heap-based buffer overflow write in read_1g (stream.c)

[asarubbo]

On 0.631:

# lrzip -t $FILE
Decompressing...
=================================================================
==25584==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60200000ef33 at pc 0x00000045246e bp 0x7ffd881d4970 sp 0x7ffd881d4120
WRITE of size 8 at 0x60200000ef33 thread T0
    #0 0x45246d in read /tmp/portage/sys-devel/llvm-3.9.1-r1/work/llvm-3.9.1.src/projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:765
    #1 0x537ce1 in read_1g /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:731:9
    #2 0x53e349 in read_buf /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:774:8
    #3 0x53e349 in fill_buffer /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:1648
    #4 0x53e349 in read_stream /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:1755
    #5 0x5307fc in read_vchars /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:79:6
    #6 0x5307fc in unzip_match /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:208
    #7 0x5307fc in runzip_chunk /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:329
    #8 0x5307fc in runzip_fd /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:382
    #9 0x519b41 in decompress_file /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/lrzip.c:826:6
    #10 0x511074 in main /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/main.c:669:4
    #11 0x7f02ed48f78f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
    #12 0x41abf8 in _init (/usr/bin/lrzip+0x41abf8)

0x60200000ef33 is located 0 bytes to the right of 3-byte region [0x60200000ef30,0x60200000ef33)
allocated by thread T0 here:
    #0 0x4d39b8 in malloc /tmp/portage/sys-devel/llvm-3.9.1-r1/work/llvm-3.9.1.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:64
    #1 0x53e2ab in fill_buffer /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:1643:10
    #2 0x53e2ab in read_stream /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/stream.c:1755
    #3 0x5307fc in read_vchars /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:79:6
    #4 0x5307fc in unzip_match /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:208
    #5 0x5307fc in runzip_chunk /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:329
    #6 0x5307fc in runzip_fd /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/runzip.c:382
    #7 0x519b41 in decompress_file /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/lrzip.c:826:6
    #8 0x511074 in main /tmp/portage/app-arch/lrzip-0.631/work/lrzip-0.631/main.c:669:4
    #9 0x7f02ed48f78f in __libc_start_main /tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289

SUMMARY: AddressSanitizer: heap-buffer-overflow /tmp/portage/sys-devel/llvm-3.9.1-r1/work/llvm-3.9.1.src/projects/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:765 in read
Shadow bytes around the buggy address:
  0x0c047fff9d90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9de0: fa fa fa fa fa fa[03]fa fa fa fd fd fa fa fd fa
  0x0c047fff9df0: fa fa fd fd fa fa 04 fa fa fa 03 fa fa fa 05 fa
  0x0c047fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e30: 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
==25584==ABORTING

Reproducer:
https://github.com/asarubbo/poc/blob/master/00232-lrzip-heapoverflow-read_1g

[ppisar]

CVE-2017-8844 was assigned http://seclists.org/oss-sec/2017/q2/234.

[pete4abw]

Peter. Maybe just submit a patch instead of so many posts. Or just make one past.

…

On May 9, 2017 8:38:22 AM CDT, Petr Pisar ***@***.***> wrote: CVE-2017-8844 was assigned http://seclists.org/oss-sec/2017/q2/234. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #70 (comment)

-- Peter Hyman +1(609)598-0262 Sent from mobile. Sorry for any typos.

[ariccio]

In fill_buffer, I noticed this:

padded_len = MAX(c_len, MIN_SIZE);

then

s_buf = malloc(MAX(u_len, MIN_SIZE));

and then

if (unlikely(read_buf(control, sinfo->fd, s_buf, padded_len)))

Hmm. Suspicious?

[ckolivas]

Yes that's correct, thanks. Finally attended to.