Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.9, < 6.12.78 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231Patch
- https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924Patch
- https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7Patch
- https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2Patch
FAQ
What is CVE-2026-43374?
CVE-2026-43374 is a vulnerability with a CVSS score of 7.8 (HIGH). 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() publish...
How severe is CVE-2026-43374?
CVE-2026-43374 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-43374?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.