[Nasm-bugs] [Bug 3392504] New: ndisasm (nasm-2.14rc15) - Stack Buffer Overflow

[noreply-nasm at gorcunov.org]

https://bugzilla.nasm.us/show_bug.cgi?id=3392504

            Bug ID: 3392504
           Summary: ndisasm (nasm-2.14rc15) - Stack Buffer Overflow
           Product: NASM
           Version: unspecified
          Hardware: All
                OS: All
            Status: OPEN
          Severity: normal
          Priority: Medium
         Component: Disassembler
          Assignee: nobody at nasm.us
          Reporter: nafiez.skins at gmail.com
                CC: gorcunov at gmail.com, hpa at zytor.com, nasm-bugs at nasm.us
     Obtained from: Build from source archive using configure

Created attachment 411659
  --> https://bugzilla.nasm.us/attachment.cgi?id=411659&action=edit
POC generated by AFL

An buffer overflow trigger upon fuzzing. We compiled the program with ASAN to
see the result crash. Target version of ndisasm (nasm-2.14rc15). 

==31549==ERROR: AddressSanitizer: stack-buffer-overflow on address
0x7ffc2dc6ad80 at pc 0x000000523f5a bp 0x7ffc2dc6a4d0 sp 0x7ffc2dc6a4c8
READ of size 1 at 0x7ffc2dc6ad80 thread T0
    #0 0x523f59  (/home/john/fuzzing/nasm-2.14rc15/ndisasm+0x523f59)
    #1 0x50dd2a  (/home/john/fuzzing/nasm-2.14rc15/ndisasm+0x50dd2a)
    #2 0x7f84e2c6bb96  (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #3 0x41c5e9  (/home/john/fuzzing/nasm-2.14rc15/ndisasm+0x41c5e9)

Address 0x7ffc2dc6ad80 is located in stack of thread T0 at offset 416 in frame
    #0 0x50babf  (/home/john/fuzzing/nasm-2.14rc15/ndisasm+0x50babf)

  This frame has 7 object(s):
    [32, 288) 'buffer.i'
    [352, 416) 'buffer' <== Memory access at offset 416 overflows this variable
    [448, 456) 'ep'
    [480, 736) 'outbuf'
    [800, 804) 'synclen'
    [816, 832) 'prefer'
    [848, 849) 'rn_error'
HINT: this may be a false positive if your program uses some custom stack
unwind mechanism or swapcontext
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow
(/home/john/fuzzing/nasm-2.14rc15/ndisasm+0x523f59) 
Shadow bytes around the buggy address:
  0x100005b85560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100005b85570: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
  0x100005b85580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100005b85590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100005b855a0: f2 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00
=>0x100005b855b0:[f2]f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00 00 00
  0x100005b855c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100005b855d0: 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2 f2 f2
  0x100005b855e0: 04 f2 00 00 f2 f2 01 f3 00 00 00 00 00 00 00 00
  0x100005b855f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100005b85600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  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
==31549==ABORTING

-- 
You are receiving this mail because:
You are watching all bug changes.
You are on the CC list for the bug.