程式語言 - GNU - CFLAGS -fsanitize=address

參考資訊：
https://hanpfei.github.io/2019/05/19/AddressSanitizer_on_linux/
https://stackoverflow.com/questions/37970758/how-to-use-addresssanitizer-with-gcc

main.c

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>

int main(void)
{
    int *p = malloc(sizeof(int));
    free(p);

    *p = 1000;
    return 0;
}

編譯、執行(沒有fsanitize)

$ gcc main.c -o main -ggdb
$ ./main

編譯、執行(使用fsanitize)

$ gcc main.c -o main -fsanitize=address -ggdb
$ ./main
    =================================================================
    ==31640==ERROR: AddressSanitizer: heap-use-after-free on address 0x602000000010 at pc 0x56107942f1ce bp 0x7ffe55b42ba0 sp 0x7ffe55b42b98
    WRITE of size 4 at 0x602000000010 thread T0
        #0 0x56107942f1cd in main /home/steward/Downloads/main.c:10
        #1 0x7f10e314509a in __libc_start_main ../csu/libc-start.c:308
        #2 0x56107942f0b9 in _start (/home/steward/Downloads/main+0x10b9)

    0x602000000010 is located 0 bytes inside of 4-byte region [0x602000000010,0x602000000014)
    freed by thread T0 here:
        #0 0x7f10e33c9fb0 in __interceptor_free (/lib/x86_64-linux-gnu/libasan.so.5+0xe8fb0)
        #1 0x56107942f196 in main /home/steward/Downloads/main.c:8
        #2 0x7f10e314509a in __libc_start_main ../csu/libc-start.c:308

    previously allocated by thread T0 here:
        #0 0x7f10e33ca330 in __interceptor_malloc (/lib/x86_64-linux-gnu/libasan.so.5+0xe9330)
        #1 0x56107942f186 in main /home/steward/Downloads/main.c:7
        #2 0x7f10e314509a in __libc_start_main ../csu/libc-start.c:308

    SUMMARY: AddressSanitizer: heap-use-after-free /home/steward/Downloads/main.c:10 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[fd]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
    ==31640==ABORTING

沒有fsanitize


使用fsanitize