Executive brief
A vulnerability was identified in the Linux kernel's cryptographic subsystem that could lead to system instability. The issue occurs when the system processes specific encryption requests, causing it to write data beyond the intended memory boundaries. This could potentially be used by a local attacker to crash the system or corrupt memory.
Technical details
A buffer overflow exists in the Linux kernel's CCP (Crypto Coprocessor) driver within the `ccp_aes_complete()` function. When processing `rfc3686-ctr-aes-ccp` requests via AF_ALG, the driver incorrectly assumes a fixed IV size of `AES_BLOCK_SIZE` (16 bytes) when restoring the IV to the caller's buffer. However, RFC3686 symmetric ciphers utilize an 8-byte IV, leading to a heap-based buffer overflow during the `memcpy` operation. An attacker with local access could exploit this to corrupt adjacent memory or cause a kernel panic. The issue has been resolved by using `crypto_skcipher_ivsize()` to ensure only the correct number of bytes are copied.
Affected products
- Linux Linux 3.14 to 6.14.y
Timeline
- 2026-04-16: patched: Initial fix in mainline kernel
- 2026-06-24: disclosed: CVE published
References
- https://git.kernel.org/stable/c/227c1e1d9e2aa4cfc65ba446d5690da1f546cda4
- https://git.kernel.org/stable/c/798d409a8949f3f495f238549b86de2886b129bd
- https://git.kernel.org/stable/c/939061b2d0f7f15114e34b4ce878ef50ff4089c3
- https://git.kernel.org/stable/c/a7a1f3cdd64d8a165d9b8c9e9ad7fb46ac19dfc4
- https://git.kernel.org/stable/c/bb01d8f1f385bc9034ca114d3508c7fdea24fc9a
- https://git.kernel.org/stable/c/df9784bb5b637ac80f4a2768a58ca9a50bef28a9
- https://git.kernel.org/stable/c/dfb2cf434829819268fe50f41542aad318ad62b2