From: Marcel Holtmann <marcel@holtmann.org>
To: Peilin Ye <yepeilin.cs@gmail.com>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
"open list:NETWORKING \[GENERAL\]" <netdev@vger.kernel.org>,
linux-kernel@vger.kernel.org,
Bluez mailing list <linux-bluetooth@vger.kernel.org>,
Jakub Kicinski <kuba@kernel.org>,
linux-kernel-mentees@lists.linuxfoundation.org,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [Linux-kernel-mentees] [PATCH net v2] Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt()
Date: Mon, 9 Nov 2020 13:16:53 +0100 [thread overview]
Message-ID: <AF20F58E-C800-45A8-A5B8-296DE4C0D906@holtmann.org> (raw)
In-Reply-To: <20200909071700.1100748-1-yepeilin.cs@gmail.com>
Hi Peilin,
> `num_reports` is not being properly checked. A malformed event packet with
> a large `num_reports` number makes hci_le_direct_adv_report_evt() read out
> of bounds. Fix it.
>
> Cc: stable@vger.kernel.org
> Fixes: 2f010b55884e ("Bluetooth: Add support for handling LE Direct Advertising Report events")
> Reported-and-tested-by: syzbot+24ebd650e20bd263ca01@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?extid=24ebd650e20bd263ca01
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> ---
> Change in v2:
> - add "Cc: stable@" tag.
>
> net/bluetooth/hci_event.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 4b7fc430793c..aec43ae488d1 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -5863,21 +5863,19 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
> struct sk_buff *skb)
> {
> u8 num_reports = skb->data[0];
> - void *ptr = &skb->data[1];
> + struct hci_ev_le_direct_adv_info *ev = (void *)&skb->data[1];
>
> - hci_dev_lock(hdev);
> + if (!num_reports || skb->len < num_reports * sizeof(*ev) + 1)
> + return;
>
> - while (num_reports--) {
> - struct hci_ev_le_direct_adv_info *ev = ptr;
> + hci_dev_lock(hdev);
>
> + for (; num_reports; num_reports--, ev++)
> process_adv_report(hdev, ev->evt_type, &ev->bdaddr,
> ev->bdaddr_type, &ev->direct_addr,
> ev->direct_addr_type, ev->rssi, NULL, 0,
> false);
>
> - ptr += sizeof(*ev);
> - }
> -
> hci_dev_unlock(hdev);
> }
patch has been applied to bluetooth-next tree.
Regards
Marcel
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
next prev parent reply other threads:[~2020-11-09 12:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-05 18:09 [Linux-kernel-mentees] [PATCH net] Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt() Peilin Ye
2020-09-09 7:17 ` [Linux-kernel-mentees] [PATCH net v2] " Peilin Ye
2020-11-09 12:16 ` Marcel Holtmann [this message]
2020-11-11 5:18 ` Peilin Ye
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AF20F58E-C800-45A8-A5B8-296DE4C0D906@holtmann.org \
--to=marcel@holtmann.org \
--cc=davem@davemloft.net \
--cc=johan.hedberg@gmail.com \
--cc=kuba@kernel.org \
--cc=linux-bluetooth@vger.kernel.org \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=yepeilin.cs@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).