Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before 5de7ad7e18356e39e8fbf7edd185a5faaf4f385a; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before 33ff5c207c873215e54e6176624ed57423cb7dea; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before 30386e090c49e803c0616a7147e43409c32a2b0e; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before 5979338c83012110ccd45cae6517591770bfe536; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before ee4183501ea556dca31f5ffd8690aa9fd25b609f; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before e3fc381320d04e4a74311e576a86cac49a16fc43; affected 493ced1ac47c48bb86d9d4e8e87df8592be85a0e before ac782f4e3bfcde145b8a7f8af31d9422d94d172a |
| Linux / Linux | affected 5.3; unaffected 0 before 5.3; unaffected 5.10.248 through 5.10.*; unaffected 5.15.198 through 5.15.*; unaffected 6.1.160 through 6.1.*; unaffected 6.6.120 through 6.6.*; unaffected 6.12.64 through 6.12.*; unaffected 6.18.4 through 6.18.*; unaffected 6.19 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a
- https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea
- https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e
- https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536
- https://git.kernel.org/stable/c/ee4183501ea556dca31f5ffd8690aa9fd25b609f
- https://git.kernel.org/stable/c/e3fc381320d04e4a74311e576a86cac49a16fc43
- https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.