GNU binutils - 'aarch64_ext_ldst_reglist' Buffer Overflow

Source: https://sourceware.org/bugzilla/show_bug.cgi?id=21595

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 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`.

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

--

Input: 3ade4a4333249762a9df82c47f3c111a.65dbcbffa0f6467be847e1372688623b.min
Output: 3ade4a4333249762a9df82c47f3c111a.65dbcbffa0f6467be847e1372688623b.txt

Error in "aarch64_ext_ldst_reglist": global-buffer-overflow
  in aarch64_ext_ldst_reglist at opcodes/aarch64-dis.c:412
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/aarch64-dis.c#L412)
  in aarch64_opcode_decode at opcodes/aarch64-dis.c:2739
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/aarch64-dis.c#L2739)
  in aarch64_decode_insn at opcodes/aarch64-dis.c:2831
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/aarch64-dis.c#L2831)
  in print_insn_aarch64_word at opcodes/aarch64-dis.c:2973
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/aarch64-dis.c#L2973)
  in print_insn_aarch64 at opcodes/aarch64-dis.c:3209
    (see https://github.com/bminor/binutils-gdb/blob/561bf3e950e410fbcac06523d43039f1f58150ca/opcodes/aarch64-dis.c#L3209)
  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)


Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42204.zip