{"id":"DEBIAN-CVE-2022-50648","details":"In the Linux kernel, the following vulnerability has been resolved:  ftrace: Fix recursive locking direct_mutex in ftrace_modify_direct_caller  Naveen reported recursive locking of direct_mutex with sample ftrace-direct-modify.ko:  [   74.762406] WARNING: possible recursive locking detected [   74.762887] 6.0.0-rc6+ #33 Not tainted [   74.763216] -------------------------------------------- [   74.763672] event-sample-fn/1084 is trying to acquire lock: [   74.764152] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \\     register_ftrace_function+0x1f/0x180 [   74.764922] [   74.764922] but task is already holding lock: [   74.765421] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \\     modify_ftrace_direct+0x34/0x1f0 [   74.766142] [   74.766142] other info that might help us debug this: [   74.766701]  Possible unsafe locking scenario: [   74.766701] [   74.767216]        CPU0 [   74.767437]        ---- [   74.767656]   lock(direct_mutex); [   74.767952]   lock(direct_mutex); [   74.768245] [   74.768245]  *** DEADLOCK *** [   74.768245] [   74.768750]  May be due to missing lock nesting notation [   74.768750] [   74.769332] 1 lock held by event-sample-fn/1084: [   74.769731]  #0: ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \\     modify_ftrace_direct+0x34/0x1f0 [   74.770496] [   74.770496] stack backtrace: [   74.770884] CPU: 4 PID: 1084 Comm: event-sample-fn Not tainted ... [   74.771498] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [   74.772474] Call Trace: [   74.772696]  \u003cTASK\u003e [   74.772896]  dump_stack_lvl+0x44/0x5b [   74.773223]  __lock_acquire.cold.74+0xac/0x2b7 [   74.773616]  lock_acquire+0xd2/0x310 [   74.773936]  ? register_ftrace_function+0x1f/0x180 [   74.774357]  ? lock_is_held_type+0xd8/0x130 [   74.774744]  ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [   74.775213]  __mutex_lock+0x99/0x1010 [   74.775536]  ? register_ftrace_function+0x1f/0x180 [   74.775954]  ? slab_free_freelist_hook.isra.43+0x115/0x160 [   74.776424]  ? ftrace_set_hash+0x195/0x220 [   74.776779]  ? register_ftrace_function+0x1f/0x180 [   74.777194]  ? kfree+0x3e1/0x440 [   74.777482]  ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [   74.777941]  ? __schedule+0xb40/0xb40 [   74.778258]  ? register_ftrace_function+0x1f/0x180 [   74.778672]  ? my_tramp1+0xf/0xf [ftrace_direct_modify] [   74.779128]  register_ftrace_function+0x1f/0x180 [   74.779527]  ? ftrace_set_filter_ip+0x33/0x70 [   74.779910]  ? __schedule+0xb40/0xb40 [   74.780231]  ? my_tramp1+0xf/0xf [ftrace_direct_modify] [   74.780678]  ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [   74.781147]  ftrace_modify_direct_caller+0x5b/0x90 [   74.781563]  ? 0xffffffffa0201000 [   74.781859]  ? my_tramp1+0xf/0xf [ftrace_direct_modify] [   74.782309]  modify_ftrace_direct+0x1b2/0x1f0 [   74.782690]  ? __schedule+0xb40/0xb40 [   74.783014]  ? simple_thread+0x2a/0xb0 [ftrace_direct_modify] [   74.783508]  ? __schedule+0xb40/0xb40 [   74.783832]  ? my_tramp2+0x11/0x11 [ftrace_direct_modify] [   74.784294]  simple_thread+0x76/0xb0 [ftrace_direct_modify] [   74.784766]  kthread+0xf5/0x120 [   74.785052]  ? kthread_complete_and_exit+0x20/0x20 [   74.785464]  ret_from_fork+0x22/0x30 [   74.785781]  \u003c/TASK\u003e  Fix this by using register_ftrace_function_nolock in ftrace_modify_direct_caller.","modified":"2026-09-01T20:05:00.574915143Z","published":"2025-12-09T01:16:47.490Z","upstream":["CVE-2022-50648"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-50648"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50648.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50648.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50648.json"}}],"schema_version":"1.9.0"}