Bug 21588 - stack-buffer-overflow in rl78_decode_opcode
Summary: stack-buffer-overflow in rl78_decode_opcode
Alias: None
Product: binutils
Classification: Unclassified
Component: binutils (show other bugs)
Version: 2.29
: P2 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
Depends on:
Reported: 2017-06-13 21:04 UTC by Alexandre Adamski
Modified: 2017-06-15 11:41 UTC (History)
1 user (show)

See Also:
Last reconfirmed:

testcase (63 bytes, application/octet-stream)
2017-06-13 21:04 UTC, Alexandre Adamski
report (1.08 KB, text/plain)
2017-06-13 21:05 UTC, Alexandre Adamski

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Description Alexandre Adamski 2017-06-13 21:04:29 UTC
Hello there,

I have been fuzzing objdump with American Fuzzy Lop and AddressSanitizer.

Please find attached the minimized file causing the issue ("Input") and the
ASAN report log ("Output"). Below is the reduced stacktrace with links to the
corresponding source lines on a GitHub mirror.

The command I used was `objdump -D <file>`.

Let me know if there is any additional information I can provide.


Input: 03ee135139d8cc43f9282e5a5d68a019.02b2e509a71e4909a73a734d69f2f503.min
Output: 03ee135139d8cc43f9282e5a5d68a019.02b2e509a71e4909a73a734d69f2f503.txt

Error in "rl78_decode_opcode": stack-buffer-overflow
  in rl78_decode_opcode at opcodes/rl78-decode.opc:190
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/rl78-decode.opc#L190)
  in print_insn_rl78_common at opcodes/rl78-dis.c:123
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/rl78-dis.c#L123)
  in disassemble_bytes at binutils/objdump.c:1864
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L1864)
  in disassemble_section at binutils/objdump.c:2309
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L2309)
  in bfd_map_over_sections at bfd/section.c:1395
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/bfd/section.c#L1395)
  in disassemble_data at binutils/objdump.c:2445
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L2445)
  in dump_bfd at binutils/objdump.c:3547
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L3547)
  in display_file at binutils/objdump.c:3714
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L3714)
  in main at binutils/objdump.c:4016
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/binutils/objdump.c#L4016)
Comment 1 Alexandre Adamski 2017-06-13 21:04:47 UTC
Created attachment 10122 [details]
Comment 2 Alexandre Adamski 2017-06-13 21:05:01 UTC
Created attachment 10123 [details]
Comment 3 Alexandre Adamski 2017-06-13 22:41:27 UTC
Additional Information:
The command used was `objdump -D <file>`. The compilation flags used were `-g -O2 -fno-omit-frame-pointer -fsanitize=address -fno-sanitize-recover=undefined`. The configuration settings used were `--enable-targets=all --disable-shared`.
Comment 4 Sourceware Commits 2017-06-15 11:37:59 UTC
The master branch has been updated by Nick Clifton <nickc@sourceware.org>:


commit 63323b5b23bd83fa7b04ea00dff593c933e9b0e3
Author: Nick Clifton <nickc@redhat.com>
Date:   Thu Jun 15 12:37:01 2017 +0100

    Fix address violation when disassembling a corrupt RL78 binary.
    	PR binutils/21588
    	* rl78-decode.opc (OP_BUF_LEN): Define.
    	(GETBYTE): Check for the index exceeding OP_BUF_LEN.
    	(rl78_decode_opcode): Use OP_BUF_LEN as the length of the op_buf
    	* rl78-decode.c: Regenerate.
Comment 5 Nick Clifton 2017-06-15 11:41:30 UTC
Hi Aadamski,

  Thanks for reporting this bug.

  The problem this time was an overrun of the buffer used to contain RL78 
  opcodes.  I have added a simple overflow check, so the problem should now
  be resolved.