In the Linux kernel, the following vulnerability has been resolved: bpf: fs/xattr: don't assume…

Why it is Yellow

• CVSS 7.3 high
• On your watchlist: linux kernel

References

• https://git.kernel.org/stable/c/35d442ed1f86465e49df3119fb898f985186db13
• https://git.kernel.org/stable/c/640d37fbd34d03af727dbc567f48c0203d1de6b4
• https://git.kernel.org/stable/c/7504b677c4370c9e4b153c553ff8831c093b1ff6

Original description

In the Linux kernel, the following vulnerability has been resolved: bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir bpf_lsm_has_d_inode_locked() makes the verifier rewrite bpf_[set|remove]_dentry_xattr() to the _locked variants, which assume that the caller already holds the inode's i_rwsem. The path_unlink and path_rmdir hooks are listed, but security_path_unlink() and security_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the victim inode's i_rwsem, so a sleepable BPF LSM program attached to either hook mutates the victim's xattrs without the lock held. Drop the two path hooks from d_inode_locked_hooks so that the verifier keeps the locking bpf_[set|remove]_dentry_xattr() variants, which take the lock themselves.