cifs: fix CIFS_ENUMERATE_SNAPSHOTS oops

commit 6026685de3 upstream.

As with 618763958b, an open directory may have a NULL private_data
pointer prior to readdir. CIFS_ENUMERATE_SNAPSHOTS must check for this
before dereference.

Fixes: 834170c859 ("Enable previous version support")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Disseldorp
2017-05-03 17:39:08 +02:00
committed by Greg Kroah-Hartman
parent 449a74439d
commit 411346640c

View File

@@ -268,6 +268,8 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg);
break;
case CIFS_ENUMERATE_SNAPSHOTS:
if (pSMBFile == NULL)
break;
if (arg == 0) {
rc = -EINVAL;
goto cifs_ioc_exit;