Executive brief
A vulnerability was identified in the Linux kernel's sound subsystem (ALSA) specifically affecting the Emux synthesizer component. A local user could potentially exploit this flaw to cause a system crash or instability by providing malformed data through specific sound-related system calls. This primarily impacts the availability of the system.
Technical details
A vulnerability in the ALSA emux synthesizer driver (sound/synth/emux/soundfont.c) was caused by insufficient validation of user-supplied data in the patch loading ioctls. Specifically, the load_guspatch() function lacked a check to ensure the specified patch length matched the actual amount of data supplied, and load_data() had inconsistent validation of the main info block. An attacker with local access could exploit this by sending specially crafted ioctl requests to trigger out-of-bounds behaviors or kernel crashes. The fix introduces rigorous length checks and synchronizes validation logic between the load_data() and load_guspatch() functions.
Affected products
- Linux Linux Kernel up to 4.19.317, 4.20 to 5.4.279, 5.5 to 5.10.221, 5.11 to 5.15.162, 5.16 to 6.1.97, 6.2 to 6.6.37, 6.7 to 6.9.8
Timeline
- 2024-07-29: advisory: Initial disclosure of CVE-2024-42097
- 2024-07-05: patched: Fixes committed to various stable kernel branches
References
- https://git.kernel.org/stable/c/40d7def67841343c10f8642a41031fecbb248bab
- https://git.kernel.org/stable/c/79d9a000f0220cdaba1682d2a23c0d0c61d620a3
- https://git.kernel.org/stable/c/7a18293fd8d8519c2f7a03753bc1583b18e3db69
- https://git.kernel.org/stable/c/87039b83fb7bfd7d0e0499aaa8e6c049906b4d14
- https://git.kernel.org/stable/c/89b32ccb12ae67e630c6453d778ec30a592a212f
- https://git.kernel.org/stable/c/d0ff2443fcbb472206d45a5d2a90cc694065804e
- https://git.kernel.org/stable/c/d23982ea9aa438f35a8c8a6305943e98a8db90f6