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Re: [Xen-devel] [PATCH] libxc hardening

To: Anthony Liguori <aliguori@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] libxc hardening
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Thu, 23 Jun 2005 09:43:50 +0100
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On 23 Jun 2005, at 05:15, Anthony Liguori wrote:

The following patches hardens a good portion of libxc's error path code against errno clobbering. Errno clobbering occurs when a function returns a failure code (such as -1) but then calls some other function (like munmap or perror) that could potentially change the value of errno.

mmap() will never return NULL address (according to the man page). I guess you might be able to force it with MAP_FIXED, but no sane mmap implementation would ever automatically choose NULL as a reasonable valid return address. :-)

 -- Keir

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