[PATCH] smb: client: fix oops due to uninitialised var in smb2_unlink()

[Paulo Alcantara <pc@manguebit.org>]

If SMB2_open_init() or SMB2_close_init() fails (e.g. reconnect), the
iovs set @rqst will be left uninitialised, hence calling
SMB2_open_free(), SMB2_close_free() or smb2_set_related() on them will
oops.

Fix this by initialising @close_iov and @open_iov before setting them
in @rqst.

Reported-by: Thiago Becker <tbecker@redhat.com>
Fixes: 1cf9f2a6a544 ("smb: client: handle unlink(2) of files open by different clients")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
---
 fs/smb/client/smb2inode.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
index 1c4663ed7e69..5280c5c869ad 100644
--- a/fs/smb/client/smb2inode.c
+++ b/fs/smb/client/smb2inode.c
@@ -1216,6 +1216,7 @@ smb2_unlink(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
 	memset(resp_buftype, 0, sizeof(resp_buftype));
 	memset(rsp_iov, 0, sizeof(rsp_iov));
 
+	memset(open_iov, 0, sizeof(open_iov));
 	rqst[0].rq_iov = open_iov;
 	rqst[0].rq_nvec = ARRAY_SIZE(open_iov);
 
@@ -1240,14 +1241,15 @@ smb2_unlink(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
 	creq = rqst[0].rq_iov[0].iov_base;
 	creq->ShareAccess = FILE_SHARE_DELETE_LE;
 
+	memset(&close_iov, 0, sizeof(close_iov));
 	rqst[1].rq_iov = &close_iov;
 	rqst[1].rq_nvec = 1;
 
 	rc = SMB2_close_init(tcon, server, &rqst[1],
 			     COMPOUND_FID, COMPOUND_FID, false);
+	if (rc)
+		goto err_free;
 	smb2_set_related(&rqst[1]);
-	if (rc)
-		goto err_free;
 
 	if (retries) {
 		/* Back-off before retry */
-- 
2.53.0