[PATCH 4.4 42/80] cifs: check kmalloc before use

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicholas Mc Guire <hofrat@xxxxxxxxx>

commit 126c97f4d0d1b5b956e8b0740c81a2b2a2ae548c upstream.

The kmalloc was not being checked - if it fails issue a warning
and return -ENOMEM to the caller.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Fixes: b8da344b74c8 ("cifs: dynamic allocation of ntlmssp blob")
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Reviewed-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
cc: Stable <stable@xxxxxxxxxxxxxxx>`
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/cifs/sess.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -398,6 +398,12 @@ int build_ntlmssp_auth_blob(unsigned cha
 		goto setup_ntlmv2_ret;
 	}
 	*pbuffer = kmalloc(size_of_ntlmssp_blob(ses), GFP_KERNEL);
+	if (!*pbuffer) {
+		rc = -ENOMEM;
+		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
+		*buflen = 0;
+		goto setup_ntlmv2_ret;
+	}
 	sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
 
 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);