CVE-2022-48719: In the Linux kernel, the following vulnerability has been resolved: net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work syzkaller…

PriorityP420medium5.5CVSS 3.1

AVLACLPRLUINSUCNINAH

EPSS

0.14%

3.9th percentile

In the Linux kernel, the following vulnerability has been resolved: net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work syzkaller was able to trigger a deadlock for NTF_MANAGED entries [0]: kworker/0:16/14617 is trying to acquire lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 [...] but task is already holding lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: neigh_managed_work+0x35/0x250 net/core/neighbour.c:1572 The neighbor entry turned to NUD_FAILED state, where __neigh_event_send() triggered an immediate probe as per commit cd28ca0a3dd1 ("neigh: reduce arp latency") via neigh_probe() given table lock was held. One option to fix this situation is to defer the neigh_probe() back to the neigh_timer_handler() similarly as pre cd28ca0a3dd1. For the case of NTF_MANAGED, this deferral is acceptable given this only happens on actual failure state and regular / expected state is NUD_VALID with the entry already present. The fix adds a parameter to __neigh_event_send() in order to communicate whether immediate probe is allowed or disallowed. Existing call-sites of neigh_event_send() default as-is to immediate probe. However, the neigh_managed_work() disables it via use of neigh_event_send_probe(). [0] __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline] check_deadlock kernel/locking/lockdep.c:2999 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:334 ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123 __ip6_finish_output net/i

Affected

9 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 5.16.10-1 (bookworm)	linux 5.16.10-1 (bookworm)
linux	linux	—	—
linux	linux	>= 7482e3841d520a368426ac196720601687e2dc47 < 203a35ebb49cdce377416b0690215d3ce090d364	203a35ebb49cdce377416b0690215d3ce090d364
linux	linux	>= 7482e3841d520a368426ac196720601687e2dc47 < 4a81f6da9cb2d1ef911131a6fd8bd15cb61fc772	4a81f6da9cb2d1ef911131a6fd8bd15cb61fc772
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 5.16.10-1	5.16.10-1
linux	linux_kernel	>= 0 < 5.16.10-1	5.16.10-1
linux	linux_kernel	>= 0 < 5.16.10-1	5.16.10-1
linux	linux_kernel	>= 5.16 < 5.16.8	5.16.8

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv5.5MEDIUM

vendor_debian5.5MEDIUM

vendor_redhat5.5MEDIUM

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