CVE-2026-43374 (GCVE-0-2026-43374)
Vulnerability from cvelistv5
Published
2026-05-08 14:21
Modified
2026-10-19 19:16
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
Impacted products
Vendor Product Version
Linux Linux Version: f4676ea74b8549cd88dbfe2a592ce4530039e61f
Version: f4676ea74b8549cd88dbfe2a592ce4530039e61f
Version: f4676ea74b8549cd88dbfe2a592ce4530039e61f
Version: f4676ea74b8549cd88dbfe2a592ce4530039e61f
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