Executive brief
A vulnerability was identified in the Linux kernel's networking subsystem that could lead to a system crash. The issue occurs when the system processes specific types of fragmented network traffic using high-performance data paths (XDP). An attacker could potentially exploit this to cause a denial-of-service, impacting the availability of the affected server.
Technical details
A vulnerability in the Linux kernel's BPF devmap component arises from the improper handling of fragmented frames during broadcast redirects. When cloning a native XDP frame, the process only copies linear data, leaving the 'XDP_FLAGS_HAS_FRAGS' flag set without valid metadata for the fragments stored in the tailroom. During the subsequent frame return/free path, the kernel may interpret uninitialized tail data as 'skb_shared_info', resulting in an out-of-bounds access. This affects both native XDP (dev_map_enqueue_clone) and generic XDP (dev_map_redirect_clone) paths. The fix involves rejecting fragmented frames in these specific cloning paths to prevent memory corruption.
Affected products
- Linux Linux Kernel 5.14 to 5.15.212, 6.1.101, 6.6.42, 6.9.11, 6.10.1
Timeline
- 2026-07-25: disclosed
- 2026-07-25: advisory
- 2026-07-24: patched
References
- https://git.kernel.org/stable/c/07a4c11ee8ef4abcb39d922e9e410ae269671cdf
- https://git.kernel.org/stable/c/47baddc856ae7e93a565dd9deeb797999b179466
- https://git.kernel.org/stable/c/51d07c12ca411e692c424ecdabf077f1e61a61be
- https://git.kernel.org/stable/c/a9bb2d9c798cb62a4050a991c27b752770c33afe
- https://git.kernel.org/stable/c/aa496720618f1a6054f1c870bf10b4f6c99bf656
- https://git.kernel.org/stable/c/bccbab36ff228e0825eb85d9b0f9b8434cd0a399
- https://git.kernel.org/stable/c/c5b4f5efcb55c1af3fe44ff712d31b7fb098a831