Description:
elfutils is a set of libraries/utilities to handle ELF objects (drop in replacement for libelf).
A fuzz on eu-elflint showed an heap overflow.
The complete ASan output:
# eu-elflint -d $FILE ==14428==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60b00000aff4 at pc 0x00000040b36b bp 0x7ffe1e25ef20 sp 0x7ffe1e25ef18 READ of size 4 at 0x60b00000aff4 thread T0 #0 0x40b36a in check_sysv_hash /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:2020 #1 0x40b36a in check_hash /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:2315 #2 0x422e73 in check_sections /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4118 #3 0x42961f in process_elf_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4697 #4 0x42961f in process_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:242 #5 0x402d33 in main /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:175 #6 0x7f7a318a878f in __libc_start_main (/lib64/libc.so.6+0x2078f) #7 0x403498 in _start (/usr/bin/eu-elflint+0x403498) 0x60b00000aff7 is located 0 bytes to the right of 103-byte region [0x60b00000af90,0x60b00000aff7) allocated by thread T0 here: #0 0x7f7a32f95288 in malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/libasan.so.3+0xc2288) #1 0x7f7a32bf1b46 in convert_data /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:166 #2 0x7f7a32bf1b46 in __libelf_set_data_list_rdlock /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:434 #3 0x7f7a32bf2662 in __elf_getdata_rdlock /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:541 #4 0x7f7a32bf2776 in elf_getdata /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf_getdata.c:559 #5 0x7f7a32c1e035 in elf32_getchdr /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/elf32_getchdr.c:72 #6 0x7f7a32c1e55c in gelf_getchdr /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/libelf/gelf_getchdr.c:52 #7 0x420edf in check_sections /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:3911 #8 0x42961f in process_elf_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:4697 #9 0x42961f in process_file /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:242 #10 0x402d33 in main /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:175 #11 0x7f7a318a878f in __libc_start_main (/lib64/libc.so.6+0x2078f) SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/dev-libs/elfutils-0.168/work/elfutils-0.168/src/elflint.c:2020 in check_sysv_hash Shadow bytes around the buggy address: 0x0c167fff95a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff95b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff95c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff95d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff95e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa =>0x0c167fff95f0: fa fa 00 00 00 00 00 00 00 00 00 00 00 00[07]fa 0x0c167fff9600: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff9610: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff9620: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff9630: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x0c167fff9640: 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 ==14428==ABORTING
Affected version:
0.168
Fixed version:
0.169 (not released atm)
Commit fix:
https://sourceware.org/ml/elfutils-devel/2017-q1/msg00131.html
Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.
CVE:
CVE-2017-7612
Reproducer:
https://github.com/asarubbo/poc/blob/master/00235-elfutils-heapoverflow-check_sysv_hash
Timeline:
2017-03-27: bug discovered and reported to upstream
2017-04-04: blog post about the issue
2017-04-09: CVE assigned
Note:
This bug was found with American Fuzzy Lop.
Permalink:
elfutils: heap-based buffer overflow in check_sysv_hash (elflint.c)