{"cve":"CVE-2025-71097","nvd":{"published":"2026-01-13T16:16:09.583","modified":"2026-10-19T19:17:11.570","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: Fix reference count leak when using error routes with nexthop objects\n\nWhen a nexthop object is deleted, it is marked as dead and then\nfib_table_flush() is called to flush all the routes that are using the\ndead nexthop.\n\nThe current logic in fib_table_flush() is to only flush error routes\n(e.g., blackhole) when it is called as part of network namespace\ndismantle (i.e., with flush_all=true). Therefore, error routes are not\nflushed when their nexthop object is deleted:\n\n # ip link add name dummy1 up type dummy\n # ip nexthop add id 1 dev dummy1\n # ip route add 198.51.100.1/32 nhid 1\n # ip route add blackhole 198.51.100.2/32 nhid 1\n # ip nexthop del id 1\n # ip route show\n blackhole 198.51.100.2 nhid 1 dev dummy1\n\nAs such, they keep holding a reference on the nexthop object which in\nturn holds a reference on the nexthop device, resulting in a reference\ncount leak:\n\n # ip link del dev dummy1\n [   70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2\n\nFix by flushing error routes when their nexthop is marked as dead.\n\nIPv6 does not suffer from this problem.","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-401"],"references":["https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e","https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea","https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536","https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a","https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-71097","score":0.0014,"percentile":0.03351,"date":"2026-10-25"},"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."]}