{"schema_version":"1.9.0","id":"CVE-2022-48983","published":"2024-10-21T20:06:00.376Z","modified":"2026-08-12T03:51:12.022160724Z","related":["SUSE-SU-2024:4315-1","SUSE-SU-2024:4364-1","SUSE-SU-2024:4376-1"],"summary":"io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()","details":"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":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d56d938b4bef3e1421a42023cdcd6e13c1f50831"},{"fixed":"f895511de9d27fff71dad2c234ad53b4afd2b06c"},{"fixed":"d91edca1943453aaaba4f380f6f364346222e5cf"},{"fixed":"998b30c3948e4d0b1097e639918c5cff332acac5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48983.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.12.0"},{"fixed":"5.15.83"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48983.json"}}],"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/998b30c3948e4d0b1097e639918c5cff332acac5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d91edca1943453aaaba4f380f6f364346222e5cf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f895511de9d27fff71dad2c234ad53b4afd2b06c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48983.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-48983"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48983.json"}}