{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "b355247df104ef6644288884afd2c08b7bf49897"
            },
            {
              "fixed": "152a00440dc6ef62c6e4cf9bd881a7e6bb81fda9"
            },
            {
              "fixed": "ad4e9dd5fec7a322a471ff36fb9c76214e3c6992"
            },
            {
              "fixed": "b69859204d4db3acd86c1c2dadcef0d77b451933"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.14.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74633.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix NULL pointer dereference in module event cache removal\n\nA module-only event filter such as \":mod:foo\" is cached with a NULL\nevent_mod-\u003ematch when foo has not been loaded. If a later write tries to\nremove a specific match from the same module, remove_cache_mod() passes\nthe NULL cached match to strcmp(), causing a NULL pointer dereference.\n\nThe issue can be reproduced from userspace:\n\n  echo ':mod:trace_events_kunit_missing' \u003e /sys/kernel/tracing/set_event\n  echo '!foo_bar:mod:trace_events_kunit_missing' \u003e\u003e /sys/kernel/tracing/set_event\n\nThe second write must be a concatenation (\"\u003e\u003e\") to not include O_TRUNC as\nthat would cause ftrace_clear_events() to clear the cached modules lines.\n\nThe crash was reproduced on x86_64 QEMU while KUnit workers contended on\nthe event tracing path:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  #PF: supervisor read access in kernel mode\n  RIP: 0010:strcmp+0x10/0x30\n  Call Trace:\n   __ftrace_set_clr_event_nolock+0x373/0x4a0\n   ftrace_set_clr_event+0xf0/0x180\n   ftrace_event_write+0xdf/0x110\n   vfs_write+0xf6/0x440\n   ksys_write+0x68/0xe0\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nCheck event_mod-\u003ematch before comparing it, consistent with the existing\nNULL checks for the cached system and event fields. The mismatched removal\ncontinues to return -EINVAL; a broad cached module filter is removed with\n\"!:mod:\u003cmodule\u003e\".",
  "id": "CVE-2026-74633",
  "modified": "2026-08-24T11:36:09.221175517Z",
  "published": "2026-08-22T15:32:13.808Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/152a00440dc6ef62c6e4cf9bd881a7e6bb81fda9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad4e9dd5fec7a322a471ff36fb9c76214e3c6992"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b69859204d4db3acd86c1c2dadcef0d77b451933"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74633.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74633"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "tracing: Fix NULL pointer dereference in module event cache removal"
}