From 1559a94395258fd73e369f1a2c98a44bfe21a486 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Tue, 9 Dec 2014 09:31:00 -0800 Subject: [PATCH 2/2] dix: GetHosts bounds check using wrong pointer value [CVE-2014-8092 pt. 6] GetHosts saves the pointer to allocated memory in *data, and then wants to bounds-check writes to that region, but was mistakenly using a bare 'data' instead of '*data'. Also, data is declared as void **, so we need a cast to turn it into a byte pointer so we can actually do pointer comparisons. Signed-off-by: Keith Packard Reviewed-by: Alan Coopersmith Signed-off-by: Alan Coopersmith --- os/access.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/os/access.c b/os/access.c index f393c8d..28f2d32 100644 --- a/os/access.c +++ b/os/access.c @@ -1308,7 +1308,7 @@ GetHosts(void **data, int *pnHosts, int *pLen, BOOL * pEnabled) } for (host = validhosts; host; host = host->next) { len = host->len; - if ((ptr + sizeof(xHostEntry) + len) > (data + n)) + if ((ptr + sizeof(xHostEntry) + len) > ((unsigned char *) *data + n)) break; ((xHostEntry *) ptr)->family = host->family; ((xHostEntry *) ptr)->length = len; -- 2.1.0