From: Jan Kara <jack@xxxxxxx> commit 4013d47a5307fdb5c13370b5392498b00fedd274 upstream. When we succeed in enabling some quota type but fail to enable another one with quota feature, we correctly disable all enabled quota types. However we forget to reset i_data_sem lockdep class. When the inode gets freed and reused, it will inherit this lockdep class (i_data_sem is initialized only when a slab is created) and thus eventually lockdep barfs about possible deadlocks. Reported-and-tested-by: syzbot+3b6f9218b1301ddda3e2@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Cc: stable@xxxxxxxxxx Link: https://lore.kernel.org/r/20211007155336.12493-3-jack@xxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/super.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -6427,8 +6427,19 @@ static int ext4_enable_quotas(struct sup "Failed to enable quota tracking " "(type=%d, err=%d). Please run " "e2fsck to fix.", type, err); - for (type--; type >= 0; type--) + for (type--; type >= 0; type--) { + struct inode *inode; + + inode = sb_dqopt(sb)->files[type]; + if (inode) + inode = igrab(inode); dquot_quota_off(sb, type); + if (inode) { + lockdep_set_quota_inode(inode, + I_DATA_SEM_NORMAL); + iput(inode); + } + } return err; }
