From: Ronnie Sahlberg lsahlber@redhat.com
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@redhat.com Cc: stable@vger.kernel.org Reviewed-by: Shyam Prasad N sprasad@microsoft.com Reported-by: Xiaoli Feng xifeng@redhat.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 */