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parse_fdinfo: Don't advance pointer twice [BZ #31798] 

pidfd_getpid.c has

      /* Ignore invalid large values.  */
      if (INT_MULTIPLY_WRAPV (10, n, &n)
          || INT_ADD_WRAPV (n, *l++ - '0', &n))
        return -1;

For GCC older than GCC 7, INT_ADD_WRAPV(a, b, r) is defined as

   _GL_INT_OP_WRAPV (a, b, r, +, _GL_INT_ADD_RANGE_OVERFLOW)

and *l++ - '0' is evaluated twice.  Fix BZ #31798 by moving "l++" out of
the if statement.  Tested with GCC 6.4 and GCC 14.1.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
H.J. Lu 2024-05-25 05:13:41 -07:00
parent ab46c6ba6c
commit f981bf6b9d
1 changed files with 3 additions and 1 deletions
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4
sysdeps/unix/sysv/linux/pidfd_getpid.c
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@ -74,8 +74,10 @@ parse_fdinfo (const char *l, void *arg)
/* Ignore invalid large values. */
if (INT_MULTIPLY_WRAPV (10, n, &n)
|| INT_ADD_WRAPV (n, *l++ - '0', &n))
|| INT_ADD_WRAPV (n, *l - '0', &n))
return -1;
l++;
}
/* -1 indicates that the process is terminated. */