CVE-2025-21728

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

bpf: Send signals asynchronously if !preemptible

BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change irqs_disabled() to !preemptible().

This vulnerability is rated as Moderate because exploiting it requires elevated capabilities, such as CAP_BPF or CAP_SYS_ADMIN, to load and attach the tracing BPF program. While triggering the sleepable function in a non-preemptible execution context can crash the kernel and cause a denial of service, the prerequisite for administrative privileges substantially restricts the risk profile. Default Red Hat Enterprise Linux configurations do not permit unprivileged users to load BPF programs capable of invoking signal-sending functions.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.