CVE-2023-0266

A use after free vulnerability exists in the ALSA PCM package in the Linux Kernel. SNDRV_CTL_IOCTL_ELEM_{READ|WRITE}32 is missing locks that can be used in a use-after-free that can result in a priviledge escalation to gain ring0 access from the system user. We recommend upgrading past commit 56b88b50565cd8b946a2d00b0c83927b7ebb055e

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-5.10/alsa-pcm-move-rwsem-lock-inside-snd_ctl_elem_read-to-prevent-uaf.patch?id=72783cf35e6c55bca84c4bb7b776c58152856fd4
• https://github.com/torvalds/linux/commit/56b88b50565cd8b946a2d00b0c83927b7ebb055e
• https://github.com/torvalds/linux/commit/becf9e5d553c2389d857a3c178ce80fdb34a02e1
• https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-5.10/alsa-pcm-move-rwsem-lock-inside-snd_ctl_elem_read-to-prevent-uaf.patch?id=72783cf35e6c55bca84c4bb7b776c58152856fd4
• https://github.com/torvalds/linux/commit/56b88b50565cd8b946a2d00b0c83927b7ebb055e
• https://github.com/torvalds/linux/commit/becf9e5d553c2389d857a3c178ce80fdb34a02e1
• https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html