{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.9-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  kprobes: Fix permanent hang when flushing the kprobe optimizer  Writing 0 to /proc/sys/debug/kprobes-optimization while a kprobe is jump-optimized never returns. The writer sleeps in D state forever with kprobe_sysctl_mutex held, so any later read or write of that sysctl hangs as well. For example, with vfs_read+9 as an optimizable address in this build:    # cd /sys/kernel/tracing   # echo 'p:myprobe vfs_read+9' \u003e\u003e kprobe_events   # echo 1 \u003e events/kprobes/myprobe/enable   # # wait until /sys/kernel/debug/kprobes/list shows [OPTIMIZED]   # echo 0 \u003e /proc/sys/debug/kprobes-optimization    INFO: task sh:246 blocked for more than 10 seconds.   Call Trace:    \u003cTASK\u003e    __schedule+0x1176/0x4f70    schedule+0xdc/0x2c0    schedule_timeout+0x17b/0x260    wait_for_completion+0x173/0x3c0    wait_for_kprobe_optimizer_locked+0xbc/0x130    proc_kprobes_optimization_handler+0x156/0x1b0    proc_sys_call_handler+0x324/0x490    vfs_write+0x52d/0xfe0    ksys_write+0xff/0x200    do_syscall_64+0x106/0x630    entry_SYSCALL_64_after_hwframe+0x77/0x7f    \u003c/TASK\u003e   ...   INFO: task cat:265 is blocked on a mutex likely owned by task sh:246.  wait_for_kprobe_optimizer_locked() reinitializes optimizer_completion, asks the optimizer thread to flush and sleeps in wait_for_completion(). The thread drains the (un)optimizing lists, but calls complete() only if completion_done() is true, i.e. if the completion is already done, which never happens while someone waits. disarm_all_kprobes() and kprobe_trace_self_tests_init() wait the same way.  Calling complete() unconditionally would not be enough: the waiter drops kprobe_mutex while it sleeps, and nothing else serializes the sysctl handler against the debugfs \"enabled\" file. A second flusher that still finds the lists non-empty, e.g. because a disabled probe is queued for unoptimizing, reinitializes the completion under the first:    sysctl write                      debugfs \"enabled\" write   unoptimize_all_kprobes()     wait_for_kprobe_optimizer_locked()       init_completion(c)       mutex_unlock(\u0026kprobe_mutex)       wait_for_completion(c)                                     disarm_all_kprobes()                                       wait_for_kprobe_optimizer_locked()                                         init_completion(c)                                           // c-\u003ewait is reset, the first                                           // waiter is off the queue                                         mutex_unlock(\u0026kprobe_mutex)                                         wait_for_completion(c)   kprobe_optimizer()     complete(c)       // wakes the debugfs writer only  where c is \u0026optimizer_completion. Lining up the two writes during an optimizer pass loses the sysctl writer this way.  Replace the completion with a counter of optimizer passes, bumped at the end of each pass and signalled with wake_up_var_locked(), both under kprobe_mutex. A flusher samples the count and waits with wait_var_event_mutex(), which drops kprobe_mutex only while sleeping, so a new count means a whole pass ran in the meantime. Nothing is reinitialized, so several flushers can sleep in the wait at once.",
  "id": "DEBIAN-CVE-2026-98530",
  "modified": "2026-10-19T04:47:30.408310096Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98530"
    }
  ],
  "upstream": [
    "CVE-2026-98530"
  ]
}