Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: netfilter: ebt_nflog: pin the NFLOG backend nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the ULOG logger module reference when an ebt_nflog rule is validated and release it when the rule is destroyed. Request the NFLOG backend for legacy callers when needed, matching xt_NFLOG. This prevents module teardown until all ebt_nflog rules have stopped using the logger.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 3bcce49d617c593c7606083bfdb464a1761fa68d; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 394d7939c6b2b9e6bea0844c89efb5913168d898; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 2cac4294f184c9bc19ff82552c62b80498694c39; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 9d8a94b48b393885e7f876c8ef68ed4da5012078; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 6809379a860b9fccbb5435bf08343f6d081ac68d; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before e2ab7e878bdbe80104c879c31fd2d82a476703b8; affected c83fa19603bdaeef17b815713dbbe3230c8a34ee before 30825970339c107bacaf7f61af90fcdb1f597ca1 |
| Linux / Linux | affected 4.12; unaffected 0 before 4.12; unaffected 5.10.265 through 5.10.*; unaffected 5.15.216 through 5.15.*; unaffected 6.1.183 through 6.1.*; unaffected 6.6.152 through 6.6.*; unaffected 6.12.104 through 6.12.*; unaffected 6.18.45 through 6.18.*; unaffected 7.1.9 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/3bcce49d617c593c7606083bfdb464a1761fa68d
- https://git.kernel.org/stable/c/394d7939c6b2b9e6bea0844c89efb5913168d898
- https://git.kernel.org/stable/c/2cac4294f184c9bc19ff82552c62b80498694c39
- https://git.kernel.org/stable/c/9d8a94b48b393885e7f876c8ef68ed4da5012078
- https://git.kernel.org/stable/c/6809379a860b9fccbb5435bf08343f6d081ac68d
- https://git.kernel.org/stable/c/47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb
- https://git.kernel.org/stable/c/e2ab7e878bdbe80104c879c31fd2d82a476703b8
- https://git.kernel.org/stable/c/30825970339c107bacaf7f61af90fcdb1f597ca1
ADP enrichment
No English description supplied.
No references supplied.