Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_pedit: fix TOCTOU heap OOB write in tc offload There is a TOCTOU race condition in flower lockless approach between sizing a flow_rule buffer and filling it. zdi-disclosures@trendmicro.com reports: The cls_flower classifier operates with TCF_PROTO_OPS_DOIT_UNLOCKED (fl_change runs without RTNL), while RTM_NEWACTION holds RTNL, so the independent locking domains make the race reachable in practice. KASAN confirms: BUG: KASAN: slab-out-of-bounds in tcf_pedit_offload_act_setup+0x81b/0x930 Write of size 4 at addr ffff888001f27520 by task poc-toctou/312 The buggy address is located 0 bytes to the right of allocated 288-byte region [ffff888001f27400, ffff888001f27520) (cache kmalloc-512) Note: The result is a heap OOB write attacker-controlled content into the adjacent slab object (requires CAP_NET_ADMIN). The fix introduces reading tcfp_nkeys under act->tcfa_lock in all places using a new tcf_pedit_nkeys_locked() which replaces the old tcf_pedit_nkeys(). Additionally we close the remaining TOCTOU window between the sizing read and the fill reads by more careful accounting. Rather than silently truncating the key count, which leads to incorrect action semantics offloaded to hardware and secondary OOB writes if the remaining capacity is zero or consumed by prior actions, we enforce remaining capacity checks and return -ENOSPC if the required space exceeds the remaining capacity.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 71d0ed7079dffbc5cd0941d77d9b84e04109c9bb before 0d8532a5e972a5351cf4ee4a435e0d65cbba8f23; affected 71d0ed7079dffbc5cd0941d77d9b84e04109c9bb before 27488e1a7f19757e6146edca9458ed4ffc545557; affected 71d0ed7079dffbc5cd0941d77d9b84e04109c9bb before 6f9b23eb92a894ae1118893996943990ee0b860e; affected 71d0ed7079dffbc5cd0941d77d9b84e04109c9bb before 8e49cd891bda447c68122d672510a604a8bb6b24; affected 71d0ed7079dffbc5cd0941d77d9b84e04109c9bb before 8b519cbcabe836a441369fbec1a8a6518a709251 |
| Linux / Linux | affected 4.11; unaffected 0 before 4.11; unaffected 6.6.145 through 6.6.*; unaffected 6.12.97 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/0d8532a5e972a5351cf4ee4a435e0d65cbba8f23
- https://git.kernel.org/stable/c/27488e1a7f19757e6146edca9458ed4ffc545557
- https://git.kernel.org/stable/c/6f9b23eb92a894ae1118893996943990ee0b860e
- https://git.kernel.org/stable/c/8e49cd891bda447c68122d672510a604a8bb6b24
- https://git.kernel.org/stable/c/8b519cbcabe836a441369fbec1a8a6518a709251
ADP enrichment
No English description supplied.
No references supplied.