Executive brief
A vulnerability in the Linux kernel's CAAM cryptographic driver could allow sensitive encryption keys to be leaked into system logs. This occurs when specific debug settings are enabled, potentially allowing a local user with access to system logs to view secret keys. This could compromise the confidentiality of encrypted data on the system.
Technical details
An information disclosure vulnerability exists in the Linux kernel's Cryptographic Acceleration and Assurance Module (CAAM) driver. The driver utilized 'print_hex_dump_debug()' in several functions, including 'aead_setkey', 'gcm_setkey', and 'skcipher_setkey', which can output sensitive key material to the kernel log buffer when CONFIG_DYNAMIC_DEBUG is enabled. A local attacker with access to dmesg or system logs could retrieve these keys. The fix replaces these calls with 'print_hex_dump_devel()', which ensures that sensitive material is only dumped in development environments and not in production builds with dynamic debugging enabled.
Affected products
- Linux Linux Kernel 5.3 to 6.10
Timeline
- 2026-04-27: disclosed: Initial patch submitted by Thorsten Blum
- 2026-07-24: patched: Patch committed to stable tree by Greg Kroah-Hartman
- 2026-07-25: advisory: CVE-2026-64316 published
References
- https://git.kernel.org/stable/c/3f57657b6ea23f933371f2c2846322f441773cee
- https://git.kernel.org/stable/c/45c0e3615e5bca5f1fc93357af8d19975c092d4f
- https://git.kernel.org/stable/c/6f7b8e0321f3a8fbbd267d2ac15c671ab59e919e
- https://git.kernel.org/stable/c/8b56ba10105ca34a4b75f7e33d41d96a63815591
- https://git.kernel.org/stable/c/8cf5fb0503129e53052fe29302379cf83891d0fb
- https://git.kernel.org/stable/c/9a53dc0a0ae0486e164e5af3de5f99ab42c5a23e
- https://git.kernel.org/stable/c/cea7302d5d05df74cfb4107897b1ca34163c06b9