From: Hans de Goede <hdegoede@redhat.com>
To: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Cc: linux-kernel-mentees@lists.linuxfoundation.org,
syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com,
Marcel Holtmann <marcel@holtmann.org>,
Johan Hedberg <johan.hedberg@gmail.com>,
linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] bluetooth: hci_h5: fix memory leak in h5_close
Date: Fri, 16 Oct 2020 13:28:23 +0200 [thread overview]
Message-ID: <2a79ece2-c63b-a881-bc19-65b59952344f@redhat.com> (raw)
In-Reply-To: <20201007034803.7554-1-anant.thazhemadam@gmail.com>
Hi,
On 10/7/20 5:48 AM, Anant Thazhemadam wrote:
> If h5_close is called when !hu->serdev, h5 is directly freed.
> However, h5->rx_skb is not freed, which causes a memory leak.
>
> Freeing h5->rx_skb fixes this memory leak.
>
> In case hu->serdev exists, h5->rx_skb is then set to NULL,
> since we do not want to risk a potential NULL pointer
> dereference.
>
> Fixes: ce945552fde4 ("Bluetooth: hci_h5: Add support for serdev enumerated devices")
> Reported-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Tested-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>h5_close v4
> ---
> Changes in v4:
> * Free h5->rx_skb even when hu->serdev
> (Suggested by Hans de Goede <hdegoede@redhat.com>)
> * If hu->serdev, then assign h5->rx_skb = NULL
>
> Changes in v3:
> * Free h5->rx_skb when !hu->serdev, and fix the memory leak
> * Do not incorrectly and unnecessarily call serdev_device_close()
>
> Changes in v2:
> * Fixed the Fixes tag
>
> drivers/bluetooth/hci_h5.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
> index e41854e0d79a..39f9553caa5c 100644
> --- a/drivers/bluetooth/hci_h5.c
> +++ b/drivers/bluetooth/hci_h5.c
> @@ -245,11 +245,15 @@ static int h5_close(struct hci_uart *hu)
> skb_queue_purge(&h5->rel);
> skb_queue_purge(&h5->unrel);
>
> + kfree_skb(h5->rx_skb);
> +
> if (h5->vnd && h5->vnd->close)
> h5->vnd->close(h5);
>
> if (!hu->serdev)
> kfree(h5);
> + else
> + h5->rx_skb = NULL;
Please just do this unconditionally directly after
the kfree_skb()
So after this comment has been addressed the end result should
look like this:
skb_queue_purge(&h5->rel);
skb_queue_purge(&h5->unrel);
kfree_skb(h5->rx_skb);
h5->rx_skb = NULL;
if (h5->vnd && h5->vnd->close)
h5->vnd->close(h5);
if (!hu->serdev)
kfree(h5);
return 0;
Regards,
Hans
next prev parent reply other threads:[~2020-10-16 11:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 3:48 [PATCH v4] bluetooth: hci_h5: fix memory leak in h5_close Anant Thazhemadam
2020-10-16 11:28 ` Hans de Goede [this message]
2020-10-16 11:55 ` Anant Thazhemadam
2020-10-16 12:45 ` Hans de Goede
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=2a79ece2-c63b-a881-bc19-65b59952344f@redhat.com \
--to=hdegoede@redhat.com \
--cc=anant.thazhemadam@gmail.com \
--cc=johan.hedberg@gmail.com \
--cc=linux-bluetooth@vger.kernel.org \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marcel@holtmann.org \
--cc=syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.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).