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| author | Alan Coopersmith <alan.coopersmith@oracle.com> | 2013-04-12 21:44:59 -0700 |
|---|---|---|
| committer | Alan Coopersmith <alan.coopersmith@oracle.com> | 2013-05-04 21:44:31 -0700 |
| commit | 0e79d96c36aef5889ae2e2a3fc2e96e93f30dc21 (patch) | |
| tree | bc0a5a7d81ae6b7c82651e5d3046164ba6a0d457 | |
| parent | 1c7ad6773ce6be00dcd6e51e9be08f203abe5071 (diff) | |
| download | xorg-lib-libXrandr-0e79d96c36aef5889ae2e2a3fc2e96e93f30dc21.tar.gz | |
integer overflow in XRRQueryOutputProperty() [CVE-2013-1986 1/4]
rep.length is a CARD32, while rbytes was a signed int, so
rbytes = sizeof (XRRPropertyInfo) + rep.length * sizeof (long);
could result in integer overflow, leading to an undersized malloc
and reading data off the connection and writing it past the end of
the allocated buffer.
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
| -rw-r--r-- | src/XrrProperty.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/src/XrrProperty.c b/src/XrrProperty.c index 2b065b2..50382bf 100644 --- a/src/XrrProperty.c +++ b/src/XrrProperty.c @@ -31,6 +31,7 @@ #include <X11/extensions/render.h> #include <X11/extensions/Xrender.h> #include "Xrandrint.h" +#include <limits.h> Atom * XRRListOutputProperties (Display *dpy, RROutput output, int *nprop) @@ -84,7 +85,7 @@ XRRQueryOutputProperty (Display *dpy, RROutput output, Atom property) XExtDisplayInfo *info = XRRFindDisplay(dpy); xRRQueryOutputPropertyReply rep; xRRQueryOutputPropertyReq *req; - int rbytes, nbytes; + unsigned int rbytes, nbytes; XRRPropertyInfo *prop_info; RRCheckExtension (dpy, info, NULL); @@ -102,10 +103,14 @@ XRRQueryOutputProperty (Display *dpy, RROutput output, Atom property) return NULL; } - rbytes = sizeof (XRRPropertyInfo) + rep.length * sizeof (long); - nbytes = rep.length << 2; + if (rep.length < ((INT_MAX / sizeof(long)) - sizeof (XRRPropertyInfo))) { + rbytes = sizeof (XRRPropertyInfo) + (rep.length * sizeof (long)); + nbytes = rep.length << 2; + + prop_info = Xmalloc (rbytes); + } else + prop_info = NULL; - prop_info = (XRRPropertyInfo *) Xmalloc (rbytes); if (prop_info == NULL) { _XEatDataWords(dpy, rep.length); UnlockDisplay (dpy); |