36341fff700 RCX: 000000000000000f
  RDX: 0000000000000284 RSI: 0000000000000275 RDI: 0000000001fff700
  RBP: ffffafd7c672fe00 R08: ffffa0bc34056410 R09: 0000000000000276
  R10: ffffa0bc754e9b40 R11: ffffa0bc330f6400 R12: 0000000000002080
  R13: ffffe36341fff700 R14: 0000000000080000 R15: ffffa0bc330f6400
  FS: 00007f0ec1ea5740(0000) GS:ffffa0bc7db00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000020d8 CR3: 0000000077d68000 CR4: 00000000000006e0
  Call Trace:
    page_idle_bitmap_write+0x8c/0x140
    sysfs_kf_bin_write+0x5c/0x70
    kernfs_fop_write+0x12e/0x1b0
    __vfs_write+0x1b/0x40
    vfs_write+0xab/0x1b0
    ksys_write+0x55/0xc0
    __x64_sys_write+0x1a/0x20
    do_syscall_64+0x5a/0x110
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: http://lkml.kernel.org/r/20190618124352.28307-1-colin.king@canonical.com
Fixes: 33c3fc7 ("mm: introduce idle page tracking")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
heikomat pushed a commit that referenced this issue Jul 13, 2019
Make sure to return a proper negative error code from copy_process()
when anon_inode_getfile() fails with CLONE_PIDFD.
Otherwise _do_fork() will not detect an error and get_task_pid() will
operator on a nonsensical pointer:

R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007ffc15fbb0ff R14: 00007ff07e47e9c0 R15: 0000000000000000
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7990 Comm: syz-executor290 Not tainted 5.2.0-rc6+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline]
RIP: 0010:get_task_pid+0xe1/0x210 kernel/pid.c:372
Code: 89 ff e8 62 27 5f 00 49 8b 07 44 89 f1 4c 8d bc c8 90 01 00 00 eb 0c
e8 0d fe 25 00 49 81 c7 38 05 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74
08 4c 89 ff e8 31 27 5f 00 4d 8b 37 e8 f9 47 12 00
RSP: 0018:ffff88808a4a7d78 EFLAGS: 00010203
RAX: 00000000000000a7 RBX: dffffc0000000000 RCX: ffff888088180600
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88808a4a7d90 R08: ffffffff814fb3a8 R09: ffffed1015d66bf8
R10: ffffed1015d66bf8 R11: 1ffff11015d66bf7 R12: 0000000000041ffc
R13: 1ffff11011494fbc R14: 0000000000000000 R15: 000000000000053d
FS:  00007ff07e47e700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004b5100 CR3: 0000000094df2000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  _do_fork+0x1b9/0x5f0 kernel/fork.c:2360
  __do_sys_clone kernel/fork.c:2454 [inline]
  __se_sys_clone kernel/fork.c:2448 [inline]
  __x64_sys_clone+0xc1/0xd0 kernel/fork.c:2448
  do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: https://lore.kernel.org/lkml/000000000000e0dc0d058c9e7142@google.com
Reported-and-tested-by: syzbot+002e636502bc4b64eb5c@syzkaller.appspotmail.com
Fixes: 6fd2fe4 ("copy_process(): don't use ksys_close() on cleanups")
Cc: Jann Horn <jannh@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <christian@brauner.io>
heikomat pushed a commit that referenced this issue Jul 13, 2019
…pported

If the CHAP_A value is not supported, the chap_server_open() function
should free the auth_protocol pointer and set it to NULL, or we will leave
a dangling pointer around.

[   66.010905] Unsupported CHAP_A value
[   66.011660] Security negotiation failed.
[   66.012443] iSCSI Login negotiation failed.
[   68.413924] general protection fault: 0000 [#1] SMP PTI
[   68.414962] CPU: 0 PID: 1562 Comm: targetcli Kdump: loaded Not tainted 4.18.0-80.el8.x86_64 #1
[   68.416589] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[   68.417677] RIP: 0010:__kmalloc_track_caller+0xc2/0x210

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
heikomat pushed a commit that referenced this issue Jul 13, 2019
This reverts commit 5fd4ca2.

Mikhail Gavrilov reports that it causes the VM_BUG_ON_PAGE() in
__delete_from_swap_cache() to trigger:

   page:ffffd6d34dff0000 refcount:1 mapcount:1 mapping:ffff97812323a689 index:0xfecec363
   anon
   flags: 0x17fffe00080034(uptodate|lru|active|swapbacked)
   raw: 0017fffe00080034 ffffd6d34c67c508 ffffd6d3504b8d48 ffff97812323a689
   raw: 00000000fecec363 0000000000000000 0000000100000000 ffff978433ace000
   page dumped because: VM_BUG_ON_PAGE(entry != page)
   page->mem_cgroup:ffff978433ace000
   ------------[ cut here ]------------
   kernel BUG at mm/swap_state.c:170!
   invalid opcode: 0000 [#1] SMP NOPTI
   CPU: 1 PID: 221 Comm: kswapd0 Not tainted 5.2.0-0.rc2.git0.1.fc31.x86_64 #1
   Hardware name: System manufacturer System Product Name/ROG STRIX X470-I GAMING, BIOS 2202 04/11/2019
   RIP: 0010:__delete_from_swap_cache+0x20d/0x240
   Code: 30 65 48 33 04 25 28 00 00 00 75 4a 48 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 2f dc 0f 8a 48 89 c7 e8 93 1b fd ff <0f> 0b 48 c7 c6 a8 74 0f 8a e8 85 1b fd ff 0f 0b 48 c7 c6 a8 7d 0f
   RSP: 0018:ffffa982036e7980 EFLAGS: 00010046
   RAX: 0000000000000021 RBX: 0000000000000040 RCX: 0000000000000006
   RDX: 0000000000000000 RSI: 0000000000000086 RDI: ffff97843d657900
   RBP: 0000000000000001 R08: ffffa982036e7835 R09: 0000000000000535
   R10: ffff97845e21a46c R11: ffffa982036e7835 R12: ffff978426387120
   R13: 0000000000000000 R14: ffffd6d34dff0040 R15: ffffd6d34dff0000
   FS:  0000000000000000(0000) GS:ffff97843d640000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00002cba88ef5000 CR3: 000000078a97c000 CR4: 00000000003406e0
   Call Trace:
    delete_from_swap_cache+0x46/0xa0
    try_to_free_swap+0xbc/0x110
    swap_writepage+0x13/0x70
    pageout.isra.0+0x13c/0x350
    shrink_page_list+0xc14/0xdf0
    shrink_inactive_list+0x1e5/0x3c0
    shrink_node_memcg+0x202/0x760
    shrink_node+0xe0/0x470
    balance_pgdat+0x2d1/0x510
    kswapd+0x220/0x420
    kthread+0xfb/0x130
    ret_from_fork+0x22/0x40

and it's not immediately obvious why it happens.  It's too late in the
rc cycle to do anything but revert for now.

Link: https://lore.kernel.org/lkml/CABXGCsN9mYmBD-4GaaeW_NrDu+FDXLzr_6x+XNxfmFV6QkYCDg@mail.gmail.com/
Reported-and-bisected-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Suggested-by: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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