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

can result in a buffer overrun.
Jeremy.
(This used to be commit 23b825e9d2)
This commit is contained in:
Jeremy Allison 2008-05-28 09:31:42 -07:00
parent 611072fc1c
commit d36434f312
7 changed files with 20 additions and 212 deletions

View File

@ -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 "

View File

@ -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,

View File

@ -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) {

View File

@ -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;

View File

@ -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.
****************************************************************************/

View File

@ -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;
}

View File

@ -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);
}