CVEvulnerability
CVE-2026-97919
- Status
- Received
- Published
- 2026-09-25
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
tracing: Take the reference before publishing the named histogram trigger
event_hist_trigger_named_init() puts the trigger on the global
named_triggers list and only then takes the reference on the trigger it
shares its histogram with:
data->ref++;
save_named_trigger(data->named_data->name, data);
ret = event_hist_trigger_init(data->named_data);
if (ret < 0) {
kfree(data->cmd_ops);
data->cmd_ops = &trigger_hist_cmd;
}
return ret;
event_hist_trigger_init() fails when alloc_hist_pad() cannot allocate, and
nothing takes the trigger back off the list on the way out.
event_hist_trigger_parse() frees it, and the next lookup by name reads the
freed object:
BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0
Read of size 8 at addr ffff888009346860 by task init/1
find_named_trigger+0xac/0xc0
hist_register_trigger+0xc1/0xa00
event_hist_trigger_parse+0x3146/0x6af0
event_trigger_write+0xce/0x160
Freed by task 67:
kfree+0x154/0x420
trigger_kthread_fn+0xfd/0x160
Do the reference first and publish once it has succeeded, so that nothing
which can fail runs after the trigger becomes findable.
References
- https://git.kernel.org/stable/c/0fe23b8eaba0d3372c66b7b31204408da0715edc git.kernel.org
- https://git.kernel.org/stable/c/2ffaade3611bd9501bc0b9d5d19fc75bfee7a16b git.kernel.org
- https://git.kernel.org/stable/c/91c15cdda6033e2439f5975b938754152f3d6e38 git.kernel.org
- https://git.kernel.org/stable/c/b6fb2f5370a9a6aec325ab2db1ca3d1a881499b8 git.kernel.org
- https://git.kernel.org/stable/c/e5c5dad169fb569161d3eed6c3f6a59e65db1830 git.kernel.org