sysfs: Fix oops in sysfs_drop_dentry on x86_64
Fix oops on x86_64 caused by the dereference of dir in
sysfs_drop_dentry() made before checking if dir is not NULL
(cf. http://marc.info/?l=linux-kernel&m=118151626704924&w=2).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 732fd7f..ee31bf3 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -285,7 +285,7 @@
int sysfs_hash_and_remove(struct dentry * dir, const char * name)
{
struct sysfs_dirent **pos, *sd;
- struct sysfs_dirent *parent_sd = dir->d_fsdata;
+ struct sysfs_dirent *parent_sd;
int found = 0;
if (!dir)
@@ -295,6 +295,7 @@
/* no inode means this hasn't been made visible yet */
return -ENOENT;
+ parent_sd = dir->d_fsdata;
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
sd = *pos;
