https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Mon, 28 Sep 2026 21:30:27 +0000 https://vulnerability.circl.lu/vuln/cve-2025-71080 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT</p> <p>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&#39;s easy to reproduce it by adding mdelay() after rt6_get_pcpu_route().</p> <p>Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep.</p> <p>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.</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT</p> <p>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&#39;s easy to reproduce it by adding mdelay() after rt6_get_pcpu_route().</p> <p>Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep.</p> <p>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.</p> https://vulnerability.circl.lu/vuln/cve-2025-71080