Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before 4a3d0fe30b907ff324b1b49756f7e713d67f3645; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before b089aa6e94d7a08e74d076a0fe274842dc9feccc; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before 571a05ea1baaccc0dc1e0d227b2cbc978b96d392; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before d4c4bd231ebad70e6f30db429e9640bf378b2f52; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before 7027e705062482a8cea43a1c13ede3c35653966f; affected e624d4ed4aa8cc3c69d1359b0aaea539203ed266 before 8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19 |
| Linux / Linux | affected 5.14; unaffected 0 before 5.14; unaffected 5.15.209 through 5.15.*; unaffected 6.1.175 through 6.1.*; unaffected 6.6.141 through 6.6.*; unaffected 6.12.91 through 6.12.*; unaffected 6.18.33 through 6.18.*; unaffected 7.0.10 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645
- https://git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc
- https://git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392
- https://git.kernel.org/stable/c/cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a
- https://git.kernel.org/stable/c/d4c4bd231ebad70e6f30db429e9640bf378b2f52
- https://git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f
- https://git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19
ADP enrichment
No English description supplied.
No references supplied.