`clipcount' is from userspace and thus needs validation. Otherwise,
a large `clipcount' could overflow the vmalloc() size, leading to
out-of-bounds access.
| setup_window()
| zoran_s_fmt_vid_overlay()
| __video_do_ioctl()
| video_ioctl2()
Use 2048 as the maximum `clipcount'. Also change the corresponding
parameter type to `unsigned int'.
Signed-off-by: Xi Wang <xi.w...@gmail.com>
---
The upper bound `2048' is from get_v4l2_window32() in
drivers/media/video/v4l2-ioctl.c.
bt8xx and saa7134 also use the bound for `clipcount'.
---
drivers/media/video/zoran/zoran_driver.c | 20 +++++++++++++++++---
1 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/media/video/zoran/zoran_driver.c
b/drivers/media/video/zoran/zoran_driver.c
index 4c09ab7..c573109 100644
--- a/drivers/media/video/zoran/zoran_driver.c
+++ b/drivers/media/video/zoran/zoran_driver.c
@@ -1131,8 +1131,14 @@ static int setup_fbuffer(struct zoran_fh *fh,
}
-static int setup_window(struct zoran_fh *fh, int x, int y, int width, int
height,
- struct v4l2_clip __user *clips, int clipcount, void __user *bitmap)
+static int setup_window(struct zoran_fh *fh,
+ int x,
+ int y,
+ int width,
+ int height,
+ struct v4l2_clip __user *clips,
+ unsigned int clipcount,
+ void __user *bitmap)
{
struct zoran *zr = fh->zr;
struct v4l2_clip *vcp = NULL;
@@ -1155,6 +1161,14 @@ static int setup_window(struct zoran_fh *fh, int x, int
y, int width, int height
return -EINVAL;
}
+ if (clipcount > 2048) {
+ dprintk(1,
+ KERN_ERR
+ "%s: %s - invalid clipcount\n",
+ ZR_DEVNAME(zr), __func__);
+ return -EINVAL;
+ }
+
/*
* The video front end needs 4-byte alinged line sizes, we correct that
* silently here if necessary
@@ -1218,7 +1232,7 @@ static int setup_window(struct zoran_fh *fh, int x, int
y, int width, int height
(width * height + 7) / 8)) {
return -EFAULT;
}
- } else if (clipcount > 0) {
+ } else if (clipcount) {
/* write our own bitmap from the clips */
vcp = vmalloc(sizeof(struct v4l2_clip) * (clipcount + 4));
if (vcp == NULL) {
--
1.7.5.4
--
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