ghsa-p46c-p6jp-xfpq
Vulnerability from github
Published
2024-07-12 15:31
Modified
2024-09-19 15:30
Severity ?
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Details

In the Linux kernel, the following vulnerability has been resolved:

ipv6: fix possible race in __fib6_drop_pcpu_from()

syzbot found a race in __fib6_drop_pcpu_from() [1]

If compiler reads more than once (*ppcpu_rt), second read could read NULL, if another cpu clears the value in rt6_get_pcpu_route().

Add a READ_ONCE() to prevent this race.

Also add rcu_read_lock()/rcu_read_unlock() because we rely on RCU protection while dereferencing pcpu_rt.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: netns cleanup_net RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984 Code: 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 RSP: 0018:ffffc900040df070 EFLAGS: 00010206 RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16 RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007 R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8 R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline] fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline] fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038 fib6_del_route net/ipv6/ip6_fib.c:1998 [inline] fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043 fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175 fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255 __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271 rt6_sync_down_dev net/ipv6/route.c:4906 [inline] rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911 addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855 addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline] call_netdevice_notifiers net/core/dev.c:2044 [inline] dev_close_many+0x333/0x6a0 net/core/dev.c:1585 unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193 unregister_netdevice_many net/core/dev.c:11276 [inline] default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

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{
  "affected": [],
  "aliases": [
    "CVE-2024-40905"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-12T13:15:13Z",
    "severity": "MODERATE"
  },
  "details": "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 \u003c80\u003e 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 \u003cTASK\u003e\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",
  "id": "GHSA-p46c-p6jp-xfpq",
  "modified": "2024-09-19T15:30:48Z",
  "published": "2024-07-12T15:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40905"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/09e5a5a80e205922151136069e440477d6816914"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2498960dac9b6fc49b6d1574f7cd1a4872744adf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7e796c3fefa8b17b30e7252886ae8cffacd2b9ef"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a0bc020592b54a8f3fa2b7f244b6e39e526c2e12"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b01e1c030770ff3b4fe37fc7cc6bca03f594133f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c693698787660c97950bc1f93a8dd19d8307153d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c90af1cced2f669a7b2304584be4ada495eaa0e5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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