7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Brauner commit b0d1022b9bdb1e98aa7fb3244fdd50a58c61766c upstream. An immutable inode is never written to so write hints are pointless. Refuse the hint on an immutable inode the way setattr(), fallocate() and etxattr() refuse their changes. Fixes: c75b1d9421f8 ("fs: add fcntl() interface for setting/getting write life time hints") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20261002-work-mount-fixes-4-v1-3-dd44b89d44ce@kernel.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman --- fs/fcntl.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -372,6 +372,9 @@ static long fcntl_set_rw_hint(struct fil u64 __user *argp = (u64 __user *)arg; u64 hint; + /* nothing is ever written to it */ + if (IS_IMMUTABLE(inode)) + return -EPERM; if (!inode_owner_or_capable(file_mnt_idmap(file), inode)) return -EPERM;