linux-kernel - [PATCH 04/11] fuse: fix O_EXCL in fuse_atomic

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Message-Id: <1379335925-30858-5-git-send-email-miklos@szeredi.hu>
Date:	Mon, 16 Sep 2013 14:51:58 +0200
From:	Miklos Szeredi <miklos@...redi.hu>
To:	viro@...IV.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	mszeredi@...e.cz, stable@...r.kernel.org
Subject: [PATCH 04/11] fuse: fix O_EXCL in fuse_atomic_open()

From: Miklos Szeredi <mszeredi@...e.cz>

If open flags has O_EXCL and dentry is positive after lookup then return
-EEXIST instead of "1".

This bug resulted in some O_EXCL opens succeeding (on a cache miss) despite
the file already existing.

Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
Cc: stable@...r.kernel.org
---
 fs/fuse/dir.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 62b43b5..694ec6b 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -523,9 +523,17 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 			entry = res;
 	}
 
-	if (!(flags & O_CREAT) || entry->d_inode)
+	if (!(flags & O_CREAT))
 		goto no_open;
 
+	if (entry->d_inode) {
+		err = -EEXIST;
+		if (flags & O_EXCL)
+			goto out_dput;
+
+		goto no_open;
+	}
+
 	/* Only creates */
 	*opened |= FILE_CREATED;
 
-- 
1.8.1.4

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