reiserfs: only call unlock_new_inode() if I_NEW

Commit Message

Eric Biggers June 28, 2020, 7 a.m. UTC

From: Eric Biggers <[e-mail]>

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).

Reported-by: [e-mail]
Signed-off-by: Eric Biggers <[e-mail]>
---
 fs/reiserfs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Eric Biggers July 27, 2020, 4:52 p.m. UTC | #1

On Sun, Jun 28, 2020 at 12:00:57AM -0700, Eric Biggers wrote:
> From: Eric Biggers <[e-mail]>
> 
> 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).
> 
> Reported-by: [e-mail]
> Signed-off-by: Eric Biggers <[e-mail]>

Anyone interested in taking this patch?

- Eric

Eric Biggers Sept. 16, 2020, 4:01 a.m. UTC | #2

On Mon, Jul 27, 2020 at 09:52:15AM -0700, Eric Biggers wrote:
> On Sun, Jun 28, 2020 at 12:00:57AM -0700, Eric Biggers wrote:
> > From: Eric Biggers <[e-mail]>
> > 
> > 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).
> > 
> > Reported-by: [e-mail]
> > Signed-off-by: Eric Biggers <[e-mail]>
> 
> Anyone interested in taking this patch?

Jan, you seem to be taking some reiserfs patches... Any interest in taking this
one?

- Eric

Jan Kara Sept. 16, 2020, 10:54 a.m. UTC | #3

On Tue 15-09-20 21:01:18, Eric Biggers wrote:
> On Mon, Jul 27, 2020 at 09:52:15AM -0700, Eric Biggers wrote:
> > On Sun, Jun 28, 2020 at 12:00:57AM -0700, Eric Biggers wrote:
> > > From: Eric Biggers <[e-mail]>
> > > 
> > > 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).
> > > 
> > > Reported-by: [e-mail]
> > > Signed-off-by: Eric Biggers <[e-mail]>
> > 
> > Anyone interested in taking this patch?
> 
> Jan, you seem to be taking some reiserfs patches... Any interest in
> taking this one?

Sure, the patch looks good to me so I've added it to my tree. Thanks!

								Honza

Patch

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 1509775da040..e3af44c61524 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2163,7 +2163,8 @@  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;
 }