[Bug sanitizer/107410] New: ASan failed to detect a heap-buffer-overflow

[shaohua.li at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107410

            Bug ID: 107410
           Summary: ASan failed to detect a  heap-buffer-overflow
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: shaohua.li at inf dot ethz.ch
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org
  Target Milestone: ---

For the following code, `gcc-fsanitize=address -O0` reported nothing, while
`gcc -fsanitize=address -Ox` (x=1, 2, 3, or s) reported the
heap-buffer-overflow. There is a stack-buffer-overflow in `c[i] = 2`, which has
crossed the red-zone but I believe it should not affect the
heap-buffer-overflow detection.

% gcc-tk -tv
Using built-in specs.
COLLECT_GCC=gcc-tk
COLLECT_LTO_WRAPPER=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-99da523359e9333555585484eb3b8f854a98f1b4/libexec/gcc/x86_64-pc-linux-gnu/13.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --disable-multilib --disable-bootstrap
--enable-languages=c,c++
--prefix=/zdata/shaoli/compilers/ccbuilder-compilers/gcc-99da523359e9333555585484eb3b8f854a98f1b4
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.0.0 20221013 (experimental) (GCC) 
%
% gcc-tk -fsanitize=address -w -g -O0 a.c && ./a.out
%
% gcc-tk -fsanitize=address -w -g -O3 a.c && ./a.out
=================================================================
==1764559==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x602000000038 at pc 0x000000401210 bp 0x7fff57c272c0 sp 0x7fff57c272b8
WRITE of size 4 at 0x602000000038 thread T0
    #0 0x40120f in main
/zdata/shaoli/ubfuzz/synthesizer/bugs/gcc_work114/a.c:17
    #1 0x7f5e7a12a082 in __libc_start_main
(/lib/x86_64-linux-gnu/libc.so.6+0x24082) (BuildId:
1878e6b475720c7c51969e69ab2d276fae6d1dee)
    #2 0x4012bd in _start
(/zdata/shaoli/ubfuzz/synthesizer/bugs/gcc_work114/a.out+0x4012bd)

0x602000000038 is located 32 bytes to the right of 8-byte region
[0x602000000010,0x602000000018)
allocated by thread T0 here:
    #0 0x7f5e7a3c78bf in __interceptor_malloc
../../../../gcc/libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x40115f in main
/zdata/shaoli/ubfuzz/synthesizer/bugs/gcc_work114/a.c:12

SUMMARY: AddressSanitizer: heap-buffer-overflow
/zdata/shaoli/ubfuzz/synthesizer/bugs/gcc_work114/a.c:17 in main
Shadow bytes around the buggy address:
  0x0c047fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c047fff8000: fa fa 00 fa fa fa fa[fa]fa fa fa fa fa fa fa fa
  0x0c047fff8010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
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
==1764559==ABORTING
%
% cat a.c
typedef struct {
  int a
} b;

int d;

int main() {
  for (; d != 3; ++d) {
    char c[2];
    char e[5];
    char *h = e;
    int *g = malloc(2*sizeof(int));
    int i=19;
    b k;
    c[i] = 2;
    k.a = 0;
    g[c[i]] = 1;
  }
}
%