Vulnerability Details CVE-2026-31481
In the Linux kernel, the following vulnerability has been resolved:
tracing: Drain deferred trigger frees if kthread creation fails
Boot-time trigger registration can fail before the trigger-data cleanup
kthread exists. Deferring those frees until late init is fine, but the
post-boot fallback must still drain the deferred list if kthread
creation never succeeds.
Otherwise, boot-deferred nodes can accumulate on
trigger_data_free_list, later frees fall back to synchronously freeing
only the current object, and the older queued entries are leaked
forever.
To trigger this, add the following to the kernel command line:
trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon
The second traceon trigger will fail and be freed. This triggers a NULL
pointer dereference and crashes the kernel.
Keep the deferred boot-time behavior, but when kthread creation fails,
drain the whole queued list synchronously. Do the same in the late-init
drain path so queued entries are not stranded there either.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 2.9%
CVSS Severity
CVSS v3 Score 5.5
References
Products affected by CVE-2026-31481
-
cpe:2.3:o:linux:linux_kernel:6.19
-
cpe:2.3:o:linux:linux_kernel:6.19.1
-
cpe:2.3:o:linux:linux_kernel:6.19.10
-
cpe:2.3:o:linux:linux_kernel:6.19.3
-
cpe:2.3:o:linux:linux_kernel:6.19.4
-
cpe:2.3:o:linux:linux_kernel:6.19.6
-
cpe:2.3:o:linux:linux_kernel:6.19.7
-
cpe:2.3:o:linux:linux_kernel:6.19.8
-
cpe:2.3:o:linux:linux_kernel:6.19.9
-
cpe:2.3:o:linux:linux_kernel:7.0