Subject: CVE-2023-52578: net: bridge: use DEV_STATS_INC()

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

net: bridge: use DEV_STATS_INC()

syzbot/KCSAN reported data-races in br_handle_frame_finish() [1]
This function can run from multiple cpus without mutual exclusion.

Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.

Handles updates to dev->stats.tx_dropped while we are at it.

[1]
BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish

read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 1:
br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189
br_nf_hook_thresh+0x1ed/0x220
br_nf_pre_routing_finish_ipv6+0x50f/0x540
NF_HOOK include/linux/netfilter.h:304 [inline]
br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178
br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:272 [inline]
br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417
__netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417
__netif_receive_skb_one_core net/core/dev.c:5521 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637
process_backlog+0x21f/0x380 net/core/dev.c:5965
__napi_poll+0x60/0x3b0 net/core/dev.c:6527
napi_poll net/core/dev.c:6594 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6727
__do_softirq+0xc1/0x265 kernel/softirq.c:553
run_ksoftirqd+0x17/0x20 kernel/softirq.c:921
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 0:
br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189
br_nf_hook_thresh+0x1ed/0x220
br_nf_pre_routing_finish_ipv6+0x50f/0x540
NF_HOOK include/linux/netfilter.h:304 [inline]
br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178
br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:272 [inline]
br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417
__netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417
__netif_receive_skb_one_core net/core/dev.c:5521 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637
process_backlog+0x21f/0x380 net/core/dev.c:5965
__napi_poll+0x60/0x3b0 net/core/dev.c:6527
napi_poll net/core/dev.c:6594 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6727
__do_softirq+0xc1/0x265 kernel/softirq.c:553
do_softirq+0x5e/0x90 kernel/softirq.c:454
__local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_tt_local_purge+0x1a8/0x1f0 net/batman-adv/translation-table.c:1356
batadv_tt_purge+0x2b/0x630 net/batman-adv/translation-table.c:3560
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
worker_thread+0x525/0x730 kernel/workqueue.c:2784
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

value changed: 0x00000000000d7190 -> 0x00000000000d7191

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14848 Comm: kworker/u4:11 Not tainted 6.6.0-rc1-syzkaller-00236-gad8a69f361b9 #0

The Linux kernel CVE team has assigned CVE-2023-52578 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 4.19.296 with commit d2346e6beb69
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 5.4.258 with commit ad8d39c7b437
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 5.10.198 with commit 04cc361f029c
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 5.15.134 with commit 8bc97117b51d
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 6.1.56 with commit 89f9f20b1cbd
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 6.5.6 with commit f2ef4cb4d418
	Issue introduced in 2.6.17 with commit 1c29fc4989bc and fixed in 6.6 with commit 44bdb313da57

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-52578
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	net/bridge/br_forward.c
	net/bridge/br_input.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d2346e6beb699909ca455d9d20c4e577ce900839
	https://git.kernel.org/stable/c/ad8d39c7b437fcdab7208a6a56c093d222c008d5
	https://git.kernel.org/stable/c/04cc361f029c14dd067ad180525c7392334c9bfd
	https://git.kernel.org/stable/c/8bc97117b51d68d5cea8f5351cca2d8c4153f394
	https://git.kernel.org/stable/c/89f9f20b1cbd36d99d5a248a4bf8d11d4fd049a2
	https://git.kernel.org/stable/c/f2ef4cb4d418fa64fe73eb84d10cc5c0e52e00fa
	https://git.kernel.org/stable/c/44bdb313da57322c9b3c108eb66981c6ec6509f4