From 6e1b743a276651195be3cd68dff41e38426bf3ab Mon Sep 17 00:00:00 2001 From: Alan Coopersmith Date: Sat, 13 Apr 2013 00:03:03 -0700 Subject: [PATCH 2/5] integer overflow in XvQueryPortAttributes() [CVE-2013-1989 1/3] The num_attributes & text_size members of the reply are both CARD32s and need to be bounds checked before multiplying & adding them together to come up with the total size to allocate, to avoid integer overflow leading to underallocation and writing data from the network past the end of the allocated buffer. Reported-by: Ilja Van Sprundel Signed-off-by: Alan Coopersmith --- src/Xv.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/src/Xv.c b/src/Xv.c index 5be1d95..3cbad35 100644 --- a/src/Xv.c +++ b/src/Xv.c @@ -851,9 +851,15 @@ XvQueryPortAttributes(Display *dpy, XvPortID port, int *num) } if(rep.num_attributes) { - int size = (rep.num_attributes * sizeof(XvAttribute)) + rep.text_size; + unsigned long size; + /* limit each part to no more than one half the max size */ + if ((rep.num_attributes < ((INT_MAX / 2) / sizeof(XvAttribute))) && + (rep.text_size < (INT_MAX / 2))) { + size = (rep.num_attributes * sizeof(XvAttribute)) + rep.text_size; + ret = Xmalloc(size); + } - if((ret = Xmalloc(size))) { + if (ret != NULL) { char* marker = (char*)(&ret[rep.num_attributes]); xvAttributeInfo Info; int i; -- 1.8.2.3