CVE-2026-43374
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Linux kernel Affected 3 releases
| Version | Status | Fixed in |
|---|---|---|
| 7.0 | Affected | — |
| 6.9 | Affected | — |
| — | Affected | 6.12.78 |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.85-1 |
| sid | Fixed | 6.19.10-1 |
| forky | Fixed | 6.19.10-1 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 0 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| gcp | | |
References
- https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231
- https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924
- https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7
- https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2
- https://www.suse.com/security/cve/CVE-2026-43374.html
- https://security-tracker.debian.org/tracker/CVE-2026-43374
CWEs
CWE-416
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.