Description:
libdwarf is a library to consume and produce DWARF debug information.
A fuzz on an updated version revealed a buffer overflow.
The complete ASan output:
# dwarfdump $FILE
==27460==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60600000eff4 at pc 0x00000047349b bp 0x7ffd9feadaf0 sp 0x7ffd9fead2a0
READ of size 2 at 0x60600000eff4 thread T0
#0 0x47349a in memcpy /var/tmp/portage/sys-devel/llvm-3.8.1-r2/work/llvm-3.8.1.src/projects/compiler-rt/lib/asan/asan_interceptors.cc:438
#1 0x56cbe0 in dwarf_get_aranges_list /tmp/dwarf-20161021/libdwarf/dwarf_arange.c:118:9
#2 0x56c0dc in dwarf_get_aranges /tmp/dwarf-20161021/libdwarf/dwarf_arange.c:318:11
#3 0x50f103 in print_aranges /tmp/dwarf-20161021/dwarfdump/print_aranges.c:145:12
#4 0x4fb2bf in process_one_file /tmp/dwarf-20161021/dwarfdump/dwarfdump.c:1420:9
#5 0x4fb2bf in main /tmp/dwarf-20161021/dwarfdump/dwarfdump.c:654
#6 0x7f2b42a4461f in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289
#7 0x419588 in _start (/usr/bin/dwarfdump-asan+0x419588)
0x60600000eff4 is located 0 bytes to the right of 52-byte region [0x60600000efc0,0x60600000eff4)
allocated by thread T0 here:
#0 0x4c0ad8 in malloc /var/tmp/portage/sys-devel/llvm-3.8.1-r2/work/llvm-3.8.1.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:52
#1 0x7f2b43b1e206 in __libelf_set_rawdata_wrlock /tmp/portage/dev-libs/elfutils-0.166/work/elfutils-0.166/libelf/elf_getdata.c:318
SUMMARY: AddressSanitizer: heap-buffer-overflow
/var/tmp/portage/sys-devel/llvm-3.8.1-r2/work/llvm-3.8.1.src/projects/compiler-rt/lib/asan/asan_interceptors.cc:438 in memcpy
Shadow bytes around the buggy address:
0x0c0c7fff9da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9de0: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00
=>0x0c0c7fff9df0: 00 00 00 00 fa fa fa fa 00 00 00 00 00 00[04]fa
0x0c0c7fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9e20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9e30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fff9e40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==27460==ABORTING
Affected version:
20161021
Fixed version:
20161124
Commit fix:
https://sourceforge.net/p/libdwarf/code/ci/583f8834083b5ef834c497f5b47797e16101a9a6/
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2016-9276
Reproducer:
https://github.com/asarubbo/poc/blob/master/00026-libdwarf-heapoverflow-dwarf_get_aranges_list
Timeline:
2016-11-02: bug discovered and reported to upstream
2016-11-05: upstream released a patch
2016-11-07: blog post about the issue
2016-11-11: CVE assigned
2016-11-24: upstream released 20161124
Note:
This bug was found with American Fuzzy Lop.
Permalink:
libdwarf: heap-based buffer overflow in dwarf_get_aranges_list (dwarf_arange.c)