question regarding nvc0_instmem_suspend()

Dan Carpenter error27 at gmail.com
Fri Aug 13 14:39:53 PDT 2010


Smatch thinks there is a buffer overflow in nvc0_instmem_suspend() and
I've looked at it, but I don't understand the code.

drivers/gpu/drm/nouveau/nvc0_instmem.c +152 nvc0_instmem_suspend(10)
	error: buffer overflow 'dev_priv->susres.ramin_copy' 16384 <= 1835008

   141  int
   142  nvc0_instmem_suspend(struct drm_device *dev)
   143  {
   144          struct drm_nouveau_private *dev_priv = dev->dev_private;
   145          int i;
   146
   147          dev_priv->susres.ramin_copy = vmalloc(65536);

	dev_priv->susres.ramin_copy is an array of 16384 u32 elements
	(65536 bytes).

   148          if (!dev_priv->susres.ramin_copy)
   149                  return -ENOMEM;
   150
   151          for (i = 0x700000; i < 0x710000; i += 4)
   152                  dev_priv->susres.ramin_copy[i/4] = nv_rd32(dev, i);

	0x700000 / 4 is 1835008 so we're way past the end of the array
	and then we get larger.

   153          return 0;
   154  }

Normally when I'm this confused it's because I'm missing something 
obvious.  :P  Can you help me out?

regards,
dan carpenter


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