CVE-2025-21899

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix bad hist from corrupting named_triggers list

The following commands causes a crash:

~# cd /sys/kernel/tracing/events/rcu/rcu_callback

~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger

bash: echo: write error: Invalid argument

~# echo 'hist:name=bad:keys=common_pid' > trigger

Because the following occurs:

event_trigger_write() {

trigger_process_regex() {

event_hist_trigger_parse() {

data = event_trigger_alloc(..);

event_trigger_register(.., data) {

cmd_ops->reg(.., data, ..) [hist_register_trigger()] {

data->ops->init() [event_hist_trigger_init()] {

save_named_trigger(name, data) {

list_add(&data->named_list, &named_triggers);

}

}

}

}

ret = create_actions(); (return -EINVAL)

if (ret)

goto out_unreg;

[..]

ret = hist_trigger_enable(data, ...) {

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References