The Linux kernel's Btrfs trace event btrfs_sync_file() is executed in an atomic context where sleeping is not allowed. However, it called dput(), which can sleep, leading to a kernel BUG and crash. This occurs because dput() is called after dget_parent(), which is inappropriate in atomic context. The issue can be reproduced by enabling the trace event and running specific filesystem tests. The fix involves removing the calls to dget_parent() and dput(), accessing the parent dentry directly via dentry->d_parent, aligning with the approach used in ext4's equivalent trace event.

This vulnerability can cause a kernel crash (kernel splat) when the affected trace event is enabled and triggered, leading to denial of service. There is no indication of confidentiality or integrity impact. The CVSS score is 5.5 (medium severity), reflecting local attack vector with low privileges required and no user interaction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is applied, avoid enabling the btrfs_sync_file() trace event to prevent triggering the kernel crash.