CVE-2024-53150
Description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix out of bounds reads when finding clock sources
The current USB-audio driver code doesn't check bLength of each
descriptor at traversing for clock descriptors. That is, when a
device provides a bogus descriptor with a shorter bLength, the driver
might hit out-of-bounds reads.
For addressing it, this patch adds sanity checks to the validator
functions for the clock descriptor traversal. When the descriptor
length is shorter than expected, it's skipped in the loop.
For the clock source and clock multiplier descriptors, we can just
check bLength against the sizeof() of each descriptor type.
OTOH, the clock selector descriptor of UAC2 and UAC3 has an array
of bNrInPins elements and two more fields at its tail, hence those
have to be checked in addition to the sizeof() check.
Summary dbcve.org
The ALSA USB-audio driver lacks bounds checking when traversing clock descriptors. When a malicious or buggy USB audio device provides descriptors with shorter-than-expected bLength fields, the driver performs out-of-bounds memory reads, potentially exposing kernel memory contents. The fix adds bLength validation against expected descriptor sizes for clock source and multiplier descriptors, plus additional validation for clock selector descriptors (UAC2/UAC3) that include variable-length bNrInPins arrays.
Mitigation
Apply the kernel patch that adds bLength sanity checks before descriptor field access. Until patched, avoid using untrusted USB audio devices with the Linux system.