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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Paulo Alcantara <pc@manguebit.com>,
	j51569436@gmail.com,
	Steve French <stfrench@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	sfrench@samba.org,
	linux-cifs@vger.kernel.org,
	samba-technical@lists.samba.org
Subject: [PATCH AUTOSEL 6.1 18/24] smb: client: fix potential OOB in smb2_dump_detail()
Date: Mon, 25 Dec 2023 19:22:11 -0500
Message-ID: <20231226002255.5730-18-sashal@kernel.org>
In-Reply-To: <20231226002255.5730-1-sashal@kernel.org>
References: <20231226002255.5730-1-sashal@kernel.org>
Precedence: bulk
MIME-Version: 1.0
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From: Paulo Alcantara <pc@manguebit.com>

[ Upstream commit 567320c46a60a3c39b69aa1df802d753817a3f86 ]

Validate SMB message with ->check_message() before calling
->calc_smb_size().

This fixes CVE-2023-6610.

Reported-by: j51569436@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218219
Cc; stable@vger.kernel.org
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/client/smb2misc.c | 30 +++++++++++++++---------------
 fs/smb/client/smb2ops.c  |  6 ++++--
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/fs/smb/client/smb2misc.c b/fs/smb/client/smb2misc.c
index 88942b1fb4318..08ad74f51964f 100644
--- a/fs/smb/client/smb2misc.c
+++ b/fs/smb/client/smb2misc.c
@@ -173,6 +173,21 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 	}
 
 	mid = le64_to_cpu(shdr->MessageId);
+	if (check_smb2_hdr(shdr, mid))
+		return 1;
+
+	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
+		cifs_dbg(VFS, "Invalid structure size %u\n",
+			 le16_to_cpu(shdr->StructureSize));
+		return 1;
+	}
+
+	command = le16_to_cpu(shdr->Command);
+	if (command >= NUMBER_OF_SMB2_COMMANDS) {
+		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
+		return 1;
+	}
+
 	if (len < pdu_size) {
 		if ((len >= hdr_size)
 		    && (shdr->Status != 0)) {
@@ -193,21 +208,6 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 		return 1;
 	}
 
-	if (check_smb2_hdr(shdr, mid))
-		return 1;
-
-	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
-		cifs_dbg(VFS, "Invalid structure size %u\n",
-			 le16_to_cpu(shdr->StructureSize));
-		return 1;
-	}
-
-	command = le16_to_cpu(shdr->Command);
-	if (command >= NUMBER_OF_SMB2_COMMANDS) {
-		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
-		return 1;
-	}
-
 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 1b3489a2f0db7..a9f84664a7a83 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -398,8 +398,10 @@ smb2_dump_detail(void *buf, struct TCP_Server_Info *server)
 	cifs_server_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d\n",
 		 shdr->Command, shdr->Status, shdr->Flags, shdr->MessageId,
 		 shdr->Id.SyncId.ProcessId);
-	cifs_server_dbg(VFS, "smb buf %p len %u\n", buf,
-		 server->ops->calc_smb_size(buf));
+	if (!server->ops->check_message(buf, server->total_read, server)) {
+		cifs_server_dbg(VFS, "smb buf %p len %u\n", buf,
+				server->ops->calc_smb_size(buf));
+	}
 #endif
 }
 
-- 
2.43.0