From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 14 Jan 2021 16:32:15 +0000 (+0100)
Subject: libcli/smb: allow unexpected padding in SMB2 IOCTL responses
X-Git-Tag: samba-4.12.12~40
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=552548ff00e08ba4639b2a9b1ef978259cdb7c1a;p=thirdparty%2Fsamba.git

libcli/smb: allow unexpected padding in SMB2 IOCTL responses

A NetApp Ontap 7.3.7 SMB server add 8 padding bytes to an
offset that's already 8 byte aligned.

RN: Work around special SMB2 IOCTL response behavior of NetApp Ontap 7.3.7
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14607

Pair-Programmed-With: Volker Lendecke <vl@samba.org>

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Jan 15 08:36:34 UTC 2021 on sn-devel-184

(cherry picked from commit 4c6c71e1378401d66bf2ed230544a75f7b04376f)

Autobuild-User(v4-12-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-12-test): Mon Jan 18 08:57:48 UTC 2021 on sn-devel-184
---

diff --git a/libcli/smb/smb2cli_ioctl.c b/libcli/smb/smb2cli_ioctl.c
index 6368bd31bc2..f9abcc57bab 100644
--- a/libcli/smb/smb2cli_ioctl.c
+++ b/libcli/smb/smb2cli_ioctl.c
@@ -191,8 +191,25 @@ static NTSTATUS smb2cli_ioctl_parse_buffer(uint32_t dyn_offset,
 		return NT_STATUS_OK;
 	}
 
+	if ((buffer_offset % 8) != 0) {
+		/*
+		 * The offset needs to be 8 byte aligned.
+		 */
+		return NT_STATUS_INVALID_NETWORK_RESPONSE;
+	}
+
+	/*
+	 * We used to enforce buffer_offset to be
+	 * an exact match of the expected minimum,
+	 * but the NetApp Ontap 7.3.7 SMB server
+	 * gets the padding wrong and aligns the
+	 * input_buffer_offset by a value of 8.
+	 *
+	 * So we just enforce that the offset is
+	 * not lower than the expected value.
+	 */
 	SMB_ASSERT(min_offset >= dyn_offset);
-	if (buffer_offset != min_offset) {
+	if (buffer_offset < min_offset) {
 		return NT_STATUS_INVALID_NETWORK_RESPONSE;
 	}