ALSA: mixart: range checking proc file
The original code doesn't take into consideration that the value of
MIXART_BA0_SIZE - pos can be less than zero which would lead to a large
unsigned value for "count".
Also I moved the check that read size is a multiple of 4 bytes below
the code that adjusts "count".
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: <stable@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c
index 7e8e7da..ea4256b 100644
--- a/sound/pci/mixart/mixart.c
+++ b/sound/pci/mixart/mixart.c
@@ -1161,13 +1161,15 @@
unsigned long count, unsigned long pos)
{
struct mixart_mgr *mgr = entry->private_data;
+ unsigned long maxsize;
- count = count & ~3; /* make sure the read size is a multiple of 4 bytes */
- if(count <= 0)
+ if (pos >= MIXART_BA0_SIZE)
return 0;
- if(pos + count > MIXART_BA0_SIZE)
- count = (long)(MIXART_BA0_SIZE - pos);
- if(copy_to_user_fromio(buf, MIXART_MEM( mgr, pos ), count))
+ maxsize = MIXART_BA0_SIZE - pos;
+ if (count > maxsize)
+ count = maxsize;
+ count = count & ~3; /* make sure the read size is a multiple of 4 bytes */
+ if (copy_to_user_fromio(buf, MIXART_MEM(mgr, pos), count))
return -EFAULT;
return count;
}
@@ -1180,13 +1182,15 @@
unsigned long count, unsigned long pos)
{
struct mixart_mgr *mgr = entry->private_data;
+ unsigned long maxsize;
- count = count & ~3; /* make sure the read size is a multiple of 4 bytes */
- if(count <= 0)
+ if (pos > MIXART_BA1_SIZE)
return 0;
- if(pos + count > MIXART_BA1_SIZE)
- count = (long)(MIXART_BA1_SIZE - pos);
- if(copy_to_user_fromio(buf, MIXART_REG( mgr, pos ), count))
+ maxsize = MIXART_BA1_SIZE - pos;
+ if (count > maxsize)
+ count = maxsize;
+ count = count & ~3; /* make sure the read size is a multiple of 4 bytes */
+ if (copy_to_user_fromio(buf, MIXART_REG(mgr, pos), count))
return -EFAULT;
return count;
}
