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Subject[PATCH] media: v4l2-core: Fix Oops in ioctl
Syzbot reported a crash in video_usercopy().  It turns out when we
broke video_get_user() into a separate function then we accidentally
moved it outside the if block so it tries to memset a user pointer.

Reported-by: syzbot+9240c422be249a8422bd@syzkaller.appspotmail.com
Fixes: c8ef1a6076bf ("media: v4l2-core: split out data copy from video_usercopy")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Not actually tested. :( Sorry.

drivers/media/v4l2-core/v4l2-ioctl.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index b68ff06009cd..aaf83e254272 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -3205,12 +3205,12 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg,
parg = mbuf;
}

+ err = video_get_user((void __user *)arg, parg, orig_cmd,
+ &always_copy);
+ if (err)
+ goto out;
}

- err = video_get_user((void __user *)arg, parg, orig_cmd, &always_copy);
- if (err)
- goto out;
-
err = check_array_args(cmd, parg, &array_size, &user_ptr, &kernel_ptr);
if (err < 0)
goto out;
--
2.11.0
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