ghsa-6j4r-jvg8-v6gc
Vulnerability from github
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]
{
"affected": [],
"aliases": [
"CVE-2022-48719"
],
"database_specific": {
"cwe_ids": [
"CWE-667"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-20T11:15:55Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work\n\nsyzkaller was able to trigger a deadlock for NTF_MANAGED entries [0]:\n\n kworker/0:16/14617 is trying to acquire lock:\n ffffffff8d4dd370 (\u0026tbl-\u003elock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652\n [...]\n but task is already holding lock:\n ffffffff8d4dd370 (\u0026tbl-\u003elock){++-.}-{2:2}, at: neigh_managed_work+0x35/0x250 net/core/neighbour.c:1572\n\nThe neighbor entry turned to NUD_FAILED state, where __neigh_event_send()\ntriggered an immediate probe as per commit cd28ca0a3dd1 (\"neigh: reduce\narp latency\") via neigh_probe() given table lock was held.\n\nOne option to fix this situation is to defer the neigh_probe() back to\nthe neigh_timer_handler() similarly as pre cd28ca0a3dd1. For the case\nof NTF_MANAGED, this deferral is acceptable given this only happens on\nactual failure state and regular / expected state is NUD_VALID with the\nentry already present.\n\nThe fix adds a parameter to __neigh_event_send() in order to communicate\nwhether immediate probe is allowed or disallowed. Existing call-sites\nof neigh_event_send() default as-is to immediate probe. However, the\nneigh_managed_work() disables it via use of neigh_event_send_probe().\n\n[0] \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]\n check_deadlock kernel/locking/lockdep.c:2999 [inline]\n validate_chain kernel/locking/lockdep.c:3788 [inline]\n __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027\n lock_acquire kernel/locking/lockdep.c:5639 [inline]\n lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604\n __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline]\n _raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:334\n ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652\n ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123\n __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]\n __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170\n ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201\n NF_HOOK_COND include/linux/netfilter.h:296 [inline]\n ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224\n dst_output include/net/dst.h:451 [inline]\n NF_HOOK include/linux/netfilter.h:307 [inline]\n ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508\n ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650\n ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:742\n neigh_probe+0xc2/0x110 net/core/neighbour.c:1040\n __neigh_event_send+0x37d/0x1570 net/core/neighbour.c:1201\n neigh_event_send include/net/neighbour.h:470 [inline]\n neigh_managed_work+0x162/0x250 net/core/neighbour.c:1574\n process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307\n worker_thread+0x657/0x1110 kernel/workqueue.c:2454\n kthread+0x2e9/0x3a0 kernel/kthread.c:377\n ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295\n \u003c/TASK\u003e",
"id": "GHSA-6j4r-jvg8-v6gc",
"modified": "2024-09-18T18:30:49Z",
"published": "2024-06-20T12:31:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48719"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/203a35ebb49cdce377416b0690215d3ce090d364"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4a81f6da9cb2d1ef911131a6fd8bd15cb61fc772"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}