In the Linux kernel, the following vulnerability has been resolved:
btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()
If overlay is used on top of btrfs, dentry->d_sb translates to overlay's super block and fsid assignment will lead to a crash.
Use file_inode(file)->i_sb to always get btrfs_sb.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:HI:NA:H9.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H