CVE-2026-74739 (GCVE-0-2026-74739)
Vulnerability from cvelistv5
Published
2026-08-26 14:36
Modified
2026-10-16 19:16
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: skip hash tables in u32_bind_class() u32_walk() enumerates both struct tc_u_hnode and struct tc_u_knode through the walker callback. u32_bind_class() unconditionally casts the passed fh to tc_u_knode and accesses &n->res, so when fh is actually a tc_u_hnode, which has no tcf_result member, this results in a slab-out-of-bounds read of res->classid in tc_cls_bind_class(). The issue can be reproduced with the following commands: tc qdisc add dev lo root handle 1: hfsc tc class add dev lo parent 1: classid 1:1 hfsc sc rate 1000kbit tc filter add dev lo parent 1:1 protocol ip prio 1 u32 match u32 0 0 flowid 1:1 tc class add dev lo parent 1: classid 1:2 hfsc sc rate 2000kbit Fix this by skipping hash tables via the TC_U32_KEY(handle) check.
References
Impacted products
Vendor Product Version
Linux Linux Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
Version: 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1
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