Merge tag 'driver-core-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull sysfs fixes from Greg Kroah-Hartman:
 "Here are two fixes for sysfs that resolve issues that have been found
  by the Trinity fuzz tool, causing oopses in sysfs.  They both have
  been in linux-next for a while to ensure that they do not cause any
  other problems."

* tag 'driver-core-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  sysfs: handle failure path correctly for readdir()
  sysfs: fix race between readdir and lseek

1 files changed, 16 insertions, 1 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 2fbdff6..e145126 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -1020,6 +1020,8 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 		ino = parent_sd->s_ino;
 		if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
 			filp->f_pos++;
+		else
+			return 0;
 	}
 	if (filp->f_pos == 1) {
 		if (parent_sd->s_parent)
@@ -1028,6 +1030,8 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 			ino = parent_sd->s_ino;
 		if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
 			filp->f_pos++;
+		else
+			return 0;
 	}
 	mutex_lock(&sysfs_mutex);
 	for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
@@ -1058,10 +1062,21 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
 	return 0;
 }
 
+static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file_inode(file);
+	loff_t ret;
+
+	mutex_lock(&inode->i_mutex);
+	ret = generic_file_llseek(file, offset, whence);
+	mutex_unlock(&inode->i_mutex);
+
+	return ret;
+}
 
 const struct file_operations sysfs_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= sysfs_readdir,
 	.release	= sysfs_dir_release,
-	.llseek		= generic_file_llseek,
+	.llseek		= sysfs_dir_llseek,
 };