From b20912c3d45cbbde3c443e6c3d9e189092fe65e1 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Tue, 9 Dec 2014 09:30:57 -0800 Subject: [PATCH] dbe: Call to DDX SwapBuffers requires address of int, not unsigned int [CVE-2014-8097 pt. 2] When the local types used to walk the DBE request were changed, this changed the type of the parameter passed to the DDX SwapBuffers API, but there wasn't a matching change in the API definition. At this point, with the API frozen, I just stuck a new variable in with the correct type. Because we've already bounds-checked nStuff to be smaller than UINT32_MAX / sizeof(DbeSwapInfoRec), we know it will fit in a signed int without overflow. Signed-off-by: Keith Packard Signed-off-by: Alan Coopersmith --- dbe/dbe.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/dbe/dbe.c b/dbe/dbe.c index df2ad5c51..e5d928d7b 100644 --- a/dbe/dbe.c +++ b/dbe/dbe.c @@ -452,6 +452,7 @@ ProcDbeSwapBuffers(ClientPtr client) int error; unsigned int i, j; unsigned int nStuff; + int nStuff_i; /* DDX API requires int for nStuff */ REQUEST_AT_LEAST_SIZE(xDbeSwapBuffersReq); nStuff = stuff->n; /* use local variable for performance. */ @@ -527,9 +528,10 @@ ProcDbeSwapBuffers(ClientPtr client) * could deal with cross-screen synchronization. */ - while (nStuff > 0) { + nStuff_i = nStuff; + while (nStuff_i > 0) { pDbeScreenPriv = DBE_SCREEN_PRIV_FROM_WINDOW(swapInfo[0].pWindow); - error = (*pDbeScreenPriv->SwapBuffers) (client, &nStuff, swapInfo); + error = (*pDbeScreenPriv->SwapBuffers) (client, &nStuff_i, swapInfo); if (error != Success) { free(swapInfo); return error;