{"cve":"CVE-2025-71080","nvd":{"published":"2026-01-13T16:16:07.550","modified":"2026-07-30T06:24:49.263","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT\n\nOn PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the\ncurrent task can be preempted. Another task running on the same CPU\nmay then execute rt6_make_pcpu_route() and successfully install a\npcpu_rt entry. When the first task resumes execution, its cmpxchg()\nin rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer\nNULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding\nmdelay() after rt6_get_pcpu_route().\n\nUsing preempt_disable/enable is not appropriate here because\nip6_rt_pcpu_alloc() may sleep.\n\nFix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:\nfree our allocation and return the existing pcpu_rt installed by\nanother task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT\nkernels where such races should not occur.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-617"],"references":["https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d","https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66","https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:19:41.481987139+00:00"},"epss":{"cve":"CVE-2025-71080","score":0.00304,"percentile":0.23258,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}