gcc/testsuite/gcc.dg/plugin/taint-pr112850-too-complex.c


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/* Reduced from false positive in Linux kernel in sound/core/rawmidi.c.

   With --param=analyzer-max-svalue-depth=12, the value being compared
   at the sanitization is too complex and becomes UNKNOWN; make sure
   this doesn't lead to a false positive.  */

/* { dg-do compile } */
/* { dg-options "-fanalyzer -O2 -Wanalyzer-symbol-too-complex --param=analyzer-max-svalue-depth=12" } */
/* { dg-require-effective-target analyzer } */

typedef unsigned long __kernel_ulong_t;
typedef __kernel_ulong_t __kernel_size_t;
typedef __kernel_size_t size_t;
typedef unsigned int gfp_t;

extern unsigned long copy_from_user(void* to, const void* from, unsigned long n);

extern
__attribute__((__alloc_size__(1)))
__attribute__((__malloc__)) void*
kvzalloc(size_t size, gfp_t flags);

struct snd_rawmidi_params
{
  int stream;
  size_t buffer_size;
};

char *newbuf;

static int
resize_runtime_buffer(struct snd_rawmidi_params* params)
{
  if (params->buffer_size < 32 || params->buffer_size > 1024L * 1024L) /* { dg-warning "symbol too complicated" } */
    return -22;
  newbuf = kvzalloc(params->buffer_size, /* { dg-bogus "use of attacker-controlled value '\\*params.buffer_size' as allocation size without upper-bounds checking" "PR analyzer/112850" } */
		    (((gfp_t)(0x400u | 0x800u)) | ((gfp_t)0x40u) | ((gfp_t)0x80u)));
  if (!newbuf)
    return -12;
  return 0;
}

long
snd_rawmidi_ioctl(unsigned long arg)
{
  void* argp = (void*)arg;
  struct snd_rawmidi_params params;
  if (copy_from_user(&params, argp, sizeof(struct snd_rawmidi_params)))
    return -14;
  return resize_runtime_buffer(&params);
}