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Add sultan's devfreq boost and prevent userspace from set min freq #10

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merged 2 commits into from Sep 11, 2022

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Signed-off-by: Sultan Alsawaf sultan@kerneltoast.com
Signed-off-by: Danny Lin danny@kdrag0n.dev

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
@andreock andreock merged commit 2f89bf8 into 4.19.157-CAF Sep 11, 2022
@andreock andreock deleted the Fix-Sultan-Devfreq-Boost branch September 11, 2022 21:06
andreock pushed a commit that referenced this pull request Oct 14, 2022
A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the
reference for a node. In this case, the target proc normally releases
the failed reference upon close as expected. However, if the target is
dying in parallel the call will race with binder_deferred_release(), so
the target could have released all of its references by now leaving the
cleanup of the new failed reference unhandled.

The transaction then ends and the target proc gets released making the
ref->proc now a dangling pointer. Later on, ref->node is closed and we
attempt to take spin_lock(&ref->proc->inner_lock), which leads to the
use-after-free bug reported below. Let's fix this by cleaning up the
failed reference on the spot instead of relying on the target to do so.

  ==================================================================
  BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150
  Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590

  CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10
  Hardware name: linux,dummy-virt (DT)
  Workqueue: events binder_deferred_func
  Call trace:
   dump_backtrace.part.0+0x1d0/0x1e0
   show_stack+0x18/0x70
   dump_stack_lvl+0x68/0x84
   print_report+0x2e4/0x61c
   kasan_report+0xa4/0x110
   kasan_check_range+0xfc/0x1a4
   __kasan_check_write+0x3c/0x50
   _raw_spin_lock+0xa8/0x150
   binder_deferred_func+0x5e0/0x9b0
   process_one_work+0x38c/0x5f0
   worker_thread+0x9c/0x694
   kthread+0x188/0x190
   ret_from_fork+0x10/0x20

Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>

Bug: 239630375
Link: https://lore.kernel.org/all/20220801182511.3371447-1-cmllamas@google.com/
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Change-Id: I5085dd0dc805a780a64c057e5819f82dd8f02868
(cherry picked from commit ae3fa5d16a02ba7c7b170e0e1ab56d6f0ba33964)
Git-commit: 70f060f
Git-repo: https://android.googlesource.com/kernel/common
Signed-off-by: PavanKumar S.R <quic_pavasr@quicinc.com>
andreock pushed a commit that referenced this pull request Nov 23, 2022
commit 57f0ff059e3daa4e70a811cb1d31a49968262d20 upstream.

It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  OnePlusOSS#17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  OnePlusOSS#18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
CC: Milian Wolff <milian.wolff@kdab.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com
Reported-by: Juri Lelli <jlelli@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
andreock pushed a commit that referenced this pull request Nov 23, 2022
[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ]

When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    OnePlusOSS#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    OnePlusOSS#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    OnePlusOSS#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    OnePlusOSS#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    OnePlusOSS#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    OnePlusOSS#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    OnePlusOSS#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    OnePlusOSS#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    OnePlusOSS#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    OnePlusOSS#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
andreock pushed a commit that referenced this pull request Nov 23, 2022
[ Upstream commit 6b9dbedbe3499fef862c4dff5217cf91f34e43b3 ]

pty_write() invokes kmalloc() which may invoke a normal printk() to print
failure message.  This can cause a deadlock in the scenario reported by
syz-bot below:

       CPU0              CPU1                    CPU2
       ----              ----                    ----
                         lock(console_owner);
                                                 lock(&port_lock_key);
  lock(&port->lock);
                         lock(&port_lock_key);
                                                 lock(&port->lock);
  lock(console_owner);

As commit dbdda84 ("printk: Add console owner and waiter logic to
load balance console writes") said, such deadlock can be prevented by
using printk_deferred() in kmalloc() (which is invoked in the section
guarded by the port->lock).  But there are too many printk() on the
kmalloc() path, and kmalloc() can be called from anywhere, so changing
printk() to printk_deferred() is too complicated and inelegant.

Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so
that printk() will not be called, and this deadlock problem can be
avoided.

Syzbot reported the following lockdep error:

======================================================
WARNING: possible circular locking dependency detected
5.4.143-00237-g08ccc19a-dirty #10 Not tainted
------------------------------------------------------
syz-executor.4/29420 is trying to acquire lock:
ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline]
ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023

but task is already holding lock:
ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&port->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
       tty_port_tty_get drivers/tty/tty_port.c:288 [inline]          		<-- lock(&port->lock);
       tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47
       serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767
       serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854
       serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] 	<-- lock(&port_lock_key);
       serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870
       serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156
       [...]

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
       serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198
										<-- lock(&port_lock_key);
       call_console_drivers kernel/printk/printk.c:1819 [inline]
       console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504
       vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024			<-- lock(console_owner);
       vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394
       printk+0xba/0xed kernel/printk/printk.c:2084
       register_console+0x8b3/0xc10 kernel/printk/printk.c:2829
       univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681
       console_init+0x49d/0x6d3 kernel/printk/printk.c:2915
       start_kernel+0x5e9/0x879 init/main.c:713
       secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

-> #0 (console_owner){....}-{0:0}:
       [...]
       lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734
       console_trylock_spinning kernel/printk/printk.c:1773 [inline]		<-- lock(console_owner);
       vprintk_emit+0x307/0x470 kernel/printk/printk.c:2023
       vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394
       printk+0xba/0xed kernel/printk/printk.c:2084
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x67b/0x7c0 lib/fault-inject.c:144
       __should_failslab+0x152/0x1c0 mm/failslab.c:33
       should_failslab+0x5/0x10 mm/slab_common.c:1224
       slab_pre_alloc_hook mm/slab.h:468 [inline]
       slab_alloc_node mm/slub.c:2723 [inline]
       slab_alloc mm/slub.c:2807 [inline]
       __kmalloc+0x72/0x300 mm/slub.c:3871
       kmalloc include/linux/slab.h:582 [inline]
       tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:175
       __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:273
       tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:318
       tty_insert_flip_string include/linux/tty_flip.h:37 [inline]
       pty_write+0x126/0x1f0 drivers/tty/pty.c:122				<-- lock(&port->lock);
       n_tty_write+0xa7a/0xfc0 drivers/tty/n_tty.c:2356
       do_tty_write drivers/tty/tty_io.c:961 [inline]
       tty_write+0x512/0x930 drivers/tty/tty_io.c:1045
       __vfs_write+0x76/0x100 fs/read_write.c:494
       [...]

other info that might help us debug this:

Chain exists of:
  console_owner --> &port_lock_key --> &port->lock

Link: https://lkml.kernel.org/r/20220511061951.1114-2-zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/20220510113809.80626-2-zhengqi.arch@bytedance.com
Fixes: b6da31b ("tty: Fix data race in tty_insert_flip_string_fixed_flag")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
andreock pushed a commit that referenced this pull request Nov 24, 2022
commit a0e44c64b6061dda7e00b7c458e4523e2331b739 upstream.

A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the
reference for a node. In this case, the target proc normally releases
the failed reference upon close as expected. However, if the target is
dying in parallel the call will race with binder_deferred_release(), so
the target could have released all of its references by now leaving the
cleanup of the new failed reference unhandled.

The transaction then ends and the target proc gets released making the
ref->proc now a dangling pointer. Later on, ref->node is closed and we
attempt to take spin_lock(&ref->proc->inner_lock), which leads to the
use-after-free bug reported below. Let's fix this by cleaning up the
failed reference on the spot instead of relying on the target to do so.

  ==================================================================
  BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150
  Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590

  CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10
  Hardware name: linux,dummy-virt (DT)
  Workqueue: events binder_deferred_func
  Call trace:
   dump_backtrace.part.0+0x1d0/0x1e0
   show_stack+0x18/0x70
   dump_stack_lvl+0x68/0x84
   print_report+0x2e4/0x61c
   kasan_report+0xa4/0x110
   kasan_check_range+0xfc/0x1a4
   __kasan_check_write+0x3c/0x50
   _raw_spin_lock+0xa8/0x150
   binder_deferred_func+0x5e0/0x9b0
   process_one_work+0x38c/0x5f0
   worker_thread+0x9c/0x694
   kthread+0x188/0x190
   ret_from_fork+0x10/0x20

Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Cc: stable <stable@kernel.org> # 4.14+
Link: https://lore.kernel.org/r/20220801182511.3371447-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
andreock pushed a commit that referenced this pull request Jan 30, 2023
A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the
reference for a node. In this case, the target proc normally releases
the failed reference upon close as expected. However, if the target is
dying in parallel the call will race with binder_deferred_release(), so
the target could have released all of its references by now leaving the
cleanup of the new failed reference unhandled.

The transaction then ends and the target proc gets released making the
ref->proc now a dangling pointer. Later on, ref->node is closed and we
attempt to take spin_lock(&ref->proc->inner_lock), which leads to the
use-after-free bug reported below. Let's fix this by cleaning up the
failed reference on the spot instead of relying on the target to do so.

  ==================================================================
  BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150
  Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590

  CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10
  Hardware name: linux,dummy-virt (DT)
  Workqueue: events binder_deferred_func
  Call trace:
   dump_backtrace.part.0+0x1d0/0x1e0
   show_stack+0x18/0x70
   dump_stack_lvl+0x68/0x84
   print_report+0x2e4/0x61c
   kasan_report+0xa4/0x110
   kasan_check_range+0xfc/0x1a4
   __kasan_check_write+0x3c/0x50
   _raw_spin_lock+0xa8/0x150
   binder_deferred_func+0x5e0/0x9b0
   process_one_work+0x38c/0x5f0
   worker_thread+0x9c/0x694
   kthread+0x188/0x190
   ret_from_fork+0x10/0x20

Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>

Bug: 239630375
Link: https://lore.kernel.org/all/20220801182511.3371447-1-cmllamas@google.com/
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Change-Id: I5085dd0dc805a780a64c057e5819f82dd8f02868
(cherry picked from commit ae3fa5d16a02ba7c7b170e0e1ab56d6f0ba33964)
Git-commit: 70f060f
Git-repo: https://android.googlesource.com/kernel/common
Signed-off-by: PavanKumar S.R <quic_pavasr@quicinc.com>
andreock pushed a commit that referenced this pull request Mar 10, 2023
…g the sock

[ Upstream commit 3cf7203ca620682165706f70a1b12b5194607dce ]

There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.

   #0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
   #1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
   #2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
   #3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
   #4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
   #5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
   #6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
      [exception RIP: vxlan_ecn_decapsulate+0x3b]
      RIP: ffffffffc1014e7b  RSP: ffffa25ec6978cb0  RFLAGS: 00010246
      RAX: 0000000000000008  RBX: ffff8aa000888000  RCX: 0000000000000000
      RDX: 000000000000000e  RSI: ffff8a9fc7ab803e  RDI: ffff8a9fd1168700
      RBP: ffff8a9fc7ab803e   R8: 0000000000700000   R9: 00000000000010ae
      R10: ffff8a9fcb748980  R11: 0000000000000000  R12: ffff8a9fd1168700
      R13: ffff8aa000888000  R14: 00000000002a0000  R15: 00000000000010ae
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   #7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
   #8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
   #9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
  #10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
  #11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
  #12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
  #13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
  #14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
  #15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
  #16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
  OnePlusOSS#17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
  OnePlusOSS#18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3

Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh

Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.

Reported-by: Jianlin Shi <jishi@redhat.com>
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Fixes: 6a93cc9 ("udp-tunnel: Add a few more UDP tunnel APIs")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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