Commit e49452c6 authored Jan 16, 2008 by Tejun Heo Committed by Linus Torvalds Jan 16, 2008

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>

parent cbd9c883

fs/sysfs/dir.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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);