Bug 21587 - global-buffer-overflow in rx_decode_opcode
Summary: global-buffer-overflow in rx_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 21:03 UTC by Alexandre Adamski
Modified: 2017-06-14 12:38 UTC (History)
1 user (show)

See Also:
Last reconfirmed:

testcase (59 bytes, application/octet-stream)
2017-06-13 21:03 UTC, Alexandre Adamski
report (1013 bytes, text/plain)
2017-06-13 21:03 UTC, Alexandre Adamski

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Description Alexandre Adamski 2017-06-13 21:03:08 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: 9ed130cf25d8df5207cad7fc0de4fc1f.109246746a4907b00292c7837b29f085.min
Output: 9ed130cf25d8df5207cad7fc0de4fc1f.109246746a4907b00292c7837b29f085.txt

Error in "rx_decode_opcode": global-buffer-overflow
  in rx_decode_opcode at opcodes/rx-decode.opc:288
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/rx-decode.opc#L288)
  in print_insn_rx at opcodes/rx-dis.c:123
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/rx-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 21:03:25 UTC
Created attachment 10120 [details]
Comment 2 Alexandre Adamski 2017-06-13 21:03:38 UTC
Created attachment 10121 [details]
Comment 3 Alexandre Adamski 2017-06-13 22:35:48 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 2017-06-14 12:36:25 UTC
The master branch has been updated by Nick Clifton <nickc@sourceware.org>:


commit db5fa770268baf8cc82cf9b141d69799fd485fe2
Author: Nick Clifton <nickc@redhat.com>
Date:   Wed Jun 14 13:35:06 2017 +0100

    Fix address violation problems when disassembling a corrupt RX binary.
    	PR binutils/21587
    	* rx-decode.opc: Include libiberty.h
    	(GET_SCALE): New macro - validates access to SCALE array.
    	(GET_PSCALE): New macro - validates access to PSCALE array.
    	(DIs, SIs, S2Is, rx_disp): Use new macros.
    	* rx-decode.c: Regenerate.
Comment 5 Nick Clifton 2017-06-14 12:38:57 UTC
Hi Aadamski,

  Thanks for reporting this problem.

  I have checked in a patch to add some more checks to the RX disassembler.