Security fix for CVE-2008-1105: Boundary failure when parsing SMB responses

can result in a buffer overrun.
Jeremy.
(This used to be commit 23b825e9d2c74c5b940cf4d3aa56c18692259972)

7 files changed, 20 insertions, 212 deletions

diff --git a/source3/client/client.c b/source3/client/client.c
index cc0da18d4d..8c939fc3ec 100644
--- a/source3/client/client.c
+++ b/source3/client/client.c
@@ -4382,7 +4382,7 @@ static void readline_callback(void)
 
 		set_smb_read_error(&cli->smb_rw_error, SMB_READ_OK);
 
-		status = receive_smb_raw(cli->fd, cli->inbuf, 0, 0, &len);
+		status = receive_smb_raw(cli->fd, cli->inbuf, cli->bufsize, 0, 0, &len);
 
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(0, ("Read from server failed, maybe it closed "
diff --git a/source3/include/proto.h b/source3/include/proto.h
index 36d75a4d75..761c720497 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -1582,8 +1582,12 @@ NTSTATUS read_smb_length_return_keepalive(int fd, char *inbuf,
 					  size_t *len);
 NTSTATUS read_smb_length(int fd, char *inbuf, unsigned int timeout,
 			 size_t *len);
-NTSTATUS receive_smb_raw(int fd, char *buffer, unsigned int timeout,
-			 size_t maxlen, size_t *p_len);
+NTSTATUS receive_smb_raw(int fd,
+			char *buffer,
+			size_t buflen,
+			unsigned int timeout,
+			size_t maxlen,
+			size_t *p_len);
 int open_socket_in(int type,
 		uint16_t port,
 		int dlevel,
diff --git a/source3/lib/util_sock.c b/source3/lib/util_sock.c
index f252377b7e..b2a1ece5db 100644
--- a/source3/lib/util_sock.c
+++ b/source3/lib/util_sock.c
@@ -1151,16 +1151,15 @@ NTSTATUS read_smb_length(int fd, char *inbuf, unsigned int timeout,
 }
 
 /****************************************************************************
- Read an smb from a fd. Note that the buffer *MUST* be of size
- BUFFER_SIZE+SAFETY_MARGIN.
+ Read an smb from a fd.
  The timeout is in milliseconds.
  This function will return on receipt of a session keepalive packet.
  maxlen is the max number of bytes to return, not including the 4 byte
- length. If zero it means BUFFER_SIZE+SAFETY_MARGIN limit.
+ length. If zero it means buflen limit.
  Doesn't check the MAC on signed packets.
 ****************************************************************************/
 
-NTSTATUS receive_smb_raw(int fd, char *buffer, unsigned int timeout,
+NTSTATUS receive_smb_raw(int fd, char *buffer, size_t buflen, unsigned int timeout,
 			 size_t maxlen, size_t *p_len)
 {
 	size_t len;
@@ -1173,17 +1172,10 @@ NTSTATUS receive_smb_raw(int fd, char *buffer, unsigned int timeout,
 		return status;
 	}
 
-	/*
-	 * A WRITEX with CAP_LARGE_WRITEX can be 64k worth of data plus 65 bytes
-	 * of header. Don't print the error if this fits.... JRA.
-	 */
-
-	if (len > (BUFFER_SIZE + LARGE_WRITEX_HDR_SIZE)) {
+	if (len > buflen) {
 		DEBUG(0,("Invalid packet length! (%lu bytes).\n",
 					(unsigned long)len));
-		if (len > BUFFER_SIZE + (SAFETY_MARGIN/2)) {
-			return NT_STATUS_INVALID_PARAMETER;
-		}
+		return NT_STATUS_INVALID_PARAMETER;
 	}
 
 	if(len > 0) {
diff --git a/source3/libsmb/clientgen.c b/source3/libsmb/clientgen.c
index e64b6fa278..60ec632b83 100644
--- a/source3/libsmb/clientgen.c
+++ b/source3/libsmb/clientgen.c
@@ -57,8 +57,7 @@ int cli_set_port(struct cli_state *cli, int port)
 }
 
 /****************************************************************************
- Read an smb from a fd ignoring all keepalive packets. Note that the buffer 
- *MUST* be of size BUFFER_SIZE+SAFETY_MARGIN.
+ Read an smb from a fd ignoring all keepalive packets.
  The timeout is in milliseconds
 
  This is exactly the same as receive_smb except that it never returns
@@ -76,8 +75,8 @@ static ssize_t client_receive_smb(struct cli_state *cli, size_t maxlen)
 
 		set_smb_read_error(&cli->smb_rw_error, SMB_READ_OK);
 
-		status = receive_smb_raw(cli->fd, cli->inbuf, cli->timeout,
-					 maxlen, &len);
+		status = receive_smb_raw(cli->fd, cli->inbuf, cli->bufsize,
+					cli->timeout, maxlen, &len);
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(10,("client_receive_smb failed\n"));
 			show_msg(cli->inbuf);
@@ -225,93 +224,6 @@ ssize_t cli_receive_smb_data(struct cli_state *cli, char *buffer, size_t len)
 	return -1;
 }
 
-/****************************************************************************
- Read a smb readX header.
- We can only use this if encryption and signing are off.
-****************************************************************************/
-
-bool cli_receive_smb_readX_header(struct cli_state *cli)
-{
-	ssize_t len, offset;
-
-	if (cli->fd == -1)
-		return false; 
-
- again:
-
-	/* Read up to the size of a readX header reply. */
-	len = client_receive_smb(cli, (smb_size - 4) + 24);
-	
-	if (len > 0) {
-		/* it might be an oplock break request */
-		if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) &&
-		    CVAL(cli->inbuf,smb_com) == SMBlockingX &&
-		    SVAL(cli->inbuf,smb_vwv6) == 0 &&
-		    SVAL(cli->inbuf,smb_vwv7) == 0) {
-			ssize_t total_len = smb_len(cli->inbuf);
-
-			if (total_len > CLI_SAMBA_MAX_LARGE_READX_SIZE+SAFETY_MARGIN) {
-				goto read_err;
-			}
-
-			/* Read the rest of the data. */
-			if ((total_len - len > 0) &&
-			    !cli_receive_smb_data(cli,cli->inbuf+len,total_len - len)) {
-				goto read_err;
-			}
-
-			if (cli->oplock_handler) {
-				int fnum = SVAL(cli->inbuf,smb_vwv2);
-				unsigned char level = CVAL(cli->inbuf,smb_vwv3+1);
-				if (!cli->oplock_handler(cli, fnum, level)) return false;
-			}
-			/* try to prevent loops */
-			SCVAL(cli->inbuf,smb_com,0xFF);
-			goto again;
-		}
-	}
-
-	/* If it's not the above size it probably was an error packet. */
-
-	if ((len == (smb_size - 4) + 24) && !cli_is_error(cli)) {
-		/* Check it's a non-chained readX reply. */
-		if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) ||
-			(CVAL(cli->inbuf,smb_vwv0) != 0xFF) ||
-			(CVAL(cli->inbuf,smb_com) != SMBreadX)) {
-			/* 
-			 * We're not coping here with asnyc replies to
-			 * other calls. Punt here - we need async client
-			 * libs for this.
-			 */
-			goto read_err;
-		}
-
-		/* 
-		 * We know it's a readX reply - ensure we've read the
-		 * padding bytes also.
-		 */
-
-		offset = SVAL(cli->inbuf,smb_vwv6);
-		if (offset > len) {
-			ssize_t ret;
-			size_t padbytes = offset - len;
-			ret = cli_receive_smb_data(cli,smb_buf(cli->inbuf),padbytes);
-			if (ret != padbytes) {
-				goto read_err;
-			}
-		}
-	}
-
-	return true;
-
-  read_err:
-
-	cli->smb_rw_error = SMB_READ_ERROR;
-	close(cli->fd);
-	cli->fd = -1;
-	return false;
-}
-
 static ssize_t write_socket(int fd, const char *buf, size_t len)
 {
         ssize_t ret=0;
diff --git a/source3/libsmb/clireadwrite.c b/source3/libsmb/clireadwrite.c
index 515471e003..057e647983 100644
--- a/source3/libsmb/clireadwrite.c
+++ b/source3/libsmb/clireadwrite.c
@@ -472,106 +472,6 @@ ssize_t cli_read(struct cli_state *cli, int fnum, char *buf,
 	return ret;
 }
 
-#if 0  /* relies on client_receive_smb(), now a static in libsmb/clientgen.c */
-
-/* This call is INCOMPATIBLE with SMB signing.  If you remove the #if 0
-   you must fix ensure you don't attempt to sign the packets - data
-   *will* be currupted */
-
-/****************************************************************************
-Issue a single SMBreadraw and don't wait for a reply.
-****************************************************************************/
-
-static bool cli_issue_readraw(struct cli_state *cli, int fnum, off_t offset, 
-			   size_t size, int i)
-{
-
-	if (!cli->sign_info.use_smb_signing) {
-		DEBUG(0, ("Cannot use readraw and SMB Signing\n"));
-		return False;
-	}
-	
-	memset(cli->outbuf,'\0',smb_size);
-	memset(cli->inbuf,'\0',smb_size);
-
-	cli_set_message(cli->outbuf,10,0,True);
-		
-	SCVAL(cli->outbuf,smb_com,SMBreadbraw);
-	SSVAL(cli->outbuf,smb_tid,cli->cnum);
-	cli_setup_packet(cli);
-
-	SSVAL(cli->outbuf,smb_vwv0,fnum);
-	SIVAL(cli->outbuf,smb_vwv1,offset);
-	SSVAL(cli->outbuf,smb_vwv2,size);
-	SSVAL(cli->outbuf,smb_vwv3,size);
-	SSVAL(cli->outbuf,smb_mid,cli->mid + i);
-
-	return cli_send_smb(cli);
-}
-
-/****************************************************************************
- Tester for the readraw call.
-****************************************************************************/
-
-ssize_t cli_readraw(struct cli_state *cli, int fnum, char *buf, off_t offset, size_t size)
-{
-	char *p;
-	int size2;
-	size_t readsize;
-	ssize_t total = 0;
-
-	if (size == 0) 
-		return 0;
-
-	/*
-	 * Set readsize to the maximum size we can handle in one readraw.
-	 */
-
-	readsize = 0xFFFF;
-
-	while (total < size) {
-		readsize = MIN(readsize, size-total);
-
-		/* Issue a read and receive a reply */
-
-		if (!cli_issue_readraw(cli, fnum, offset, readsize, 0))
-			return -1;
-
-		if (!client_receive_smb(cli->fd, cli->inbuf, cli->timeout))
-			return -1;
-
-		size2 = smb_len(cli->inbuf);
-
-		if (size2 > readsize) {
-			DEBUG(5,("server returned more than we wanted!\n"));
-			return -1;
-		} else if (size2 < 0) {
-			DEBUG(5,("read return < 0!\n"));
-			return -1;
-		}
-
-		/* Copy data into buffer */
-
-		if (size2) {
-			p = cli->inbuf + 4;
-			memcpy(buf + total, p, size2);
-		}
-
-		total += size2;
-		offset += size2;
-
-		/*
-		 * If the server returned less than we asked for we're at EOF.
-		 */
-
-		if (size2 < readsize)
-			break;
-	}
-
-	return total;
-}
-#endif
-
 /****************************************************************************
  Issue a single SMBwrite and don't wait for a reply.
 ****************************************************************************/
diff --git a/source3/smbd/process.c b/source3/smbd/process.c
index c8ad19dd15..71e38634b7 100644
--- a/source3/smbd/process.c
+++ b/source3/smbd/process.c
@@ -120,9 +120,7 @@ static bool valid_packet_size(size_t len)
 	if (len > (BUFFER_SIZE + LARGE_WRITEX_HDR_SIZE)) {
 		DEBUG(0,("Invalid packet length! (%lu bytes).\n",
 					(unsigned long)len));
-		if (len > BUFFER_SIZE + (SAFETY_MARGIN/2)) {
-			return false;
-		}
+		return false;
 	}
 	return true;
 }
diff --git a/source3/utils/smbfilter.c b/source3/utils/smbfilter.c
index e128e1ce34..d274e09299 100644
--- a/source3/utils/smbfilter.c
+++ b/source3/utils/smbfilter.c
@@ -171,7 +171,8 @@ static void filter_child(int c, struct sockaddr_storage *dest_ss)
 		if (c != -1 && FD_ISSET(c, &fds)) {
 			size_t len;
 			if (!NT_STATUS_IS_OK(receive_smb_raw(
-						     c, packet, 0, 0, &len))) {
+							c, packet, sizeof(packet),
+							0, 0, &len))) {
 				d_printf("client closed connection\n");
 				exit(0);
 			}
@@ -184,7 +185,8 @@ static void filter_child(int c, struct sockaddr_storage *dest_ss)
 		if (s != -1 && FD_ISSET(s, &fds)) {
 			size_t len;
 			if (!NT_STATUS_IS_OK(receive_smb_raw(
-						     s, packet, 0, 0, &len))) {
+							s, packet, sizeof(packet),
+							0, 0, &len))) {
 				d_printf("server closed connection\n");
 				exit(0);
 			}