{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.9-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  tracing: Fix NULL pointer dereference in module event cache removal  A module-only event filter such as \":mod:foo\" is cached with a NULL event_mod-\u003ematch when foo has not been loaded. If a later write tries to remove a specific match from the same module, remove_cache_mod() passes the NULL cached match to strcmp(), causing a NULL pointer dereference.  The issue can be reproduced from userspace:    echo ':mod:trace_events_kunit_missing' \u003e /sys/kernel/tracing/set_event   echo '!foo_bar:mod:trace_events_kunit_missing' \u003e\u003e /sys/kernel/tracing/set_event  The second write must be a concatenation (\"\u003e\u003e\") to not include O_TRUNC as that would cause ftrace_clear_events() to clear the cached modules lines.  The crash was reproduced on x86_64 QEMU while KUnit workers contended on the event tracing path:    BUG: kernel NULL pointer dereference, address: 0000000000000000   #PF: supervisor read access in kernel mode   RIP: 0010:strcmp+0x10/0x30   Call Trace:    __ftrace_set_clr_event_nolock+0x373/0x4a0    ftrace_set_clr_event+0xf0/0x180    ftrace_event_write+0xdf/0x110    vfs_write+0xf6/0x440    ksys_write+0x68/0xe0    do_syscall_64+0xf9/0x540    entry_SYSCALL_64_after_hwframe+0x77/0x7f  Check event_mod-\u003ematch before comparing it, consistent with the existing NULL checks for the cached system and event fields. The mismatched removal continues to return -EINVAL; a broad cached module filter is removed with \"!:mod:\u003cmodule\u003e\".",
  "id": "DEBIAN-CVE-2026-74633",
  "modified": "2026-09-14T16:47:45.989355149Z",
  "published": "2026-08-22T16:16:36.380Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-74633"
    }
  ],
  "upstream": [
    "CVE-2026-74633"
  ]
}