CVE-2026-53096
In the Linux kernel, the following vulnerability has been resolved: bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path The DEVMAP_HASH branch in dev_map_redirect_multi() uses hlist_for_each_entry_safe() to iterate hash buckets, but this function runs under RCU protection (called from xdp_do_generic_redirect_map() in softirq context). Concurrent writers (__dev_map_hash_update_elem, dev_map_hash_delete_elem) modify the list using RCU primitives (hlist_add_head_rcu, hlist_del_rcu). hlist_for_each_entry_safe() performs plain pointer dereferences without rcu_dereference(), missing the acquire barrier needed to pair with writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64, POWER), a reader can observe a partially-constructed node. It also defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race detection. Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held() as the lockdep condition, consistent with the rcu_dereference_check() used in the DEVMAP (non-hash) branch of the same functions. Also fix the same incorrect lockdep_is_held(&dtab->index_lock) condition in dev_map_enqueue_multi(), where the lock is not held either.
- CVSS 3.1
- 7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 0% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-476, CWE-362
- Published
- Modified
- Record from
- the NVD, synced
Affected
- linux:linux_kernel
References
- https://git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645
- https://git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392
- https://git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f
- https://git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19
- https://git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc