cbcvebase.
CVE-2025-71097
published 2026-01-13

CVE-2025-71097: In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix reference count leak when using error routes with nexthop objects When a nexthop…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.11%
1.7th percentile
In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix reference count leak when using error routes with nexthop objects When a nexthop object is deleted, it is marked as dead and then fib_table_flush() is called to flush all the routes that are using the dead nexthop. The current logic in fib_table_flush() is to only flush error routes (e.g., blackhole) when it is called as part of network namespace dismantle (i.e., with flush_all=true). Therefore, error routes are not flushed when their nexthop object is deleted: # ip link add name dummy1 up type dummy # ip nexthop add id 1 dev dummy1 # ip route add 198.51.100.1/32 nhid 1 # ip route add blackhole 198.51.100.2/32 nhid 1 # ip nexthop del id 1 # ip route show blackhole 198.51.100.2 nhid 1 dev dummy1 As such, they keep holding a reference on the nexthop object which in turn holds a reference on the nexthop device, resulting in a reference count leak: # ip link del dev dummy1 [ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2 Fix by flushing error routes when their nexthop is marked as dead. IPv6 does not suffer from this problem.

Affected

66 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.162-1 (bookworm)linux 6.1.162-1 (bookworm)
debianlinux-6.1< linux 6.1.162-1 (bookworm)linux 6.1.162-1 (bookworm)
linuxlinux
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < 5de7ad7e18356e39e8fbf7edd185a5faaf4f385a5de7ad7e18356e39e8fbf7edd185a5faaf4f385a
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < 33ff5c207c873215e54e6176624ed57423cb7dea33ff5c207c873215e54e6176624ed57423cb7dea
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < 30386e090c49e803c0616a7147e43409c32a2b0e30386e090c49e803c0616a7147e43409c32a2b0e
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < 5979338c83012110ccd45cae6517591770bfe5365979338c83012110ccd45cae6517591770bfe536
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < ee4183501ea556dca31f5ffd8690aa9fd25b609fee4183501ea556dca31f5ffd8690aa9fd25b609f
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < e3fc381320d04e4a74311e576a86cac49a16fc43e3fc381320d04e4a74311e576a86cac49a16fc43
linuxlinux>= 493ced1ac47c48bb86d9d4e8e87df8592be85a0e < ac782f4e3bfcde145b8a7f8af31d9422d94d172aac782f4e3bfcde145b8a7f8af31d9422d94d172a
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.249-15.10.249-1
linuxlinux_kernel>= 0 < 6.1.162-16.1.162-1
linuxlinux_kernel>= 0 < 6.12.69-16.12.69-1
linuxlinux_kernel>= 0 < 6.18.5-16.18.5-1
linuxlinux_kernel>= 0 < 5.15.0-173.1835.15.0-173.183
linuxlinux_kernel>= 5.11 < 5.15.1985.15.198

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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