nvd-json-data-feeds/CVE-2021/CVE-2021-469xx/CVE-2021-46981.json

{
  "id": "CVE-2021-46981",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-02-28T09:15:37.320",
  "lastModified": "2024-02-28T14:06:45.783",
  "vulnStatus": "Awaiting Analysis",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: Fix NULL pointer in flush_workqueue\n\nOpen /dev/nbdX first, the config_refs will be 1 and\nthe pointers in nbd_device are still null. Disconnect\n/dev/nbdX, then reference a null recv_workq. The\nprotection by config_refs in nbd_genl_disconnect is useless.\n\n[  656.366194] BUG: kernel NULL pointer dereference, address: 0000000000000020\n[  656.368943] #PF: supervisor write access in kernel mode\n[  656.369844] #PF: error_code(0x0002) - not-present page\n[  656.370717] PGD 10cc87067 P4D 10cc87067 PUD 1074b4067 PMD 0\n[  656.371693] Oops: 0002 [#1] SMP\n[  656.372242] CPU: 5 PID: 7977 Comm: nbd-client Not tainted 5.11.0-rc5-00040-g76c057c84d28 #1\n[  656.373661] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014\n[  656.375904] RIP: 0010:mutex_lock+0x29/0x60\n[  656.376627] Code: 00 0f 1f 44 00 00 55 48 89 fd 48 83 05 6f d7 fe 08 01 e8 7a c3 ff ff 48 83 05 6a d7 fe 08 01 31 c0 65 48 8b 14 25 00 6d 01 00 <f0> 48 0f b1 55 d\n[  656.378934] RSP: 0018:ffffc900005eb9b0 EFLAGS: 00010246\n[  656.379350] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000\n[  656.379915] RDX: ffff888104cf2600 RSI: ffffffffaae8f452 RDI: 0000000000000020\n[  656.380473] RBP: 0000000000000020 R08: 0000000000000000 R09: ffff88813bd6b318\n[  656.381039] R10: 00000000000000c7 R11: fefefefefefefeff R12: ffff888102710b40\n[  656.381599] R13: ffffc900005eb9e0 R14: ffffffffb2930680 R15: ffff88810770ef00\n[  656.382166] FS:  00007fdf117ebb40(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000\n[  656.382806] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  656.383261] CR2: 0000000000000020 CR3: 0000000100c84000 CR4: 00000000000006e0\n[  656.383819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[  656.384370] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n[  656.384927] Call Trace:\n[  656.385111]  flush_workqueue+0x92/0x6c0\n[  656.385395]  nbd_disconnect_and_put+0x81/0xd0\n[  656.385716]  nbd_genl_disconnect+0x125/0x2a0\n[  656.386034]  genl_family_rcv_msg_doit.isra.0+0x102/0x1b0\n[  656.386422]  genl_rcv_msg+0xfc/0x2b0\n[  656.386685]  ? nbd_ioctl+0x490/0x490\n[  656.386954]  ? genl_family_rcv_msg_doit.isra.0+0x1b0/0x1b0\n[  656.387354]  netlink_rcv_skb+0x62/0x180\n[  656.387638]  genl_rcv+0x34/0x60\n[  656.387874]  netlink_unicast+0x26d/0x590\n[  656.388162]  netlink_sendmsg+0x398/0x6c0\n[  656.388451]  ? netlink_rcv_skb+0x180/0x180\n[  656.388750]  ____sys_sendmsg+0x1da/0x320\n[  656.389038]  ? ____sys_recvmsg+0x130/0x220\n[  656.389334]  ___sys_sendmsg+0x8e/0xf0\n[  656.389605]  ? ___sys_recvmsg+0xa2/0xf0\n[  656.389889]  ? handle_mm_fault+0x1671/0x21d0\n[  656.390201]  __sys_sendmsg+0x6d/0xe0\n[  656.390464]  __x64_sys_sendmsg+0x23/0x30\n[  656.390751]  do_syscall_64+0x45/0x70\n[  656.391017]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nTo fix it, just add if (nbd->recv_workq) to nbd_disconnect_and_put()."
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1c4962df938891af9ab4775f5224ef8601764107",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/54b78ba7e96e5fe1edb8054e375d31a6c0dc60dc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/79ebe9110fa458d58f1fceb078e2068d7ad37390",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b31d237796fd618379ec8e0f4de3370b5e4aeee7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cde4b55cfb24522dcbba80bbdb0c082303e76c43",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}