ghsa-6j4r-jvg8-v6gc
Vulnerability from github
Published
2024-06-20 12:31
Modified
2024-09-18 18:30
Details

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 neighcreate+0x9e1/0x2990 net/core/neighbour.c:652 ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123 ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650 ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:742 neigh_probe+0xc2/0x110 net/core/neighbour.c:1040 __neigh_event_send+0x37d/0x1570 net/core/neighbour.c:1201 neigh_event_send include/net/neighbour.h:470 [inline] neigh_managed_work+0x162/0x250 net/core/neighbour.c:1574 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Show details on source website


{
  "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"
    }
  ]
}


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