This is a note to let you know that I've just added the patch titled ext4: Fix possible corruption when moving a directory to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-fix-possible-corruption-when-moving-a-directory.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bd21a5512e13f529b9b519d98eaf6535b6a33910 Author: Jan Kara <jack@xxxxxxx> Date: Thu Jan 26 12:22:21 2023 +0100 ext4: Fix possible corruption when moving a directory [ Upstream commit 0813299c586b175d7edb25f56412c54b812d0379 ] When we are renaming a directory to a different directory, we need to update '..' entry in the moved directory. However nothing prevents moved directory from being modified and even converted from the inline format to the normal format. When such race happens the rename code gets confused and we crash. Fix the problem by locking the moved directory. CC: stable@xxxxxxxxxxxxxxx Fixes: 32f7f22c0b52 ("ext4: let ext4_rename handle inline dir") Signed-off-by: Jan Kara <jack@xxxxxxx> Link: https://lore.kernel.org/r/20230126112221.11866-1-jack@xxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index c7791e1957f50..aa689adeeafdf 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3887,9 +3887,16 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir, if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) goto end_rename; } + /* + * We need to protect against old.inode directory getting + * converted from inline directory format into a normal one. + */ + inode_lock_nested(old.inode, I_MUTEX_NONDIR2); retval = ext4_rename_dir_prepare(handle, &old); - if (retval) + if (retval) { + inode_unlock(old.inode); goto end_rename; + } } /* * If we're renaming a file within an inline_data dir and adding or @@ -4014,6 +4021,8 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir, } else { ext4_journal_stop(handle); } + if (old.dir_bh) + inode_unlock(old.inode); release_bh: brelse(old.dir_bh); brelse(old.bh);