From: David Disseldorp <ddiss@suse.de>
Date: Wed, 3 May 2017 22:41:13 +0000 (+0200)
Subject: cifs: fix CIFS_IOC_GET_MNT_INFO oops
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~8^2~17
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9a40506699193a17bb5667f4f5036a63684a65fd;p=firefly-linux-kernel-4.4.55.git

cifs: fix CIFS_IOC_GET_MNT_INFO oops

commit d8a6e505d6bba2250852fbc1c1c86fe68aaf9af3 upstream.

An open directory may have a NULL private_data pointer prior to readdir.

Fixes: 0de1f4c6f6c0 ("Add way to query server fs info for smb3")
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>
---

diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index 35cf990f87d3..a8f5b31636dc 100644
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -272,6 +272,8 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
 				rc = -EOPNOTSUPP;
 			break;
 		case CIFS_IOC_GET_MNT_INFO:
+			if (pSMBFile == NULL)
+				break;
 			tcon = tlink_tcon(pSMBFile->tlink);
 			rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg);
 			break;