On 8/16/21 6:56 PM, Marcel Holtmann wrote:
> Hi Pavel,
>
[snip]

> I agree. Feel free to send a patch.
>
Thank you, Marcel! I will send a patch if it will pass syzbot testing.

I believe, 60 seconds will be more than enough for inquiry request. I've searched for examples on the internet and maximum ir.length I found was 8. Maybe, we have users, which need more than 60 seconds, idk...

#syz test
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

With regards,
Pavel Skripkin

From c868a2f2533bb05873fedcde6bc4ca174f8908ea Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Mon, 16 Aug 2021 22:52:29 +0300
Subject: [PATCH] Bluetooth: add timeout sanity check to hci_inquiry

/* ... */

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>

… enabled

When receiving a new connection pchan->conn won't be initialized so the
code cannot use bt_dev_dbg as the pointer to hci_dev won't be
accessible.

Fixes: 2e1614f ("Bluetooth: SMP: Convert BT_ERR/BT_DBG to bt_dev_err/bt_dev_dbg")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Syzbot reported slab-out-of-bounds Read in
qrtr_endpoint_post. The problem was in wrong
_size_ type:

	if (len != ALIGN(size, 4) + hdrlen)
		goto err;

If size from qrtr_hdr is 4294967293 (0xfffffffd), the result of
ALIGN(size, 4) will be 0. In case of len == hdrlen and size == 4294967293
in header this check won't fail and

	skb_put_data(skb, data + hdrlen, size);

will read out of bound from data, which is hdrlen allocated block.

Fixes: 194ccc8 ("net: qrtr: Support decoding incoming v2 packets")
Reported-and-tested-by: syzbot+1917d778024161609247@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Oliver reported a use case where deleting a VRF device can hang
waiting for the refcnt to drop to 0. The root cause is that the dst
is allocated against the VRF device but cached on the loopback
device.

The use case (added to the selftests) has an implicit VRF crossing
due to the ordering of the FIB rules (lookup local is before the
l3mdev rule, but the problem occurs even if the FIB rules are
re-ordered with local after l3mdev because the VRF table does not
have a default route to terminate the lookup). The end result is
is that the FIB lookup returns the loopback device as the nexthop,
but the ingress device is in a VRF. The mismatch causes the dst
alloc against the VRF device but then cached on the loopback.

The fix is to bring the trick used for IPv6 (see ip6_rt_get_dev_rcu):
pick the dst alloc device based the fib lookup result but with checks
that the result has a nexthop device (e.g., not an unreachable or
prohibit entry).

Fixes: f5a0aab ("net: ipv4: dst for local input routes should use l3mdev if relevant")
Reported-by: Oliver Herms <oliver.peter.herms@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzbot reported memory leak in tty_init_dev().
The problem was in unputted tty in ldisc_open()

static int ldisc_open(struct tty_struct *tty)
{
...
	ser->tty = tty_kref_get(tty);
...
	result = register_netdevice(dev);
	if (result) {
		rtnl_unlock();
		free_netdev(dev);
		return -ENODEV;
	}
...
}

Ser pointer is netdev private_data, so after free_netdev()
this pointer goes away with unputted tty reference. So, fix
it by adding tty_kref_put() before freeing netdev.

Reported-and-tested-by: syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The TID returned during successful filter creation is relative to
the region in which the filter is created. Using it directly always
returns Hi Prio/Normal filter region's entry for the first couple of
entries, even though the rule is actually inserted in Hash region.
Fix by analyzing in which region the filter has been inserted and
save the absolute TID to be used for lookup later.

Fixes: db43b30 ("cxgb4: add ethtool n-tuple filter deletion")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an error occurs after a 'pci_enable_pcie_error_reporting()' call, it
must be undone by a corresponding 'pci_disable_pcie_error_reporting()'
call, as already done in the remove function.

Fixes: e87ad55 ("netxen: support pci error handlers")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an error occurs after a 'pci_enable_pcie_error_reporting()' call, it
must be undone by a corresponding 'pci_disable_pcie_error_reporting()'
call, as already done in the remove function.

Fixes: 451724c ("qlcnic: aer support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Outer nest for ETHTOOL_A_STRSET_STRINGSETS is not accounted for.
This may result in ETHTOOL_MSG_STRSET_GET producing a warning like:

    calculated message payload length (684) not sufficient
    WARNING: CPU: 0 PID: 30967 at net/ethtool/netlink.c:369 ethnl_default_doit+0x87a/0xa20

and a splat.

As usually with such warnings three conditions must be met for the warning
to trigger:
 - there must be no skb size rounding up (e.g. reply_size of 684);
 - string set must be per-device (so that the header gets populated);
 - the device name must be at least 12 characters long.

all in all with current user space it looks like reading priv flags
is the only place this could potentially happen. Or with syzbot :)

Reported-by: syzbot+59aa77b92d06cd5a54f2@syzkaller.appspotmail.com
Fixes: 7192169 ("ethtool: provide string sets with STRSET_GET request")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The purpose of the loop using u64_stats_fetch_*_irq() is to ensure
statistics on a given CPU are collected atomically. If one of the
statistics values gets updated within the begin/retry window, the
loop will run again.

Currently the statistics totals are updated inside that window.
This means that if the loop ever retries, the statistics for the
CPU will be counted more than once.

Fix this by taking a snapshot of a CPU's statistics inside the
protected window, and then updating the counters with the snapshot
values after exiting the loop.

(Also add a newline at the end of this file...)

Fixes: 192c4b5 ("net: qualcomm: rmnet: Add support for 64 bit stats")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit b839280 ("sch_cake: add RFC 8622 LE PHB support to CAKE
diffserv handling") added the LE mark to the Bulk tin. Update the
comments to reflect the change.

Signed-off-by: Tyson Moore <tyson@tyson.me>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled.
The reason is that nsfs tries to access ns->ops but the proc_ns_operations
is not implemented in this case.

[7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010
[7.670268] pgd = 32b54000
[7.670544] [00000010] *pgd=00000000
[7.671861] Internal error: Oops: 5 [#1] SMP ARM
[7.672315] Modules linked in:
[7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 torvalds#16
[7.673309] Hardware name: Generic DT based system
[7.673642] PC is at nsfs_evict+0x24/0x30
[7.674486] LR is at clear_inode+0x20/0x9c

The same to tun SIOCGSKNS command.

To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is
disabled. Meanwhile move it to right place net/core/net_namespace.c.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: c62cce2 ("net: add an ioctl to get a socket network namespace")
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The register starts from 0x800 is the 16th MAC address register rather
than the first one.

Fixes: cffb13f ("stmmac: extend mac addr reg and fix perfect filering")
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rahul Lakkireddy says:

====================
cxgb4: bug fixes for ethtool flash ops

This series of patches add bug fixes in ethtool flash operations.

Patch 1 fixes an endianness issue when writing boot image to flash
after the device ID has been updated.

Patch 2 fixes sleep in atomic when writing PHY firmware to flash.

Patch 3 fixes issue with PHY firmware image not getting written to
flash when chip is still running.
-====================

Signed-off-by: David S. Miller <davem@davemloft.net>

When using firmware-assisted PHY firmware image write to flash,
halt the chip before beginning the flash write operation to allow
the running firmware to store the image persistently. Otherwise,
the running firmware will only store the PHY image in local on-chip
RAM, which will be lost after next reset.

Fixes: 4ee339e ("cxgb4: add support to flash PHY image")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before writing new PHY firmware to on-chip memory, driver queries
firmware for current running PHY firmware version, which can result
in sleep waiting for reply. So, move spinlock closer to the actual
on-chip memory write operation, instead of taking it at the callers.

Fixes: 5fff701 ("cxgb4: always sync access when flashing PHY firmware")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Boot images are copied to memory and updated with current underlying
device ID before flashing them to adapter. Ensure the updated images
are always flashed in Big Endian to allow the firmware to read the
new images during boot properly.

Fixes: 5508835 ("cxgb4: add support to flash boot image")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an error occurs after a 'pci_enable_pcie_error_reporting()' call, it
must be undone by a corresponding 'pci_disable_pcie_error_reporting()'
call, as already done in the remove function.

Fixes: ab69bde ("alx: add a simple AR816x/AR817x device driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Current logic is performing hard reset and causing the programmed
registers to be wiped out.

as per datasheet: https://www.ti.com/lit/ds/symlink/dp83867cr.pdf
8.6.26 Control Register (CTRL)

do SW_RESTART to perform a reset not including the registers,
If performed when link is already present,
it will drop the link and trigger re-auto negotiation.

Signed-off-by: Praneeth Bajjuri <praneeth@ti.com>
Signed-off-by: Geet Modi <geet.modi@ti.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mat Martineau says:

====================
mptcp: More v5.13 fixes

Here's another batch of MPTCP fixes for v5.13.

Patch 1 cleans up memory accounting between the MPTCP-level socket and
the subflows to more reliably transfer forward allocated memory under
pressure.

Patch 2 wakes up socket readers more reliably.

Patch 3 changes a WARN_ONCE to a pr_debug.

Patch 4 changes the selftests to only use syncookies in test cases where
they do not cause spurious failures.

Patch 5 modifies socket error reporting to avoid a possible soft lockup.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Maxim reported a soft lookup in subflow_error_report():

 watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0]
 RIP: 0010:native_queued_spin_lock_slowpath
 RSP: 0018:ffffa859c0003bc0 EFLAGS: 00000202
 RAX: 0000000000000101 RBX: 0000000000000001 RCX: 0000000000000000
 RDX: ffff9195c2772d88 RSI: 0000000000000000 RDI: ffff9195c2772d88
 RBP: ffff9195c2772d00 R08: 00000000000067b0 R09: c6e31da9eb1e44f4
 R10: ffff9195ef379700 R11: ffff9195edb50710 R12: ffff9195c2772d88
 R13: ffff9195f500e3d0 R14: ffff9195ef379700 R15: ffff9195ef379700
 FS:  0000000000000000(0000) GS:ffff91961f400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000000c000407000 CR3: 0000000002988000 CR4: 00000000000006f0
 Call Trace:
  <IRQ>
 _raw_spin_lock_bh
 subflow_error_report
 mptcp_subflow_data_available
 __mptcp_move_skbs_from_subflow
 mptcp_data_ready
 tcp_data_queue
 tcp_rcv_established
 tcp_v4_do_rcv
 tcp_v4_rcv
 ip_protocol_deliver_rcu
 ip_local_deliver_finish
 __netif_receive_skb_one_core
 netif_receive_skb
 rtl8139_poll 8139too
 __napi_poll
 net_rx_action
 __do_softirq
 __irq_exit_rcu
 common_interrupt
  </IRQ>

The calling function - mptcp_subflow_data_available() - can be invoked
from different contexts:
- plain ssk socket lock
- ssk socket lock + mptcp_data_lock
- ssk socket lock + mptcp_data_lock + msk socket lock.

Since subflow_error_report() tries to acquire the mptcp_data_lock, the
latter two call chains will cause soft lookup.

This change addresses the issue moving the error reporting call to
outer functions, where the held locks list is known and the we can
acquire only the needed one.

Reported-by: Maxim Galaganov <max@internet.ru>
Fixes: 15cc104 ("mptcp: deliver ssk errors to msk")
Closes: multipath-tcp/mptcp_net-next#199
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Syncookie validation may fail for OoO packets, causing spurious
resets and self-tests failures, so let's force syncookie only
for tests iteration with no OoO.

Fixes: fed61c4 ("selftests: mptcp: make 2nd net namespace use tcp syn cookies unconditionally")
Closes: multipath-tcp/mptcp_net-next#198
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

warn_bad_map() produces a kernel WARN on bad input coming
from the network. Use pr_debug() to avoid spamming the system
log.

Additionally, when the right bound check fails, warn_bad_map() reports
the wrong ssn value, let's fix it.

Fixes: 648ef4b ("mptcp: Implement MPTCP receive path")
Closes: multipath-tcp/mptcp_net-next#107
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently we rely on the subflow->data_avail field, which is subject to
races:

	ssk1
		skb len = 500 DSS(seq=1, len=1000, off=0)
		# data_avail == MPTCP_SUBFLOW_DATA_AVAIL

	ssk2
		skb len = 500 DSS(seq = 501, len=1000)
		# data_avail == MPTCP_SUBFLOW_DATA_AVAIL

	ssk1
		skb len = 500 DSS(seq = 1, len=1000, off =500)
		# still data_avail == MPTCP_SUBFLOW_DATA_AVAIL,
		# as the skb is covered by a pre-existing map,
		# which was in-sequence at reception time.

Instead we can explicitly check if some has been received in-sequence,
propagating the info from __mptcp_move_skbs_from_subflow().

Additionally add the 'ONCE' annotation to the 'data_avail' memory
access, as msk will read it outside the subflow socket lock.

Fixes: 648ef4b ("mptcp: Implement MPTCP receive path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the host is under sever memory pressure, and RX forward
memory allocation for the msk fails, we try to borrow the
required memory from the ingress subflow.

The current attempt is a bit flaky: if skb->truesize is less
than SK_MEM_QUANTUM, the ssk will not release any memory, and
the next schedule will fail again.

Instead, directly move the required amount of pages from the
ssk to the msk, if available

Fixes: 9c3f94e ("mptcp: add missing memory scheduling in the rx path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Fix a crash when stateful expression with its own gc callback
   is used in a set definition.

2) Skip IPv6 packets from any link-local address in IPv6 fib expression.
   Add a selftest for this scenario, from Florian Westphal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Maxim Mikityanskiy says:

====================
Fix out of bounds when parsing TCP options

This series fixes out-of-bounds access in various places in the kernel
where parsing of TCP options takes place. Fortunately, many more
occurrences don't have this bug.

v2 changes:

synproxy: Added an early return when length < 0 to avoid calling
skb_header_pointer with negative length.

sch_cake: Added doff validation to avoid parsing garbage.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

The TCP option parser in cake qdisc (cake_get_tcpopt and
cake_tcph_may_drop) could read one byte out of bounds. When the length
is 1, the execution flow gets into the loop, reads one byte of the
opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads
one more byte, which exceeds the length of 1.

This fix is inspired by commit 9609dad ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").

v2 changes:

Added doff validation in cake_get_tcphdr to avoid parsing garbage as TCP
header. Although it wasn't strictly an out-of-bounds access (memory was
allocated), garbage values could be read where CAKE expected the TCP
header if doff was smaller than 5.

Cc: Young Xiao <92siuyang@gmail.com>
Fixes: 8b71388 ("sch_cake: Add optional ACK filter")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

The TCP option parser in mptcp (mptcp_get_options) could read one byte
out of bounds. When the length is 1, the execution flow gets into the
loop, reads one byte of the opcode, and if the opcode is neither
TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the
length of 1.

This fix is inspired by commit 9609dad ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").

Cc: Young Xiao <92siuyang@gmail.com>
Fixes: cec37a6 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The TCP option parser in synproxy (synproxy_parse_options) could read
one byte out of bounds. When the length is 1, the execution flow gets
into the loop, reads one byte of the opcode, and if the opcode is
neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds
the length of 1.

This fix is inspired by commit 9609dad ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").

v2 changes:

Added an early return when length < 0 to avoid calling
skb_header_pointer with negative length.

Cc: Young Xiao <92siuyang@gmail.com>
Fixes: 48b1de4 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a known race in packet_sendmsg(), addressed
in commit 32d3182 ("net/packet: fix race in tpacket_snd()")

Now we have data_race(), we can use it to avoid a future KCSAN warning,
as syzbot loves stressing af_packet sockets :)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

UDP sendmsg() path can be lockless, it is possible for another
thread to re-connect an change sk->sk_txhash under us.

There is no serious impact, but we can use READ_ONCE()/WRITE_ONCE()
pair to document the race.

BUG: KCSAN: data-race in __ip4_datagram_connect / skb_set_owner_w

write to 0xffff88813397920c of 4 bytes by task 30997 on cpu 1:
 sk_set_txhash include/net/sock.h:1937 [inline]
 __ip4_datagram_connect+0x69e/0x710 net/ipv4/datagram.c:75
 __ip6_datagram_connect+0x551/0x840 net/ipv6/datagram.c:189
 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272
 inet_dgram_connect+0xfd/0x180 net/ipv4/af_inet.c:580
 __sys_connect_file net/socket.c:1837 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1854
 __do_sys_connect net/socket.c:1864 [inline]
 __se_sys_connect net/socket.c:1861 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1861
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813397920c of 4 bytes by task 31039 on cpu 0:
 skb_set_hash_from_sk include/net/sock.h:2211 [inline]
 skb_set_owner_w+0x118/0x220 net/core/sock.c:2101
 sock_alloc_send_pskb+0x452/0x4e0 net/core/sock.c:2359
 sock_alloc_send_skb+0x2d/0x40 net/core/sock.c:2373
 __ip6_append_data+0x1743/0x21a0 net/ipv6/ip6_output.c:1621
 ip6_make_skb+0x258/0x420 net/ipv6/ip6_output.c:1983
 udpv6_sendmsg+0x160a/0x16b0 net/ipv6/udp.c:1527
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xbca3c43d -> 0xfdb309e0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31039 Comm: syz-executor.2 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sock_error() is known to be racy. The code avoids
an atomic operation is sk_err is zero, and this field
could be changed under us, this is fine.

Sysbot reported:

BUG: KCSAN: data-race in sock_alloc_send_pskb / unix_release_sock

write to 0xffff888131855630 of 4 bytes by task 9365 on cpu 1:
 unix_release_sock+0x2e9/0x6e0 net/unix/af_unix.c:550
 unix_release+0x2f/0x50 net/unix/af_unix.c:859
 __sock_release net/socket.c:599 [inline]
 sock_close+0x6c/0x150 net/socket.c:1258
 __fput+0x25b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888131855630 of 4 bytes by task 9385 on cpu 0:
 sock_error include/net/sock.h:2269 [inline]
 sock_alloc_send_pskb+0xe4/0x4e0 net/core/sock.c:2336
 unix_dgram_sendmsg+0x478/0x1610 net/unix/af_unix.c:1671
 unix_seqpacket_sendmsg+0xc2/0x100 net/unix/af_unix.c:2055
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 __sys_sendmsg_sock+0x25/0x30 net/socket.c:2416
 io_sendmsg fs/io_uring.c:4367 [inline]
 io_issue_sqe+0x231a/0x6750 fs/io_uring.c:6135
 __io_queue_sqe+0xe9/0x360 fs/io_uring.c:6414
 __io_req_task_submit fs/io_uring.c:2039 [inline]
 io_async_task_func+0x312/0x590 fs/io_uring.c:5074
 __tctx_task_work fs/io_uring.c:1910 [inline]
 tctx_task_work+0x1d4/0x3d0 fs/io_uring.c:1924
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:212 [inline]
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0xf8/0x190 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000068

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9385 Comm: syz-executor.3 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Nikolay Aleksandrov says:

====================
net: bridge: vlan tunnel egress path fixes

These two fixes take care of tunnel_dst problems in the vlan tunnel egress
path. Patch 01 fixes a null ptr deref due to the lockless use of tunnel_dst
pointer without checking it first, and patch 02 fixes a use-after-free
issue due to wrong dst refcounting (dst_clone() -> dst_hold_safe()).

Both fix the same commit and should be queued for stable backports:
Fixes: 11538d0 ("bridge: vlan dst_metadata hooks in ingress and egress paths")

v2: no changes, added stable list to CC
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

The egress tunnel code uses dst_clone() and directly sets the result
which is wrong because the entry might have 0 refcnt or be already deleted,
causing number of problems. It also triggers the WARN_ON() in dst_hold()[1]
when a refcnt couldn't be taken. Fix it by using dst_hold_safe() and
checking if a reference was actually taken before setting the dst.

[1] dmesg WARN_ON log and following refcnt errors
 WARNING: CPU: 5 PID: 38 at include/net/dst.h:230 br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Modules linked in: 8021q garp mrp bridge stp llc bonding ipv6 virtio_net
 CPU: 5 PID: 38 Comm: ksoftirqd/5 Kdump: loaded Tainted: G        W         5.13.0-rc3+ torvalds#360
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
 RIP: 0010:br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Code: e8 85 bc 01 e1 45 84 f6 74 90 45 31 f6 85 db 48 c7 c7 a0 02 19 a0 41 0f 94 c6 31 c9 31 d2 44 89 f6 e8 64 bc 01 e1 85 db 75 02 <0f> 0b 31 c9 31 d2 44 89 f6 48 c7 c7 70 02 19 a0 e8 4b bc 01 e1 49
 RSP: 0018:ffff8881003d39e8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa01902a0
 RBP: ffff8881040c6700 R08: 0000000000000000 R09: 0000000000000001
 R10: 2ce93d0054fe0d00 R11: 54fe0d00000e0000 R12: ffff888109515000
 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000401
 FS:  0000000000000000(0000) GS:ffff88822bf40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f42ba70f030 CR3: 0000000109926000 CR4: 00000000000006e0
 Call Trace:
  br_handle_vlan+0xbc/0xca [bridge]
  __br_forward+0x23/0x164 [bridge]
  deliver_clone+0x41/0x48 [bridge]
  br_handle_frame_finish+0x36f/0x3aa [bridge]
  ? skb_dst+0x2e/0x38 [bridge]
  ? br_handle_ingress_vlan_tunnel+0x3e/0x1c8 [bridge]
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  br_handle_frame+0x2c3/0x377 [bridge]
  ? __skb_pull+0x33/0x51
  ? vlan_do_receive+0x4f/0x36a
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  __netif_receive_skb_core+0x539/0x7c6
  ? __list_del_entry_valid+0x16e/0x1c2
  __netif_receive_skb_list_core+0x6d/0xd6
  netif_receive_skb_list_internal+0x1d9/0x1fa
  gro_normal_list+0x22/0x3e
  dev_gro_receive+0x55b/0x600
  ? detach_buf_split+0x58/0x140
  napi_gro_receive+0x94/0x12e
  virtnet_poll+0x15d/0x315 [virtio_net]
  __napi_poll+0x2c/0x1c9
  net_rx_action+0xe6/0x1fb
  __do_softirq+0x115/0x2d8
  run_ksoftirqd+0x18/0x20
  smpboot_thread_fn+0x183/0x19c
  ? smpboot_unregister_percpu_thread+0x66/0x66
  kthread+0x10a/0x10f
  ? kthread_mod_delayed_work+0xb6/0xb6
  ret_from_fork+0x22/0x30
 ---[ end trace 49f61b07f775fd2b ]---
 dst_release: dst:00000000c02d677a refcnt:-1
 dst_release underflow

Cc: stable@vger.kernel.org
Fixes: 11538d0 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>