SMB3: Fix crash in SMB2_open_init due to uninitialized field in compounding path

Ran into an intermittent crash in
	SMB2_open_init+0x2f6/0x970
due to oparms.cifs_sb not being initialized when called from:
	smb2_compound_op+0x45d/0x1690
Zero the whole oparms struct in the compounding path before setting up the
oparms so we don't risk any uninitialized fields.

Fixes: 7190c76d4cc6 ("smb3: fix mode passed in on create for modetosid mount option")
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 18c7a33adcebf36b7908566897de44a1de683c46..5ef5e97a6d13eb8171c5b49ce2f02096dc18a391 100644 (file)
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -95,6 +95,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
                goto finished;
        }
 
+       memset(&oparms, 0, sizeof(struct cifs_open_parms));
        oparms.tcon = tcon;
        oparms.desired_access = desired_access;
        oparms.disposition = create_disposition;