[PATCH] debugfs: fix double unlock in open_proxy_open()

[PATCH] debugfs: fix double unlock in open_proxy_open()

[Nicolai Stange]

In case an open is racing with a debugfs file removal, the corresponding
error path in open_proxy_open() releases its SRCU read side critical
section twice, i.e. it does a double unlock.

Fix that by purging the extra unlock operation.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
 fs/debugfs/file.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 6a4b667..9c1c9a0 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -108,7 +108,6 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
 
 	r = debugfs_use_file_start(dentry, &srcu_idx);
 	if (r) {
-		debugfs_use_file_finish(srcu_idx);
 		r = -ENOENT;
 		goto out;
 	}
-- 
2.7.2

Re: [PATCH] debugfs: fix double unlock in open_proxy_open()

[Nicolai Stange]

Nicolai Stange <nicstange@gmail.com> writes:

> In case an open is racing with a debugfs file removal, the corresponding
> error path in open_proxy_open() releases its SRCU read side critical
> section twice, i.e. it does a double unlock.


This one has been reported by Rasmus Villemoes:

  http://lkml.kernel.org/g/87d1r2uh95.fsf@rasmusvillemoes.dk


Thank you very much!

Nicolai

Re: [PATCH] debugfs: fix double unlock in open_proxy_open()

[Nicolai Stange]

Ah and sorry: applicable to the driver-core tree's driver-core-testing branch.

Re: [PATCH] debugfs: fix double unlock in open_proxy_open()

[Nicolai Stange]

Please drop as this has been fixed in the current v6 of the offending
series to be found here:

  http://lkml.kernel.org/g/1458652280-19785-1-git-send-email-nicstange@gmail.com

Thank you!

Nicolai