Re: [Linux-kernel-mentees] [PATCH v3] net/bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()

From: Marcel Holtmann
Date: Fri Jul 10 2020 - 13:08:55 EST


Hi Peilin,

> Check upon `num_rsp` is insufficient. A malformed event packet with a
> large `num_rsp` number makes hci_extended_inquiry_result_evt() go out
> of bounds. Fix it.
>
> This patch fixes the following syzbot bug:
>
> https://syzkaller.appspot.com/bug?id=4bf11aa05c4ca51ce0df86e500fce486552dc8d2
>
> Reported-by: syzbot+d8489a79b781849b9c46@xxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
> ---
> Change in v3:
> - Minimum `skb->len` requirement was 1 byte inaccurate since `info`
> starts from `skb->data + 1`. Fix it.
>
> Changes in v2:
> - Use `skb->len` instead of `skb->truesize` as the length limit.
> - Leave `num_rsp` as of type `int`.
>
> net/bluetooth/hci_event.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel