CVE-2022-49291 Information

Description

In the Linux kernel the following vulnerability has been resolved:

ALSA: pcm: Fix races among concurrent hw_params and hw_free calls

Currently we have neither proper check nor protection against the concurrent calls of PCM hw_params and hw_free ioctls which may result in a UAF. Since the existing PCM stream lock can’t be used for protecting the whole ioctl operations we need a new mutex to protect those racy calls.

This patch introduced a new mutex runtime->buffer_mutex and applies it to both hw_params and hw_free ioctl code paths. Along with it the both functions are slightly modified (the mmap_count check is moved into the state-check block) for code simplicity.

Reference

https://git.kernel.org/stable/c/0090c13cbbdffd7da079ac56f80373a9a1be0bf8 https://git.kernel.org/stable/c/0f6947f5f5208f6ebd4d76a82a4757e2839a23f8 https://git.kernel.org/stable/c/1bbf82d9f961414d6c76a08f7f843ea068e0ab7b https://git.kernel.org/stable/c/33061d0fba51d2bf70a2ef9645f703c33fe8e438 https://git.kernel.org/stable/c/92ee3c60ec9fe64404dc035e7c41277d74aa26cb https://git.kernel.org/stable/c/9cb6c40a6ebe4a0cfc9d6a181958211682cffea9 https://git.kernel.org/stable/c/a42aa926843acca96c0dfbde2e835b8137f2f092 https://git.kernel.org/stable/c/fbeb492694ce0441053de57699e1e2b7bc148a69