[PATCH AUTOSEL 4.14 35/52] reiserfs: only call unlock_new_inode() if I_NEW

Sasha Levin
2020-10-18T19:36:54Z

From: Eric Biggers <ebiggers@google.com>

[ Upstream commit 8859bf2b1278d064a139e3031451524a49a56bd0 ]

unlock_new_inode() is only meant to be called after a new inode has
already been inserted into the hash table. But reiserfs_new_inode() can
call it even before it has inserted the inode, triggering the WARNING in
unlock_new_inode(). Fix this by only calling unlock_new_inode() if the
inode has the I_NEW flag set, indicating that it's in the table.

This addresses the syzbot report "WARNING in unlock_new_inode"
(https://syzkaller.appspot.com/bug?extid=187510916eb6a14598f7).

Link: https://lore.kernel.org/r/20200628070057.820213-1-ebiggers@kernel.org
Reported-by: syzbot+187510916eb6a14598f7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/reiserfs/inode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 683496322aa8b..e7d02058eb611 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2164,7 +2164,8 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th,
out_inserted_sd:
clear_nlink(inode);
th->t_trans_id = 0; /* so the caller can't use this handle later */
- unlock_new_inode(inode); /* OK to do even if we hadn't locked it */
+ if (inode->i_state & I_NEW)
+ unlock_new_inode(inode);
iput(inode);
return err;
}
--
2.25.1