1  #include <stdlib.h>
       2  #include <string.h>
       3  #include <stdint.h>
       4  #include <stdio.h>
       5  
       6  /* Wanalyzer-out-of-bounds tests for buffer overflows.  */
       7  
       8  /* Avoid folding of memcpy.  */
       9  typedef void * (*memcpy_t) (void *dst, const void *src, size_t n);
      10  
      11  static memcpy_t __attribute__((noinline))
      12  get_memcpy (void)
      13  {
      14    return memcpy;
      15  }
      16  
      17  
      18  /* Taken from CWE-787.  */
      19  void test1 (void)
      20  {
      21    int id_sequence[3];
      22  
      23    id_sequence[0] = 123;
      24    id_sequence[1] = 234;
      25    id_sequence[2] = 345;
      26    id_sequence[3] = 456; /* { dg-line test1 } */
      27  
      28    /* { dg-warning "stack-based buffer overflow" "warning" { target *-*-* } test1 } */
      29    /* { dg-message "write of 4 bytes to beyond the end of 'id_sequence'" "num bad bytes note" { target *-*-* } test1 } */
      30    /* { dg-message "valid subscripts for 'id_sequence' are '\\\[0\\\]' to '\\\[2\\\]'" "valid subscript note" { target *-*-* } test1 } */
      31  }
      32  
      33  void test2 (void)
      34  {
      35    int n = 4;
      36    int arr[4];
      37  
      38    for (int i = n - 1; i >= 0; i--)
      39      arr[i] = i;
      40  }
      41  
      42  void test3 (void)
      43  {
      44    int n = 4;
      45    int arr[4];
      46  
      47    for (int i = n; i >= 0; i--)
      48      arr[i] = i; /* { dg-line test3 } */
      49  
      50    /* { dg-warning "stack-based buffer overflow" "warning" { target *-*-* } test3 } */
      51    /* { dg-message "write of 4 bytes to beyond the end of 'arr'" "num bad bytes note" { target *-*-* } test3 } */
      52    /* { dg-message "valid subscripts for 'arr' are '\\\[0\\\]' to '\\\[3\\\]'" "valid subscript note" { target *-*-* } test3 } */
      53  }
      54  
      55  void test4 (void)
      56  {
      57    int *arr = malloc (4 * sizeof (int));
      58    if (!arr)
      59      return;
      60    
      61    int *last_el = arr + 3;
      62    *last_el = 3;
      63  
      64    free (arr);
      65  }
      66  
      67  void test5 (void)
      68  {
      69    int *arr = malloc (4 * sizeof (int));
      70    if (!arr)
      71      return;
      72    
      73    int *last_el = arr + 4;
      74    *last_el = 4; /* { dg-line test5 } */
      75  
      76    free (arr);
      77    /* { dg-warning "heap-based buffer overflow" "warning" { target *-*-* } test5 } */
      78    /* { dg-message "" "note" { target *-*-* } test5 } */
      79  }
      80  
      81  /* Taken from "A Provenance-aware Memory Object Model for C".  */
      82  int y = 2, x = 1; /* { dg-message "capacity" } */
      83  void test6 (void)
      84  {
      85    int *p = &x + 1;
      86    int *q = &y;
      87    printf ("Addresses: p=% p q=% p \n" , (void *) p, (void *) q);
      88    if (memcmp (&p , &q , sizeof (p)) == 0)
      89    {
      90      *p = 11; /* { dg-line test6b } */
      91      printf ("x=%d y=%d *p=%d *q=%d\n" , x, y, *p, *q);  /* { dg-line test6c } */
      92    }
      93  
      94    /* { dg-warning "buffer overflow" "warning" { target *-*-* } test6b } */
      95    /* { dg-message "" "note" { target *-*-* } test6b } */
      96    /* { dg-warning "buffer over-read" "warning" { target *-*-* } test6c } */
      97    /* { dg-message "" "note" { target *-*-* } test6c } */
      98  }
      99  
     100  extern int is_valid (void);
     101  
     102  int returnChunkSize (void *ptr)
     103  {
     104    /* If chunk info is valid, return the size of usable memory,
     105       else, return -1 to indicate an error.  */
     106    return is_valid () ? sizeof (*ptr) : -1;
     107  }
     108  
     109  /* Taken from CWE-787.  */
     110  void test7 (void)
     111  {
     112    memcpy_t fn = get_memcpy ();
     113  
     114    int destBuf[4];
     115    int srcBuf[4];
     116    fn (destBuf, srcBuf, returnChunkSize (destBuf)); /* { dg-line test7 } */
     117  
     118    // TODO: Should we handle widening_svalues as a follow-up?
     119    /* { dg-warning "over-read" "warning" { xfail *-*-* } test7 } */
     120    /* { dg-warning "use of uninitialized value" "uninit warning" { target *-*-* } test7 } */
     121    /* { dg-warning "overflow" "warning" { xfail *-*-* } test7 } */
     122  }