| Message ID | 20200710160915.228980-1-yepeilin.cs@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [Linux-kernel-mentees,v3] net/bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt() | expand |
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@syzkaller.appspotmail.com > Cc: stable@vger.kernel.org > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> > --- > 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
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 03a0759f2fc2..13d8802b8137 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4375,7 +4375,7 @@ static void hci_extended_inquiry_result_evt(struct hci_dev *hdev, BT_DBG("%s num_rsp %d", hdev->name, num_rsp); - if (!num_rsp) + if (!num_rsp || skb->len < num_rsp * sizeof(*info) + 1) return; if (hci_dev_test_flag(hdev, HCI_PERIODIC_INQ))
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@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> --- 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(-)