ytnef: memory allocation failure in TNEFFillMapi (ytnef.c)

["Agostino Sarubbo" <ago () gentoo org>]

Description:
ytnef is Yeraze’s TNEF Stream Reader – for winmail.dat files.

The complete ASan output of the issue:

# ytnefprint $FILE
==11998==AddressSanitizer CHECK failed: 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/sanitizer_common/sanitizer_common.cc:120
 "((0 && "unable to mmap")) != (0)" (0x0, 0x0)
    #0 0x4d95cf in __asan::AsanCheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_rtl.cc:69
    #1 0x4f4335 in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/sanitizer_common/sanitizer_termination.cc:79
    #2 0x4e3962 in __sanitizer::ReportMmapFailureAndDie(unsigned long, char const*, char const*, int, bool) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/sanitizer_common/sanitizer_common.cc:120
    #3 0x4ed265 in __sanitizer::MmapOrDie(unsigned long, char const*, bool) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/sanitizer_common/sanitizer_posix.cc:132
    #4 0x424c6a in __sanitizer::LargeMmapAllocator::Allocate(__sanitizer::AllocatorStats*, unsigned long, unsigned 
long) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_allocator_secondary.h:41
    #5 0x424c6a in __sanitizer::CombinedAllocator<__sanitizer::SizeClassAllocator64, 
__sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator64 >, __sanitizer::LargeMmapAllocator 
> ::Allocate(__sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator64 >*, unsigned long, unsigned 
long, bool, bool) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/../sanitizer_common/sanitizer_allocator_combined.h:70
    #6 0x424c6a in __asan::Allocator::Allocate(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*, 
__asan::AllocType, bool) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_allocator.cc:407
    #7 0x41f1fb in __asan::Allocator::Calloc(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_allocator.cc:605
    #8 0x41f1fb in __asan::asan_calloc(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*) 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_allocator.cc:786
    #9 0x4cf7ba in calloc 
/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.0/work/compiler-rt-4.0.0.src/lib/asan/asan_malloc_linux.cc:75
    #10 0x7fe45c3e4e53 in TNEFFillMapi /tmp/ytnef-1.9.2/lib/ytnef.c:424:19
    #11 0x7fe45c3e1384 in TNEFMapiProperties /tmp/ytnef-1.9.2/lib/ytnef.c:396:7
    #12 0x7fe45c3f6b47 in TNEFParse /tmp/ytnef-1.9.2/lib/ytnef.c:1184:15
    #13 0x7fe45c3f59d3 in TNEFParseFile /tmp/ytnef-1.9.2/lib/ytnef.c:1042:10
    #14 0x508814 in main /tmp/ytnef-1.9.2/ytnefprint/main.c:80:9
    #15 0x7fe45b50b78f in __libc_start_main 
/tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
    #16 0x419c38 in _start (/usr/bin/ytnefprint+0x419c38)

Affected version:
1.9.2

Fixed version:
N/A

Commit fix:
N/A

Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.

CVE:
CVE-2017-9473

Reproducer:
https://github.com/asarubbo/poc/blob/master/00246-ytnef-memallocfailures

Timeline:
2017-03-27: bug discovered and reported to upstream
2017-05-24: blog post about the issue
2017-06-07: CVE assigned

Note:
This bug was found with American Fuzzy Lop.

Permalink:
https://blogs.gentoo.org/ago/2017/05/24/ytnef-memory-allocation-failure-in-tneffillmapi-ytnef-c/

--
Agostino Sarubbo
Gentoo Linux Developer