[media] atomisp2: array underflow in ap1302_enum_frame_size()

Commit Message

Dan Carpenter July 19, 2017, 9:56 a.m. UTC

The problem is this code from ap1302_enum_frame_size():

   738          int index = fse->index;
   739  
   740          mutex_lock(&dev->input_lock);
   741          context = ap1302_get_context(sd);
   742          if (index >= dev->cntx_res[context].res_num) {
   743                  mutex_unlock(&dev->input_lock);
   744                  return -EINVAL;
   745          }
   746  
   747          res_table = dev->cntx_res[context].res_table;
   748          fse->min_width = res_table[index].width;

"fse->index" is a u32 that come from the user.  We want negative values
of "index" to be treated as -EINVAL but they're not so we can read from
before the start of the res_table[] array.

I've fixed this by making "res_num" a u32.  I made "cur_res" a u32 as
well, just for consistency.

Fixes: a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2")
Signed-off-by: Dan Carpenter <[e-mail]>

Patch

diff --git a/drivers/staging/media/atomisp/i2c/ap1302.h b/drivers/staging/media/atomisp/i2c/ap1302.h
index 9341232c580d..4d0b181a9671 100644
--- a/drivers/staging/media/atomisp/i2c/ap1302.h
+++ b/drivers/staging/media/atomisp/i2c/ap1302.h
@@ -158,8 +158,8 @@  struct ap1302_res_struct {
 };
 
 struct ap1302_context_res {
-	s32 res_num;
-	s32 cur_res;
+	u32 res_num;
+	u32 cur_res;
 	struct ap1302_res_struct *res_table;
 };