From: Paulo Alcantara <pc@manguebit.com>
Date: Fri, 19 Jan 2024 04:08:26 +0000 (-0300)
Subject: smb: client: fix parsing of SMB3.1.1 POSIX create context
X-Git-Tag: v6.7.3~285
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9201b54603496dc227ecc07bb6b8a78d5e711d8e;p=thirdparty%2Fkernel%2Fstable.git

smb: client: fix parsing of SMB3.1.1 POSIX create context

[ Upstream commit 76025cc2285d9ede3d717fe4305d66f8be2d9346 ]

The data offset for the SMB3.1.1 POSIX create context will always be
8-byte aligned so having the check 'noff + nlen >= doff' in
smb2_parse_contexts() is wrong as it will lead to -EINVAL because noff
+ nlen == doff.

Fix the sanity check to correctly handle aligned create context data.

Fixes: af1689a9b770 ("smb: client: fix potential OOBs in smb2_parse_contexts()")
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 4f971c1061f0a..12e41fcd0b46a 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -2279,7 +2279,7 @@ int smb2_parse_contexts(struct TCP_Server_Info *server,
 
 		noff = le16_to_cpu(cc->NameOffset);
 		nlen = le16_to_cpu(cc->NameLength);
-		if (noff + nlen >= doff)
+		if (noff + nlen > doff)
 			return -EINVAL;
 
 		name = (char *)cc + noff;