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glx: Length checking for RenderLarge requests (v2) [CVE-2014-8098 3/8] 

This is a half-measure until we start passing request length into the
varsize function, but it's better than the nothing we had before.

v2: Verify that there's at least a large render header's worth of
dataBytes (Julien Cristau)

Reviewed-by: Michal Srb <msrb@suse.com>
Reviewed-by: Andy Ritger <aritger@nvidia.com>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
(cherry picked from commit a33a939e6a)
Signed-off-by: Julien Cristau <jcristau@debian.org>

Conflicts:
	glx/glxcmds.c
This commit is contained in:
Adam Jackson 2014-11-10 12:13:43 -05:00 committed by Julien Cristau
parent 7590915c9d
commit cbf197e1c9
1 changed files with 34 additions and 23 deletions
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57
glx/glxcmds.c
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@ -2107,6 +2107,8 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
__GLX_DECLARE_SWAP_VARIABLES;
REQUEST_AT_LEAST_SIZE(xGLXRenderLargeReq);
req = (xGLXRenderLargeReq *) pc;
if (client->swapped) {
__GLX_SWAP_SHORT(&req->length);
@ -2122,12 +2124,14 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
__glXResetLargeCommandStatus(cl);
return error;
}
if (safe_pad(req->dataBytes) < 0)
return BadLength;
dataBytes = req->dataBytes;
/*
** Check the request length.
*/
if ((req->length << 2) != __GLX_PAD(dataBytes) + sz_xGLXRenderLargeReq) {
if ((req->length << 2) != safe_pad(dataBytes) + sz_xGLXRenderLargeReq) {
client->errorValue = req->length;
/* Reset in case this isn't 1st request. */
__glXResetLargeCommandStatus(cl);
@ -2137,7 +2141,7 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
if (cl->largeCmdRequestsSoFar == 0) {
__GLXrenderSizeData entry;
int extra;
int extra = 0;
size_t cmdlen;
int err;
@ -2150,13 +2154,17 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
return __glXError(GLXBadLargeRequest);
}
if (dataBytes < __GLX_RENDER_LARGE_HDR_SIZE)
return BadLength;
hdr = (__GLXrenderLargeHeader *) pc;
if (client->swapped) {
__GLX_SWAP_INT(&hdr->length);
__GLX_SWAP_INT(&hdr->opcode);
}
cmdlen = hdr->length;
opcode = hdr->opcode;
if ((cmdlen = safe_pad(hdr->length)) < 0)
return BadLength;
/*
** Check for core opcodes and grab entry data.
@ -2178,17 +2186,13 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
if (extra < 0) {
return BadLength;
}
/* large command's header is 4 bytes longer, so add 4 */
if (cmdlen != __GLX_PAD(entry.bytes + 4 + extra)) {
return BadLength;
}
}
else {
/* constant size command */
if (cmdlen != __GLX_PAD(entry.bytes + 4)) {
return BadLength;
}
/* the +4 is safe because we know entry.bytes is small */
if (cmdlen != safe_pad(safe_add(entry.bytes + 4, extra))) {
return BadLength;
}
/*
** Make enough space in the buffer, then copy the entire request.
*/
@ -2215,6 +2219,7 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
** We are receiving subsequent (i.e. not the first) requests of a
** multi request command.
*/
int bytesSoFar; /* including this packet */
/*
** Check the request number and the total request count.
@ -2233,11 +2238,18 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
/*
** Check that we didn't get too much data.
*/
if ((cl->largeCmdBytesSoFar + dataBytes) > cl->largeCmdBytesTotal) {
if ((bytesSoFar = safe_add(cl->largeCmdBytesSoFar, dataBytes)) < 0) {
client->errorValue = dataBytes;
__glXResetLargeCommandStatus(cl);
return __glXError(GLXBadLargeRequest);
}
if (bytesSoFar > cl->largeCmdBytesTotal) {
client->errorValue = dataBytes;
__glXResetLargeCommandStatus(cl);
return __glXError(GLXBadLargeRequest);
}
memcpy(cl->largeCmdBuf + cl->largeCmdBytesSoFar, pc, dataBytes);
cl->largeCmdBytesSoFar += dataBytes;
cl->largeCmdRequestsSoFar++;
@ -2249,17 +2261,16 @@ __glXDisp_RenderLarge(__GLXclientState * cl, GLbyte * pc)
** This is the last request; it must have enough bytes to complete
** the command.
*/
/* NOTE: the two pad macros have been added below; they are needed
** because the client library pads the total byte count, but not
** the per-request byte counts. The Protocol Encoding says the
** total byte count should not be padded, so a proposal will be
** made to the ARB to relax the padding constraint on the total
** byte count, thus preserving backward compatibility. Meanwhile,
** the padding done below fixes a bug that did not allow
** large commands of odd sizes to be accepted by the server.
/* NOTE: the pad macro below is needed because the client library
** pads the total byte count, but not the per-request byte counts.
** The Protocol Encoding says the total byte count should not be
** padded, so a proposal will be made to the ARB to relax the
** padding constraint on the total byte count, thus preserving
** backward compatibility. Meanwhile, the padding done below
** fixes a bug that did not allow large commands of odd sizes to
** be accepted by the server.
*/
if (__GLX_PAD(cl->largeCmdBytesSoFar) !=
__GLX_PAD(cl->largeCmdBytesTotal)) {
if (safe_pad(cl->largeCmdBytesSoFar) != cl->largeCmdBytesTotal) {
client->errorValue = dataBytes;
__glXResetLargeCommandStatus(cl);
return __glXError(GLXBadLargeRequest);