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authorDan Carpenter <error27@gmail.com>2010-04-06 19:31:26 +0300
committerTakashi Iwai <tiwai@suse.de>2010-04-06 18:52:39 +0200
commitb0cc58a25d04160d39a80e436847eaa2fbc5aa09 (patch)
treea20f259f6d2081e40ac979db8daad6b71ff7342c /sound
parenta0fd4345f928d72a56e27b23e4cd28c94bf36be5 (diff)
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>
Diffstat (limited to 'sound')
-rw-r--r--sound/pci/mixart/mixart.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c
index 7e8e7da592a..ea4256b08a3 100644
--- a/sound/pci/mixart/mixart.c
+++ b/sound/pci/mixart/mixart.c
@@ -1161,13 +1161,15 @@ static long snd_mixart_BA0_read(struct snd_info_entry *entry, void *file_private
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 @@ static long snd_mixart_BA1_read(struct snd_info_entry *entry, void *file_private
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;
}