From e49452c67703d3647467d65275fb893589384fed Mon Sep 17 00:00:00 2001
From: Tejun Heo <htejun@gmail.com>
Date: Wed, 16 Jan 2008 12:06:14 +0900
Subject: [PATCH] sysfs: make sysfs_lookup() return ERR_PTR(-ENOENT) on failed
lookup
sysfs tries to keep dcache a strict subset of sysfs_dirent tree by
shooting down dentries when a node is removed, that is, no negative
dentry for sysfs. However, the lookup function returned NULL and thus
created negative dentries when the target node didn't exist.
Make sysfs_lookup() return ERR_PTR(-ENOENT) on lookup failure. This
fixes the NULL dereference bug in sysfs_get_dentry() discovered by
bluetooth rfcomm device moving around.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/sysfs/dir.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 337162935d21..b197016bbfbe 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -678,8 +678,10 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
/* no such entry */
- if (!sd)
+ if (!sd) {
+ ret = ERR_PTR(-ENOENT);
goto out_unlock;
+ }
/* attach dentry and inode */
inode = sysfs_get_inode(sd);
--
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