Executive brief
A vulnerability was identified in the Linux kernel's network traffic classifier component. A local attacker could exploit this flaw to cause a system crash or potentially access sensitive information from the system's memory. This affects the stability and data confidentiality of Linux-based servers and workstations.
Technical details
An out-of-bounds (OOB) read vulnerability exists in the Linux kernel's net/sched/cls_u32.c component. The root cause is the use of skb_header_pointer(), which fails to adequately validate negative offset values, allowing u32_classify() to be 'fooled' into reading memory outside of the intended buffer. A local attacker with low privileges can trigger this behavior, leading to a KASAN-detected slab-out-of-bounds error. This can result in a kernel panic (denial of service) or the leakage of sensitive kernel memory. The issue has been resolved by replacing the vulnerable function with skb_header_pointer_careful() across multiple stable kernel branches.
Affected products
- Linux Linux Kernel 2.6.35.1 to 6.6.124, 6.7 to 6.12.70, 6.13 to 6.18.10
Timeline
- 2026-01-28: other: Patch authored by Eric Dumazet
- 2026-01-29: patched: Mainline patch committed
- 2026-02-14: disclosed: CVE published
References
- https://git.kernel.org/stable/c/13336a6239b9d7c6e61483017bb8bdfe3ceb10a5
- https://git.kernel.org/stable/c/29681ed51e737be14d18ecd1c304c57002e4b72c
- https://git.kernel.org/stable/c/8a672f177ebe19c93d795fbe967846084fbc7943
- https://git.kernel.org/stable/c/cabd1a976375780dabab888784e356f574bbaed8
- https://git.kernel.org/stable/c/cfa745830e45ecb75c061aa34330ee0cac941cc7
- https://git.kernel.org/stable/c/e41a23e61259f5526af875c3b86b3d42a9bae0e5