On Sat, 12 Aug 2017 at 15:33:34 +0200, Moritz Mühlenhoff wrote:
> Feel free to simply upload an untested package for jessie-security,
> I'm flying back on Sunday evening, I can run tests on jessie sometime
> next week.
I was able to do a smoke-test on a virtual machine (llvmpipe is much
better than I remembered, apparently) so there is now a briefly tested
jessie-security version in the queue. Any additional testing would
likely be useful - the patch is to netcode, so hosting or joining an
openarena server is an appropriate test. See attached debdiff.
S
diffstat for ioquake3-1.36+u20140802+gca9eebb ioquake3-1.36+u20140802+gca9eebb
changelog | 10
patches/security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch | 213 ++++++++++
patches/series | 1
3 files changed, 224 insertions(+)
diff -Nru ioquake3-1.36+u20140802+gca9eebb/debian/changelog ioquake3-1.36+u20140802+gca9eebb/debian/changelog
--- ioquake3-1.36+u20140802+gca9eebb/debian/changelog 2017-03-14 18:29:48.000000000 -0400
+++ ioquake3-1.36+u20140802+gca9eebb/debian/changelog 2017-08-12 10:15:49.000000000 -0400
@@ -1,3 +1,13 @@
+ioquake3 (1.36+u20140802+gca9eebb-2+deb8u2) jessie-security; urgency=medium
+
+ * Add patch from upstream:
+ + Address read buffer overflow in
+ MSG_ReadBits (CVE-2017-11721) (Closes: #870725)
+ + Check buffer boundary exactly in MSG_WriteBits, instead of
+ potentially failing with a few bytes still available
+
+ -- Simon McVittie <s...@debian.org> Sat, 12 Aug 2017 10:15:49 -0400
+
ioquake3 (1.36+u20140802+gca9eebb-2+deb8u1) jessie-security; urgency=high
* d/gbp.conf: switch branch to debian/jessie
diff -Nru ioquake3-1.36+u20140802+gca9eebb/debian/patches/security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch ioquake3-1.36+u20140802+gca9eebb/debian/patches/security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch
--- ioquake3-1.36+u20140802+gca9eebb/debian/patches/security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch 1969-12-31 19:00:00.000000000 -0500
+++ ioquake3-1.36+u20140802+gca9eebb/debian/patches/security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch 2017-08-12 10:15:49.000000000 -0400
@@ -0,0 +1,213 @@
+From: Zack Middleton <z...@cloemail.com>
+Date: Wed, 2 Aug 2017 14:55:10 -0500
+Subject: Fix/improve buffer overflow in MSG_ReadBits/MSG_WriteBits
+
+Prevent reading past end of message in MSG_ReadBits. If read past
+end of msg->data buffer (16348 bytes) the engine could SEGFAULT.
+Make MSG_WriteBits use an exact buffer overflow check instead of
+possibly failing with a few bytes left.
+
+Origin: upstream, commit:d2b1d124d4055c2fcbe5126863487c52fd58cca1
+Bug-CVE: CVE-2017-11721
+Bug-Debian: https://bugs.debian.org/870725
+---
+ code/qcommon/huffman.c | 27 ++++++++++++++++++---------
+ code/qcommon/msg.c | 40 +++++++++++++++++++++++++++++++++++-----
+ code/qcommon/qcommon.h | 6 +++---
+ 3 files changed, 56 insertions(+), 17 deletions(-)
+
+diff --git a/code/qcommon/huffman.c b/code/qcommon/huffman.c
+index c1b9f24..1f42498 100644
+--- a/code/qcommon/huffman.c
++++ b/code/qcommon/huffman.c
+@@ -279,9 +279,14 @@ int Huff_Receive (node_t *node, int *ch, byte *fin) {
+ }
+
+ /* Get a symbol */
+-void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset) {
++void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset, int maxoffset) {
+ bloc = *offset;
+ while (node && node->symbol == INTERNAL_NODE) {
++ if (bloc >= maxoffset) {
++ *ch = 0;
++ *offset = maxoffset + 1;
++ return;
++ }
+ if (get_bit(fin)) {
+ node = node->right;
+ } else {
+@@ -298,11 +303,15 @@ void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset) {
+ }
+
+ /* Send the prefix code for this node */
+-static void send(node_t *node, node_t *child, byte *fout) {
++static void send(node_t *node, node_t *child, byte *fout, int maxoffset) {
+ if (node->parent) {
+- send(node->parent, node, fout);
++ send(node->parent, node, fout, maxoffset);
+ }
+ if (child) {
++ if (bloc >= maxoffset) {
++ bloc = maxoffset + 1;
++ return;
++ }
+ if (node->right == child) {
+ add_bit(1, fout);
+ } else {
+@@ -312,22 +321,22 @@ static void send(node_t *node, node_t *child, byte *fout) {
+ }
+
+ /* Send a symbol */
+-void Huff_transmit (huff_t *huff, int ch, byte *fout) {
++void Huff_transmit (huff_t *huff, int ch, byte *fout, int maxoffset) {
+ int i;
+ if (huff->loc[ch] == NULL) {
+ /* node_t hasn't been transmitted, send a NYT, then the symbol */
+- Huff_transmit(huff, NYT, fout);
++ Huff_transmit(huff, NYT, fout, maxoffset);
+ for (i = 7; i >= 0; i--) {
+ add_bit((char)((ch >> i) & 0x1), fout);
+ }
+ } else {
+- send(huff->loc[ch], NULL, fout);
++ send(huff->loc[ch], NULL, fout, maxoffset);
+ }
+ }
+
+-void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset) {
++void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset, int maxoffset) {
+ bloc = *offset;
+- send(huff->loc[ch], NULL, fout);
++ send(huff->loc[ch], NULL, fout, maxoffset);
+ *offset = bloc;
+ }
+
+@@ -413,7 +422,7 @@ void Huff_Compress(msg_t *mbuf, int offset) {
+
+ for (i=0; i<size; i++ ) {
+ ch = buffer[i];
+- Huff_transmit(&huff, ch, seq); /* Transmit symbol */
++ Huff_transmit(&huff, ch, seq, size<<3); /* Transmit symbol */
+ Huff_addRef(&huff, (byte)ch); /* Do update */
+ }
+
+diff --git a/code/qcommon/msg.c b/code/qcommon/msg.c
+index 5623b9b..ac7a954 100644
+--- a/code/qcommon/msg.c
++++ b/code/qcommon/msg.c
+@@ -110,9 +110,7 @@ void MSG_WriteBits( msg_t *msg, int value, int bits ) {
+
+ oldsize += bits;
+
+- // this isn't an exact overflow check, but close enough
+- if ( msg->maxsize - msg->cursize < 4 ) {
+- msg->overflowed = qtrue;
++ if ( msg->overflowed ) {
+ return;
+ }
+
+@@ -140,6 +138,11 @@ void MSG_WriteBits( msg_t *msg, int value, int bits ) {
+ bits = -bits;
+ }
+ if (msg->oob) {
++ if ( msg->cursize + ( bits >> 3 ) > msg->maxsize ) {
++ msg->overflowed = qtrue;
++ return;
++ }
++
+ if(bits==8)
+ {
+ msg->data[msg->cursize] = value;
+@@ -168,6 +171,10 @@ void MSG_WriteBits( msg_t *msg, int value, int bits ) {
+ if (bits&7) {
+ int nbits;
+ nbits = bits&7;
++ if ( msg->bit + nbits > msg->maxsize << 3 ) {
++ msg->overflowed = qtrue;
++ return;
++ }
+ for(i=0;i<nbits;i++) {
+ Huff_putBit((value&1), msg->data, &msg->bit);
+ value = (value>>1);
+@@ -177,8 +184,13 @@ void MSG_WriteBits( msg_t *msg, int value, int bits ) {
+ if (bits) {
+ for(i=0;i<bits;i+=8) {
+ // fwrite(bp, 1, 1, fp);
+- Huff_offsetTransmit (&msgHuff.compressor, (value&0xff), msg->data, &msg->bit);
++ Huff_offsetTransmit( &msgHuff.compressor, (value & 0xff), msg->data, &msg->bit, msg->maxsize << 3 );
+ value = (value>>8);
++
++ if ( msg->bit > msg->maxsize << 3 ) {
++ msg->overflowed = qtrue;
++ return;
++ }
+ }
+ }
+ msg->cursize = (msg->bit>>3)+1;
+@@ -193,6 +205,10 @@ int MSG_ReadBits( msg_t *msg, int bits ) {
+ int i, nbits;
+ // FILE* fp;
+
++ if ( msg->readcount > msg->cursize ) {
++ return 0;
++ }
++
+ value = 0;
+
+ if ( bits < 0 ) {
+@@ -203,6 +219,11 @@ int MSG_ReadBits( msg_t *msg, int bits ) {
+ }
+
+ if (msg->oob) {
++ if (msg->readcount + (bits>>3) > msg->cursize) {
++ msg->readcount = msg->cursize + 1;
++ return 0;
++ }
++
+ if(bits==8)
+ {
+ value = msg->data[msg->readcount];
+@@ -230,6 +251,10 @@ int MSG_ReadBits( msg_t *msg, int bits ) {
+ nbits = 0;
+ if (bits&7) {
+ nbits = bits&7;
++ if (msg->bit + nbits > msg->cursize << 3) {
++ msg->readcount = msg->cursize + 1;
++ return 0;
++ }
+ for(i=0;i<nbits;i++) {
+ value |= (Huff_getBit(msg->data, &msg->bit)<<i);
+ }
+@@ -238,9 +263,14 @@ int MSG_ReadBits( msg_t *msg, int bits ) {
+ if (bits) {
+ // fp = fopen("c:\\netchan.bin", "a");
+ for(i=0;i<bits;i+=8) {
+- Huff_offsetReceive (msgHuff.decompressor.tree, &get, msg->data, &msg->bit);
++ Huff_offsetReceive (msgHuff.decompressor.tree, &get, msg->data, &msg->bit, msg->cursize<<3);
+ // fwrite(&get, 1, 1, fp);
+ value |= (get<<(i+nbits));
++
++ if (msg->bit > msg->cursize<<3) {
++ msg->readcount = msg->cursize + 1;
++ return 0;
++ }
+ }
+ // fclose(fp);
+ }
+diff --git a/code/qcommon/qcommon.h b/code/qcommon/qcommon.h
+index d0cc9d6..6b86329 100644
+--- a/code/qcommon/qcommon.h
++++ b/code/qcommon/qcommon.h
+@@ -1179,9 +1179,9 @@ void Huff_Decompress(msg_t *buf, int offset);
+ void Huff_Init(huffman_t *huff);
+ void Huff_addRef(huff_t* huff, byte ch);
+ int Huff_Receive (node_t *node, int *ch, byte *fin);
+-void Huff_transmit (huff_t *huff, int ch, byte *fout);
+-void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset);
+-void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset);
++void Huff_transmit (huff_t *huff, int ch, byte *fout, int maxoffset);
++void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset, int maxoffset);
++void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset, int maxoffset);
+ void Huff_putBit( int bit, byte *fout, int *offset);
+ int Huff_getBit( byte *fout, int *offset);
+
diff -Nru ioquake3-1.36+u20140802+gca9eebb/debian/patches/series ioquake3-1.36+u20140802+gca9eebb/debian/patches/series
--- ioquake3-1.36+u20140802+gca9eebb/debian/patches/series 2017-03-14 18:29:48.000000000 -0400
+++ ioquake3-1.36+u20140802+gca9eebb/debian/patches/series 2017-08-12 10:15:49.000000000 -0400
@@ -6,3 +6,4 @@
security/Don-t-load-.pk3s-as-.dlls-and-don-t-load-user-config-file.patch
security/Don-t-open-.pk3-files-as-OpenAL-drivers.patch
security/Merge-some-file-writing-extension-checks-from-OpenJK.patch
+security/Fix-improve-buffer-overflow-in-MSG_ReadBits-MSG_WriteBits.patch
