Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix percpu use-after-free in remove_nh_grp_entry When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected f4676ea74b8549cd88dbfe2a592ce4530039e61f before abf4feaee6405f1441929c6ebe7a250f2cd170a7; affected f4676ea74b8549cd88dbfe2a592ce4530039e61f before ab5ebab9664214ba41a7633cb4e72f128204f924; affected f4676ea74b8549cd88dbfe2a592ce4530039e61f before 9e08ad731862b22a87cc55f752e16d66cdc9e231; affected f4676ea74b8549cd88dbfe2a592ce4530039e61f before b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 |
| Linux / Linux | affected 6.9; unaffected 0 before 6.9; unaffected 6.12.78 through 6.12.*; unaffected 6.18.19 through 6.18.*; unaffected 6.19.9 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7
- https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924
- https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231
- https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2
ADP enrichment
No English description supplied.
No references supplied.