From: Theodore Ts'o tytso@mit.edu
commit aff3bea95388299eec63440389b4545c8041b357 upstream.
Treat i_data_sem for ea_inodes as being in their own lockdep class to avoid lockdep complaints about ext4_setattr's use of inode_lock() on normal inodes potentially causing lock ordering with i_data_sem on ea_inodes in ext4_xattr_inode_write(). However, ea_inodes will be operated on by ext4_setattr(), so this isn't a problem.
Cc: stable@kernel.org Link: https://syzkaller.appspot.com/bug?extid=298c5d8fb4a128bc27b0 Reported-by: syzbot+298c5d8fb4a128bc27b0@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o tytso@mit.edu Link: https://lore.kernel.org/r/20230524034951.779531-5-tytso@mit.edu Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/ext4.h | 2 ++ fs/ext4/xattr.c | 4 ++++ 2 files changed, 6 insertions(+)
--- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1007,11 +1007,13 @@ do { \ * where the second inode has larger inode number * than the first * I_DATA_SEM_QUOTA - Used for quota inodes only + * I_DATA_SEM_EA - Used for ea_inodes only */ enum { I_DATA_SEM_NORMAL = 0, I_DATA_SEM_OTHER, I_DATA_SEM_QUOTA, + I_DATA_SEM_EA };
--- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -123,7 +123,11 @@ ext4_expand_inode_array(struct ext4_xatt #ifdef CONFIG_LOCKDEP void ext4_xattr_inode_set_class(struct inode *ea_inode) { + struct ext4_inode_info *ei = EXT4_I(ea_inode); + lockdep_set_subclass(&ea_inode->i_rwsem, 1); + (void) ei; /* shut up clang warning if !CONFIG_LOCKDEP */ + lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA); } #endif