{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: Fix a null-ptr-deref in io_tctx_exit_cb()\n\nSyzkaller reports a NULL deref bug as follows:\n\n BUG: KASAN: null-ptr-deref in io_tctx_exit_cb+0x53/0xd3\n Read of size 4 at addr 0000000000000138 by task file1/1955\n\n CPU: 1 PID: 1955 Comm: file1 Not tainted 6.1.0-rc7-00103-gef4d3ea40565 #75\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0xcd/0x134\n  ? io_tctx_exit_cb+0x53/0xd3\n  kasan_report+0xbb/0x1f0\n  ? io_tctx_exit_cb+0x53/0xd3\n  kasan_check_range+0x140/0x190\n  io_tctx_exit_cb+0x53/0xd3\n  task_work_run+0x164/0x250\n  ? task_work_cancel+0x30/0x30\n  get_signal+0x1c3/0x2440\n  ? lock_downgrade+0x6e0/0x6e0\n  ? lock_downgrade+0x6e0/0x6e0\n  ? exit_signals+0x8b0/0x8b0\n  ? do_raw_read_unlock+0x3b/0x70\n  ? do_raw_spin_unlock+0x50/0x230\n  arch_do_signal_or_restart+0x82/0x2470\n  ? kmem_cache_free+0x260/0x4b0\n  ? putname+0xfe/0x140\n  ? get_sigframe_size+0x10/0x10\n  ? do_execveat_common.isra.0+0x226/0x710\n  ? lockdep_hardirqs_on+0x79/0x100\n  ? putname+0xfe/0x140\n  ? do_execveat_common.isra.0+0x238/0x710\n  exit_to_user_mode_prepare+0x15f/0x250\n  syscall_exit_to_user_mode+0x19/0x50\n  do_syscall_64+0x42/0xb0\n  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n RIP: 0023:0x0\n Code: Unable to access opcode bytes at 0xffffffffffffffd6.\n RSP: 002b:00000000fffb7790 EFLAGS: 00000200 ORIG_RAX: 000000000000000b\n RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000\n RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000\n R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n  </TASK>\n Kernel panic - not syncing: panic_on_warn set ...\n\nThis happens because the adding of task_work from io_ring_exit_work()\nisn't synchronized with canceling all work items from eg exec. The\nexecution of the two are ordered in that they are both run by the task\nitself, but if io_tctx_exit_cb() is queued while we're canceling all\nwork items off exec AND gets executed when the task exits to userspace\nrather than in the main loop in io_uring_cancel_generic(), then we can\nfind current->io_uring == NULL and hit the above crash.\n\nIt's safe to add this NULL check here, because the execution of the two\npaths are done by the task itself.\n\n[axboe: add code comment and also put an explanation in the commit msg]"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "io_uring/io_uring.c"
               ],
               "versions": [
                  {
                     "version": "d56d938b4bef",
                     "lessThan": "f895511de9d2",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d56d938b4bef",
                     "lessThan": "d91edca19434",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d56d938b4bef",
                     "lessThan": "998b30c3948e",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "io_uring/io_uring.c"
               ],
               "versions": [
                  {
                     "version": "5.12",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.12",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.83",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.0.13",
                     "lessThanOrEqual": "6.0.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/f895511de9d27fff71dad2c234ad53b4afd2b06c"
            },
            {
               "url": "https://git.kernel.org/stable/c/d91edca1943453aaaba4f380f6f364346222e5cf"
            },
            {
               "url": "https://git.kernel.org/stable/c/998b30c3948e4d0b1097e639918c5cff332acac5"
            }
         ],
         "title": "io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2022-48983",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}