CVE-2024-26644

Name of the Vulnerable Software and Affected Versions: Linux kernel versions prior to 6.7.0-rc6

Description: The vulnerability is related to the btrfs filesystem in the Linux kernel. When attempting to snapshot a deleted subvolume, the create pending snapshot() function initializes the new root item as a copy of the source root item, including the refs field, which is 0 for a deleted subvolume. This causes the btrfs insert root() function to insert a root with refs == 0, leading to an abort. The issue can be fixed by checking the source root's refs before attempting the snapshot, but after locking subvol sem to avoid racing with deletion.

Recommendations: To resolve the issue, update the Linux kernel to a version that includes the fix for this vulnerability. Specifically, for Linux kernel version 6.7.0-rc6, apply the patch that checks the source root's refs before attempting the snapshot. As a temporary workaround, consider disabling the create pending snapshot() function until a patch is available.