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authorJeremy Allison <jra@samba.org>2004-09-04 01:57:16 +0000
committerGerald (Jerry) Carter <jerry@samba.org>2007-10-10 10:52:36 -0500
commit571cc4811bc373a5b4aeda9e5635aff1ff650e06 (patch)
tree77ddb35ff88a031e5666cbbb54f338f96dbdf6a6 /source3/nmbd
parentb755bdaa8eb7428e5da376762cd88ca416220682 (diff)
downloadsamba-571cc4811bc373a5b4aeda9e5635aff1ff650e06.tar.gz
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r2224: Make nmbd more robust against bad netbios packets.
Jeremy. (This used to be commit dd9b17abd6b32c090840c1a0b797fd774711cb3a)
Diffstat (limited to 'source3/nmbd')
-rw-r--r--source3/nmbd/nmbd_packets.c44
-rw-r--r--source3/nmbd/nmbd_processlogon.c104
2 files changed, 141 insertions, 7 deletions
diff --git a/source3/nmbd/nmbd_packets.c b/source3/nmbd/nmbd_packets.c
index d8b50a1b2e..96de4911dc 100644
--- a/source3/nmbd/nmbd_packets.c
+++ b/source3/nmbd/nmbd_packets.c
@@ -1203,6 +1203,16 @@ an error packet of type %x\n", nmb_namestr(&dgram->dest_name), inet_ntoa(p->ip),
return;
}
+ /* Ensure we have a large enough packet before looking inside. */
+ if (dgram->datasize < (smb_vwv12 - 2)) {
+ /* That's the offset minus the 4 byte length + 2 bytes of offset. */
+ DEBUG(0,("process_dgram: ignoring too short dgram packet (%u) sent to name %s from IP %s\n",
+ (unsigned int)dgram->datasize,
+ nmb_namestr(&dgram->dest_name),
+ inet_ntoa(p->ip) ));
+ return;
+ }
+
buf = &dgram->data[0];
buf -= 4; /* XXXX for the pseudo tcp length - someday I need to get rid of this */
@@ -1212,14 +1222,36 @@ an error packet of type %x\n", nmb_namestr(&dgram->dest_name), inet_ntoa(p->ip),
len = SVAL(buf,smb_vwv11);
buf2 = smb_base(buf) + SVAL(buf,smb_vwv12);
- if (len <= 0)
+ if (len <= 0 || len > dgram->datasize) {
+ DEBUG(0,("process_dgram: ignoring malformed1 (datasize = %d, len = %d) datagram \
+packet sent to name %s from IP %s\n",
+ dgram->datasize,
+ len,
+ nmb_namestr(&dgram->dest_name),
+ inet_ntoa(p->ip) ));
+ return;
+ }
+
+ if (buf2 < dgram->data || (buf2 >= dgram->data + dgram->datasize)) {
+ DEBUG(0,("process_dgram: ignoring malformed2 (datasize = %d, len=%d, off=%d) datagram \
+packet sent to name %s from IP %s\n",
+ dgram->datasize,
+ len,
+ PTR_DIFF(buf2, dgram->data),
+ nmb_namestr(&dgram->dest_name),
+ inet_ntoa(p->ip) ));
return;
+ }
- if (buf2 + len > buf + sizeof(dgram->data)) {
- DEBUG(2,("process_dgram: datagram from %s to %s IP %s for %s len=%d too long.\n",
- nmb_namestr(&dgram->source_name),nmb_namestr(&dgram->dest_name),
- inet_ntoa(p->ip), smb_buf(buf),len));
- len = (buf + sizeof(dgram->data)) - buf;
+ if ((buf2 + len < dgram->data) || (buf2 + len > dgram->data + dgram->datasize)) {
+ DEBUG(0,("process_dgram: ignoring malformed3 (datasize = %d, len=%d, off=%d) datagram \
+packet sent to name %s from IP %s\n",
+ dgram->datasize,
+ len,
+ PTR_DIFF(buf2, dgram->data),
+ nmb_namestr(&dgram->dest_name),
+ inet_ntoa(p->ip) ));
+ return;
}
DEBUG(4,("process_dgram: datagram from %s to %s IP %s for %s of type %d len=%d\n",
diff --git a/source3/nmbd/nmbd_processlogon.c b/source3/nmbd/nmbd_processlogon.c
index da93224043..fa2a8c1cef 100644
--- a/source3/nmbd/nmbd_processlogon.c
+++ b/source3/nmbd/nmbd_processlogon.c
@@ -102,8 +102,22 @@ logons are not enabled.\n", inet_ntoa(p->ip) ));
char *machine = q;
char *user = skip_string(machine,1);
+ if (PTR_DIFF(user, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
getdc = skip_string(user,1);
+
+ if (PTR_DIFF(getdc, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
q = skip_string(getdc,1);
+
+ if (PTR_DIFF(q + 5, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
token = SVAL(q,3);
fstrcpy(reply_name,my_name);
@@ -151,7 +165,17 @@ logons are not enabled.\n", inet_ntoa(p->ip) ));
}
getdc = skip_string(machine,1);
+
+ if (PTR_DIFF(getdc, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
q = skip_string(getdc,1);
+
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
q = ALIGN2(q, buf);
/* At this point we can work out if this is a W9X or NT style
@@ -165,9 +189,19 @@ logons are not enabled.\n", inet_ntoa(p->ip) ));
} else {
unicomp = q;
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
/* A full length (NT style) request */
q = skip_unibuf(unicomp, PTR_DIFF(buf + len, unicomp));
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
if (len - PTR_DIFF(q, buf) > 8) {
/* with NT5 clients we can sometimes
get additional data - a length specificed string
@@ -180,6 +214,12 @@ logons are not enabled.\n", inet_ntoa(p->ip) ));
}
q += 16;
}
+
+ if (PTR_DIFF(q + 8, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
ntversion = IVAL(q, 0);
lmnttoken = SVAL(q, 4);
lm20token = SVAL(q, 6);
@@ -240,10 +280,34 @@ reporting %s domain %s 0x%x ntversion=%x lm_nt token=%x lm_20 token=%x\n",
fstring asccomp;
q += 2;
+
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
unicomp = q;
uniuser = skip_unibuf(unicomp, PTR_DIFF(buf+len, unicomp));
+
+ if (PTR_DIFF(uniuser, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
getdc = skip_unibuf(uniuser,PTR_DIFF(buf+len, uniuser));
+
+ if (PTR_DIFF(getdc, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
q = skip_string(getdc,1);
+
+ if (PTR_DIFF(q + 8, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
q += 4; /* Account Control Bits - indicating username type */
domainsidsize = IVAL(q, 0);
q += 4;
@@ -270,6 +334,11 @@ reporting %s domain %s 0x%x ntversion=%x lm_nt token=%x lm_20 token=%x\n",
q += 16;
}
+ if (PTR_DIFF(q + 8, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
ntversion = IVAL(q, 0);
lmnttoken = SVAL(q, 4);
lm20token = SVAL(q, 6);
@@ -458,6 +527,11 @@ reporting %s domain %s 0x%x ntversion=%x lm_nt token=%x lm_20 token=%x\n",
/* Header */
+ if (PTR_DIFF(q + 16, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
low_serial = IVAL(q, 0); q += 4; /* Low serial number */
q += 4; /* Date/time */
@@ -467,14 +541,42 @@ reporting %s domain %s 0x%x ntversion=%x lm_nt token=%x lm_20 token=%x\n",
/* Domain info */
q = skip_string(q, 1); /* PDC name */
+
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
q = skip_string(q, 1); /* Domain name */
+
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
q = skip_unibuf(q, PTR_DIFF(buf + len, q)); /* Unicode PDC name */
+
+ if (PTR_DIFF(q, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
q = skip_unibuf(q, PTR_DIFF(buf + len, q)); /* Unicode domain name */
/* Database info */
+ if (PTR_DIFF(q + 2, buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
db_count = SVAL(q, 0); q += 2;
-
+
+ if (PTR_DIFF(q + (db_count*20), buf) >= len) {
+ DEBUG(0,("process_logon_packet: bad packet\n"));
+ return;
+ }
+
db_info = (struct sam_database_info *)
malloc(sizeof(struct sam_database_info) * db_count);