CVE-2025-71080

MEDIUM EPSS 2.1%
Published Jan 13, 20265mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Jan 13, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-617

Affected Products 11

VendorProductVersionRange
linuxlinux_kernel*≥6.12.1  –  <6.12.64
linuxlinux_kernel*≥6.13  –  <6.18.4
linuxlinux_kernel6.12any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any

References 3

  • git.kernel.org https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651
    Patch