From: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
commit 8b6c58458ee3206dde345fce327a4cb83e69caf9 upstream.
On umount, cifs_sb->tlink_tree might contain entries that do not represent
a valid tcon.
Check the tcon for error before we dereference it.
Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Reported-by: Xiaoli Feng <xifeng@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/cifsfs.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -266,10 +266,11 @@ static void cifs_kill_sb(struct super_bl
* before we kill the sb.
*/
if (cifs_sb->root) {
- node = rb_first(root);
- while (node != NULL) {
+ for (node = rb_first(root); node; node = rb_next(node)) {
tlink = rb_entry(node, struct tcon_link, tl_rbnode);
tcon = tlink_tcon(tlink);
+ if (IS_ERR(tcon))
+ continue;
cfid = &tcon->crfid;
mutex_lock(&cfid->fid_mutex);
if (cfid->dentry) {
@@ -277,7 +278,6 @@ static void cifs_kill_sb(struct super_bl
cfid->dentry = NULL;
}
mutex_unlock(&cfid->fid_mutex);
- node = rb_next(node);
}
/* finally release root dentry */
