{"cve":"CVE-2022-48983","nvd":{"published":"2024-10-21T20:15:10.283","modified":"2026-06-17T05:16:46.507","status":"Analyzed","description":"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]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/998b30c3948e4d0b1097e639918c5cff332acac5","https://git.kernel.org/stable/c/d91edca1943453aaaba4f380f6f364346222e5cf","https://git.kernel.org/stable/c/f895511de9d27fff71dad2c234ad53b4afd2b06c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2022-48983","score":0.00262,"percentile":0.18016,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}