Date: Thu, 01 Aug 2002 12:33:27 +0200 From: Rolf Grossmann <rg@progtech.net> To: freebsd-security@FreeBSD.ORG Subject: Re: FreeBSD Security Advisory FreeBSD-SA-02:34.rpc Message-ID: <3D490E77.6050003@PROGTECH.net> References: <200208010246.g712k6NM003336@freefall.freebsd.org>
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Hi,
I've been looking at your patch for the rpc buffer overflow and I
believe it's not sufficient.
You're using:
if ((c > maxsize && UINT_MAX/elsize < c) &&
(xdrs->x_op != XDR_FREE)) {
return (FALSE);
but I think it really should test both conditions (the braces suggest that you
actually meant that anyway):
if ((c > maxsize || UINT_MAX/elsize < c) &&
(xdrs->x_op != XDR_FREE)) {
return (FALSE);
Otherwise, if the writer of the application using xdr_array specified
maxsize too large (maybe he didn't care), you're in trouble again. I think
it's clearer if you write the condition the other way round:
if ((c > maxsize || c > UINT_MAX/elsize) &&
(xdrs->x_op != XDR_FREE)) {
return (FALSE);
Should I file a PR or am I completely off track here?
Bye, Rolf
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