CVE Catalog

CVE-2026-43374

High
Published: Translated: NVD NIST

Summary

A vulnerability has been identified in the Linux kernel related to use-after-free in the remove_nh_grp_entry() function. The issue occurs when removing a nexthop from a group, potentially leading to dereferencing freed percpu memory stats.

Risk Assessment

Organizations may be exposed to attacks that exploit this vulnerability to access freed memory, potentially leading to unpredictable system behavior or crashes.

Recommendation

It is recommended to update the Linux kernel to the latest version where this vulnerability has been fixed to minimize the risk associated with use-after-free.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS