Executive brief
A vulnerability in the Linux kernel's networking subsystem could allow a local attacker to cause a system crash or potentially gain unauthorized access to data. The issue occurs when the system handles specific types of network packets (AF_RXRPC) that share memory fragments with other processes. By manipulating these shared fragments during decryption, an attacker can trigger memory corruption.
Technical details
A vulnerability exists in the Linux kernel's AF_RXRPC implementation within net/rxrpc/call_event.c and net/rxrpc/conn_event.c. The DATA-packet and RESPONSE handlers only unshared socket buffers (skb) when skb_cloned() was true. However, buffers carrying externally-owned paged fragments (e.g., via splice() or chained frag lists) could bypass this check and proceed to in-place decryption. This allows the decryption process to bind shared frag pages directly into the AEAD/skcipher scatter-gather list, leading to a CWE-787 out-of-bounds write. The fix extends the unsharing logic to include cases where skb_has_frag_list() or skb_has_shared_frag() is true.
Affected products
- Linux Linux kernel 5.3 to 6.18.29, 6.19 to 7.0.6
Timeline
- 2026-05-08: other: Patch authored
- 2026-05-11: advisory: NVD publication date
- 2026-05-11: patched: Mainline patch committed
References
- https://git.kernel.org/stable/c/3711382a77342a9a1c3d2e7330dcfc7ea927f568
- https://git.kernel.org/stable/c/3eae0f4f9f7206a4801efa5e0235c25bbd5a412c
- https://git.kernel.org/stable/c/7c504ffab3efce8f7e4f463b314ae31030bdf18b
- https://git.kernel.org/stable/c/aa54b1d27fe0c2b78e664a34fd0fdf7cd1960d71
- https://git.kernel.org/stable/c/d45179f8795222ce858770dc619abe51f9d24411
- https://github.com/V4bel/dirtyfrag