AddressSanitizer: stack-buffer-overflow at libr/asm/arch/arm/armass64.c:740

[hongxuchen]

Work environment

Questions	Answers
OS/arch/bits (mandatory)	Ubuntu x86 64
File format of the file you reverse (mandatory)	-
Architecture/bits of the file (mandatory)	-
r2 -v full output, not truncated (mandatory)	rasm2 3.1.0 20265 @ linux-x86-64 git.3.1.0-46-g23a0cfcdd commit: 23a0cfc build: 2018-12-02__22:59:40

Expected behavior

rasm2 exits with error messages

Actual behavior

rasm2 crashes

==12719==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffcb1a49150 at pc 0x7fd749638618 bp 0x7ffcb1a49050 sp 0x7ffcb1a49048
WRITE of size 4 at 0x7ffcb1a49150 thread T0
    #0 0x7fd749638617 in parseOperands /home/exp/FOT/radare2-fuzz/libr/asm/p/../arch/arm/armass64.c:740:30
    #1 0x7fd749638617 in parseOpcode /home/exp/FOT/radare2-fuzz/libr/asm/p/../arch/arm/armass64.c:867
    #2 0x7fd749638617 in arm64ass /home/exp/FOT/radare2-fuzz/libr/asm/p/../arch/arm/armass64.c:872
    #3 0x7fd74956725d in assemble /home/exp/FOT/radare2-fuzz/libr/asm/p/asm_arm_cs.c:136:8
    #4 0x7fd749995f25 in r_asm_assemble /home/exp/FOT/radare2-fuzz/libr/asm/asm.c:594:10
    #5 0x7fd74999a986 in r_asm_massemble /home/exp/FOT/radare2-fuzz/libr/asm/asm.c:980:12
    #6 0x7fd7499a13ff in r_asm_rasm_assemble /home/exp/FOT/radare2-fuzz/libr/asm/asm.c:1137:10
    #7 0x56453eb71cfe in rasm_asm /home/exp/FOT/radare2-fuzz/binr/rasm2/rasm2.c:370:16
    #8 0x56453eb71b1e in print_assembly_output /home/exp/FOT/radare2-fuzz/binr/rasm2/rasm2.c:429:8
    #9 0x56453eb6ebd3 in main /home/exp/FOT/radare2-fuzz/binr/rasm2/rasm2.c:804:10
    #10 0x7fd746621b96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
    #11 0x56453ea72af9 in _start (/home/exp/FOT/radare2-fuzz/binr/rasm2/rasm2+0x1eaf9)

Address 0x7ffcb1a49150 is located in stack of thread T0 at offset 240 in frame
    #0 0x7fd74962e87f in arm64ass /home/exp/FOT/radare2-fuzz/libr/asm/p/../arch/arm/armass64.c:870

  This frame has 1 object(s):
    [32, 240) 'ops' (line 871) <== Memory access at offset 240 overflows this variable
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/exp/FOT/radare2-fuzz/libr/asm/p/../arch/arm/armass64.c:740:30 in parseOperands
Shadow bytes around the buggy address:
  0x1000163411d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000163411e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1000163411f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100016341200: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
  0x100016341210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x100016341220: 00 00 00 00 00 00 00 00 00 00[f3]f3 f3 f3 f3 f3
  0x100016341230: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
  0x100016341240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100016341250: 00 00 00 00 f1 f1 f1 f1 04 f2 f8 f3 00 00 00 00
  0x100016341260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100016341270: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
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
==12719==ABORTING
[1]    12719 abort      rasm2 -a arm -b 64 '0 ,0,0,0,0,0,0,'

Steps to reproduce the behavior

• run rasm2 -a arm -b 64 '0 ,0,0,0,0,0,0,'

Additional Logs, screenshots, source-code, configuration dump, ...

We also find another file generates from r2's pd $s results that also emits such an error when running rasm2 -a arm -b 64 -f $FILE.

[hongxuchen]

The crash happens when radare2 is compiled with Clang -fsanitize=address -g -O3.