CVE Catalog

CVE-2025-71080

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.25%

17th percentile - higher than 17% of all known CVEs

Summary

In the Linux kernel, a bug was found in the rt6_get_pcpu_route() function for IPv6 that causes a BUG on PREEMPT_RT kernels. After rt6_get_pcpu_route() returns NULL, the task can be preempted, and another task may install a pcpu_rt entry, causing cmpxchg() to fail and triggering BUG_ON.

Risk Assessment

The bug leads to a kernel panic on PREEMPT_RT systems, potentially causing a denial of service (DoS).

Recommendation

Update the Linux kernel to a version containing the fix that replaces BUG_ON with WARN_ON_ONCE and handles cmpxchg() failure gracefully.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the current task can be preempted. Another task running on the same CPU may then execute rt6_make_pcpu_route() and successfully install a pcpu_rt entry. When the first task resumes execution, its cmpxchg() in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding mdelay() after rt6_get_pcpu_route(). Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep. Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT: free our allocation and return the existing pcpu_rt installed by another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT kernels where such races should not occur.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS