Bug 21062

Summary:	SIGSEGV when mmap() fails
Product:	fontconfig	Reporter:	Serge van den Boom <svdb+freedesktop.org>
Component:	library	Assignee:	Keith Packard <keithp>
Status:	RESOLVED FIXED	QA Contact:	Behdad Esfahbod <freedesktop>
Severity:	normal
Priority:	medium	CC:	freedesktop
Version:	2.6	Keywords:	patch
Hardware:	All
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	Fix

Description Serge van den Boom 2009-04-05 09:57:32 UTC

Created attachment 24582 [details] [review]
Fix

In fccache.c, there is the line
    cache = mmap (0, fd_stat->st_size, PROT_READ, MAP_SHARED, fd, 0);
Furtheron there is the check
    if (!cache)
But mmap() returns MAP_FAILED on failure, which is (void *) -1, and not NULL. So if mmap() fails, the guard of that if-statement will evaluate to false, and no cache is allocated, resulting in a crash a few lines later at
    if (cache->magic != FC_CACHE_MAGIC_MMAP

Comment 1 Behdad Esfahbod 2009-04-05 16:00:53 UTC

Oops.  Thanks for the patch.  In my tree now.

Comment 2 Behdad Esfahbod 2009-06-24 12:36:02 UTC

I believe I've fixed this in 2.7.0.  Please reopen otherwise.

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