{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix possible race in __fib6_drop_pcpu_from()\n\nsyzbot found a race in __fib6_drop_pcpu_from() [1]\n\nIf compiler reads more than once (*ppcpu_rt),\nsecond read could read NULL, if another cpu clears\nthe value in rt6_get_pcpu_route().\n\nAdd a READ_ONCE() to prevent this race.\n\nAlso add rcu_read_lock()/rcu_read_unlock() because\nwe rely on RCU protection while dereferencing pcpu_rt.\n\n[1]\n\nOops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]\nCPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024\nWorkqueue: netns cleanup_net\n RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984\nCode: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48\nRSP: 0018:ffffc900040df070 EFLAGS: 00010206\nRAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16\nRDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091\nRBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007\nR10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8\nR13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001\nFS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n  __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline]\n  fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline]\n  fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038\n  fib6_del_route net/ipv6/ip6_fib.c:1998 [inline]\n  fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043\n  fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205\n  fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127\n  fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175\n  fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255\n  __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271\n  rt6_sync_down_dev net/ipv6/route.c:4906 [inline]\n  rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911\n  addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855\n  addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778\n  notifier_call_chain+0xb9/0x410 kernel/notifier.c:93\n  call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992\n  call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]\n  call_netdevice_notifiers net/core/dev.c:2044 [inline]\n  dev_close_many+0x333/0x6a0 net/core/dev.c:1585\n  unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193\n  unregister_netdevice_many net/core/dev.c:11276 [inline]\n  default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759\n  ops_exit_list+0x128/0x180 net/core/net_namespace.c:178\n  cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640\n  process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231\n  process_scheduled_works kernel/workqueue.c:3312 [inline]\n  worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393\n  kthread+0x2c1/0x3a0 kernel/kthread.c:389\n  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/ipv6/ip6_fib.c",
                  "net/ipv6/route.c"
               ],
               "versions": [
                  {
                     "version": "d52d3997f843",
                     "lessThan": "c90af1cced2f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "c69369878766",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "a0bc020592b5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "2498960dac9b",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "7e796c3fefa8",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "09e5a5a80e20",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d52d3997f843",
                     "lessThan": "b01e1c030770",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/ipv6/ip6_fib.c",
                  "net/ipv6/route.c"
               ],
               "versions": [
                  {
                     "version": "4.2",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "4.2",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.4.279",
                     "lessThanOrEqual": "5.4.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.221",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.162",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.95",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.35",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.9.6",
                     "lessThanOrEqual": "6.9.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/c90af1cced2f669a7b2304584be4ada495eaa0e5"
            },
            {
               "url": "https://git.kernel.org/stable/c/c693698787660c97950bc1f93a8dd19d8307153d"
            },
            {
               "url": "https://git.kernel.org/stable/c/a0bc020592b54a8f3fa2b7f244b6e39e526c2e12"
            },
            {
               "url": "https://git.kernel.org/stable/c/2498960dac9b6fc49b6d1574f7cd1a4872744adf"
            },
            {
               "url": "https://git.kernel.org/stable/c/7e796c3fefa8b17b30e7252886ae8cffacd2b9ef"
            },
            {
               "url": "https://git.kernel.org/stable/c/09e5a5a80e205922151136069e440477d6816914"
            },
            {
               "url": "https://git.kernel.org/stable/c/b01e1c030770ff3b4fe37fc7cc6bca03f594133f"
            }
         ],
         "title": "ipv6: fix possible race in __fib6_drop_pcpu_from()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-40905",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}
