si4713-i2c: avoid potential buffer overflow on si4713

Mauro Carvalho Chehab · torvalds · commit dc6b845044cc · 2011-07-18T09:12:21.000-07:00
While compiling it with Fedora 15, I noticed this issue:

  inlined from ‘si4713_write_econtrol_string’ at drivers/media/radio/si4713-i2c.c:1065:24:
  arch/x86/include/asm/uaccess_32.h:211:26: error: call to ‘copy_from_user_overflow’ declared with attribute error: copy_from_user() buffer size is not provably correct

Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@redhat.com&gt;
Acked-by: Sakari Ailus &lt;sakari.ailus@maxwell.research.nokia.com&gt;
Acked-by: Eduardo Valentin &lt;edubezval@gmail.com&gt;
Reviewed-by: Eugene Teo &lt;eugeneteo@kernel.sg&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/drivers/media/radio/si4713-i2c.c b/drivers/media/radio/si4713-i2c.c
@@ -1033,7 +1033,7 @@ static int si4713_write_econtrol_string(struct si4713_device *sdev,
 		char ps_name[MAX_RDS_PS_NAME + 1];
 
 		len = control->size - 1;
-		if (len > MAX_RDS_PS_NAME) {
+		if (len < 0 || len > MAX_RDS_PS_NAME) {
 			rval = -ERANGE;
 			goto exit;
 		}
@@ -1057,7 +1057,7 @@ static int si4713_write_econtrol_string(struct si4713_device *sdev,
 		char radio_text[MAX_RDS_RADIO_TEXT + 1];
 
 		len = control->size - 1;
-		if (len > MAX_RDS_RADIO_TEXT) {
+		if (len < 0 || len > MAX_RDS_RADIO_TEXT) {
 			rval = -ERANGE;
 			goto exit;
 		}
