{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "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 (&tbl->lock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652\n  [...]\n  but task is already holding lock:\n  ffffffff8d4dd370 (&tbl->lock){++-.}-{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] <TASK>\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  </TASK>"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "include/net/neighbour.h",
                  "net/core/neighbour.c"
               ],
               "versions": [
                  {
                     "version": "7482e3841d52",
                     "lessThan": "203a35ebb49c",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "7482e3841d52",
                     "lessThan": "4a81f6da9cb2",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "include/net/neighbour.h",
                  "net/core/neighbour.c"
               ],
               "versions": [
                  {
                     "version": "5.16",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.16",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16.8",
                     "lessThanOrEqual": "5.16.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.17",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/203a35ebb49cdce377416b0690215d3ce090d364"
            },
            {
               "url": "https://git.kernel.org/stable/c/4a81f6da9cb2d1ef911131a6fd8bd15cb61fc772"
            }
         ],
         "title": "net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work",
         "x_generator": {
            "engine": "bippy-7d53e8ef8be4"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2022-48719",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}