From: "Ahmed S. Darwish" <darwish.07@gmail.com>
To: Olivier Sobrie <olivier@sobrie.be>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>,
Wolfgang Grandegger <wg@grandegger.com>,
Marc Kleine-Budde <mkl@pengutronix.de>,
"David S. Miller" <davem@davemloft.net>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Linux-CAN <linux-can@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] can: kvaser_usb: Don't free packets when tight on URBs
Date: Wed, 24 Dec 2014 17:52:46 +0200 [thread overview]
Message-ID: <20141224155246.GB27062@vivalin-002> (raw)
In-Reply-To: <CAEM=fMqwt+=1Du74qu3dLJ7-OLnypkhJZ_N8uSWAAtzTLazmOg@mail.gmail.com>
Hi Olivier,
On Wed, Dec 24, 2014 at 01:31:20PM +0100, Olivier Sobrie wrote:
> Hello Ahmed,
>
> On Tue, Dec 23, 2014 at 05:46:54PM +0200, Ahmed S. Darwish wrote:
> > From: Ahmed S. Darwish <ahmed.darwish@valeo.com>
> >
> > Flooding the Kvaser CAN to USB dongle with multiple reads and
> > writes in high frequency caused seemingly-random panics in the
> > kernel.
> >
> > On further inspection, it seems the driver erroneously freed the
> > to-be-transmitted packet upon getting tight on URBs and returning
> > NETDEV_TX_BUSY, leading to invalid memory writes and double frees
> > at a later point in time.
> >
> > Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
>
> Thank you for the fix.
>
> > ---
> > drivers/net/can/usb/kvaser_usb.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > (Generated over 3.19.0-rc1)
> >
> > diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> > index 541fb7a..34c35d8 100644
> > --- a/drivers/net/can/usb/kvaser_usb.c
> > +++ b/drivers/net/can/usb/kvaser_usb.c
> > @@ -1286,6 +1286,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> > struct kvaser_msg *msg;
> > int i, err;
> > int ret = NETDEV_TX_OK;
> > + bool kfree_skb_on_error = true;
> >
> > if (can_dropped_invalid_skb(netdev, skb))
> > return NETDEV_TX_OK;
> > @@ -1336,6 +1337,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> >
> > if (!context) {
> > netdev_warn(netdev, "cannot find free context\n");
> > + kfree_skb_on_error = false;
>
> Instead of using an extra variable, you can also set skb to NULL here.
> Or maybe better, you can move the dev_kfree_skb() in the two previous
> tests (in the check of variables urb and buf).
>
Nice, I'll move dev_kfree_skb() to the two earlier tests then.
Thanks,
P.S. mailer and patch identation; had to manually fix them
before replying (but thanks for the quick review, ofc ;-))
> Thank you,
>
> Olivier
>
> > ret = NETDEV_TX_BUSY;
> > goto releasebuf;
> > }
> > @@ -1364,8 +1366,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> > if (unlikely(err)) {
> > can_free_echo_skb(netdev, context->echo_index);
> >
> > - skb = NULL; /* set to NULL to avoid double free in
> > - * dev_kfree_skb(skb) */
> > + kfree_skb_on_error = false;
> >
> > atomic_dec(&priv->active_tx_urbs);
> > usb_unanchor_urb(urb);
> > @@ -1389,7 +1390,8 @@ releasebuf:
> > nobufmem:
> > usb_free_urb(urb);
> > nourbmem:
> > - dev_kfree_skb(skb);
> > + if (kfree_skb_on_error)
> > + dev_kfree_skb(skb);
> > return ret;
> > }
> >
next prev parent reply other threads:[~2014-12-24 15:52 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-23 15:46 [PATCH] can: kvaser_usb: Don't free packets when tight on URBs Ahmed S. Darwish
2014-12-23 15:53 ` [PATCH] can: kvaser_usb: Add support for the Usbcan-II family Ahmed S. Darwish
2014-12-24 12:36 ` Olivier Sobrie
2014-12-24 15:04 ` Ahmed S. Darwish
2014-12-28 21:51 ` Olivier Sobrie
2014-12-30 15:33 ` Ahmed S. Darwish
2014-12-31 12:13 ` Olivier Sobrie
2014-12-24 12:31 ` [PATCH] can: kvaser_usb: Don't free packets when tight on URBs Olivier Sobrie
2014-12-24 15:52 ` Ahmed S. Darwish [this message]
2014-12-24 23:56 ` [PATCH v2 1/4] " Ahmed S. Darwish
2014-12-24 23:59 ` [PATCH v2 2/4] can: kvaser_usb: Reset all URB tx contexts upon channel close Ahmed S. Darwish
2014-12-25 0:02 ` [PATCH v2 3/4] can: kvaser_usb: Don't send a RESET_CHIP for non-existing channels Ahmed S. Darwish
2014-12-25 0:04 ` [PATCH v2 4/4] can: kvaser_usb: Add support for the Usbcan-II family Ahmed S. Darwish
2014-12-28 21:54 ` [PATCH v2 3/4] can: kvaser_usb: Don't send a RESET_CHIP for non-existing channels Olivier Sobrie
2014-12-25 2:50 ` [PATCH v2 1/4] can: kvaser_usb: Don't free packets when tight on URBs Greg KH
2014-12-25 9:38 ` Ahmed S. Darwish
2014-12-28 21:52 ` Olivier Sobrie
2015-01-01 21:59 ` [PATCH] " Stephen Hemminger
2015-01-03 14:34 ` Ahmed S. Darwish
2015-01-05 17:49 ` [PATCH v3 1/4] " Ahmed S. Darwish
2015-01-05 17:52 ` [PATCH v3 2/4] can: kvaser_usb: Reset all URB tx contexts upon channel close Ahmed S. Darwish
2015-01-05 17:57 ` [PATCH v3 3/4] can: kvaser_usb: Don't send a RESET_CHIP for non-existing channels Ahmed S. Darwish
2015-01-05 18:31 ` [PATCH v3 4/4] can: kvaser_usb: Add support for the Usbcan-II family Ahmed S. Darwish
2015-01-08 11:53 ` Marc Kleine-Budde
2015-01-08 15:19 ` Ahmed S. Darwish
2015-01-12 11:51 ` Marc Kleine-Budde
2015-01-12 12:26 ` Ahmed S. Darwish
2015-01-12 12:34 ` Marc Kleine-Budde
2015-01-09 3:06 ` Ahmed S. Darwish
2015-01-09 14:05 ` Marc Kleine-Budde
2015-01-08 9:59 ` [PATCH v3 1/4] can: kvaser_usb: Don't free packets when tight on URBs Marc Kleine-Budde
2015-01-11 20:05 ` [PATCH v4 00/04] can: Introduce support for Kvaser USBCAN-II devices Ahmed S. Darwish
2015-01-11 20:11 ` [PATCH v4 01/04] can: kvaser_usb: Don't dereference skb after a netif_rx() devices Ahmed S. Darwish
2015-01-11 20:15 ` [PATCH v4 2/4] can: kvaser_usb: Update error counters before exiting on OOM Ahmed S. Darwish
2015-01-11 20:36 ` [PATCH v4 3/4] can: kvaser_usb: Add support for the Usbcan-II family Ahmed S. Darwish
2015-01-11 20:45 ` [PATCH v4 4/4] can: kvaser_usb: Retry first bulk transfer on -ETIMEDOUT Ahmed S. Darwish
2015-01-11 20:51 ` Marc Kleine-Budde
2015-01-12 10:14 ` Ahmed S. Darwish
2015-01-12 10:25 ` Marc Kleine-Budde
2015-01-12 13:33 ` Olivier Sobrie
2015-01-12 13:50 ` Ahmed S. Darwish
2015-01-12 11:20 ` [PATCH v4 3/4] can: kvaser_usb: Add support for the Usbcan-II family Ahmed S. Darwish
2015-01-12 11:43 ` Marc Kleine-Budde
2015-01-12 12:07 ` Ahmed S. Darwish
2015-01-12 12:36 ` Ahmed S. Darwish
2015-01-12 13:53 ` Olivier Sobrie
2015-01-18 20:12 ` Ahmed S. Darwish
2015-01-18 20:13 ` Marc Kleine-Budde
2015-01-12 11:09 ` [PATCH v4 2/4] can: kvaser_usb: Update error counters before exiting on OOM Marc Kleine-Budde
2015-01-12 20:36 ` Ahmed S. Darwish
2015-01-16 14:39 ` Marc Kleine-Budde
2015-01-11 20:49 ` [PATCH v4 01/04] can: kvaser_usb: Don't dereference skb after a netif_rx() Ahmed S. Darwish
2015-01-12 11:05 ` Marc Kleine-Budde
2015-01-20 21:44 ` [PATCH v5 1/5] can: kvaser_usb: Update net interface state before exiting on OOM Ahmed S. Darwish
2015-01-20 21:45 ` [PATCH v5 2/5] can: kvaser_usb: Consolidate and unify state change handling Ahmed S. Darwish
2015-01-20 21:47 ` [PATCH v5 3/5] can: kvaser_usb: Fix state handling upon BUS_ERROR events Ahmed S. Darwish
2015-01-20 21:48 ` [PATCH v5 4/5] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT Ahmed S. Darwish
2015-01-20 21:50 ` [PATCH v5 5/5] can: kvaser_usb: Add support for the USBcan-II family Ahmed S. Darwish
2015-01-21 12:24 ` [PATCH v5 4/5] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT Sergei Shtylyov
2015-01-25 11:59 ` Ahmed S. Darwish
2015-01-21 10:33 ` [PATCH v5 2/5] can: kvaser_usb: Consolidate and unify state change handling Andri Yngvason
2015-01-21 10:44 ` Marc Kleine-Budde
2015-01-21 11:00 ` Andri Yngvason
2015-01-21 11:53 ` Wolfgang Grandegger
2015-01-21 14:43 ` Ahmed S. Darwish
2015-01-21 15:00 ` Andri Yngvason
2015-01-21 15:36 ` Ahmed S. Darwish
2015-01-21 16:13 ` Wolfgang Grandegger
2015-01-23 6:07 ` Ahmed S. Darwish
2015-01-23 10:32 ` Andri Yngvason
2015-01-25 2:43 ` Ahmed S. Darwish
2015-01-26 10:21 ` Andri Yngvason
2015-01-21 16:37 ` Andri Yngvason
2015-01-21 16:20 ` Andri Yngvason
2015-01-21 22:59 ` Marc Kleine-Budde
2015-01-22 10:14 ` Andri Yngvason
2015-01-25 2:49 ` Ahmed S. Darwish
2015-01-25 3:21 ` Ahmed S. Darwish
2015-01-26 5:17 ` [PATCH v6 0/7] can: kvaser_usb: Leaf bugfixes and USBCan-II support Ahmed S. Darwish
2015-01-26 5:20 ` [PATCH v6 1/7] can: kvaser_usb: Do not sleep in atomic context Ahmed S. Darwish
2015-01-26 5:22 ` [PATCH v6 2/7] can: kvaser_usb: Send correct context to URB completion Ahmed S. Darwish
2015-01-26 5:24 ` [PATCH v6 3/7] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT Ahmed S. Darwish
2015-01-26 5:25 ` [PATCH v6 4/7] can: kvaser_usb: Fix state handling upon BUS_ERROR events Ahmed S. Darwish
2015-01-26 5:27 ` [PATCH v6 5/7] can: kvaser_usb: Update interface state before exiting on OOM Ahmed S. Darwish
2015-01-26 5:29 ` [PATCH v6 6/7] can: kvaser_usb: Consolidate and unify state change handling Ahmed S. Darwish
2015-01-26 5:33 ` [PATCH v6 7/7] can: kvaser_usb: Add support for the USBcan-II family Ahmed S. Darwish
2015-01-26 10:34 ` Andri Yngvason
2015-01-26 10:26 ` [PATCH v6 6/7] can: kvaser_usb: Consolidate and unify state change handling Andri Yngvason
2015-01-26 10:28 ` [PATCH v6 5/7] can: kvaser_usb: Update interface state before exiting on OOM Andri Yngvason
2015-01-26 10:50 ` Marc Kleine-Budde
2015-01-26 10:52 ` Andri Yngvason
2015-01-26 10:53 ` Marc Kleine-Budde
2015-01-26 9:55 ` [PATCH v6 0/7] can: kvaser_usb: Leaf bugfixes and USBCan-II support Marc Kleine-Budde
2015-01-26 10:07 ` Marc Kleine-Budde
2015-01-26 10:56 ` Marc Kleine-Budde
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=20141224155246.GB27062@vivalin-002 \
--to=darwish.07@gmail.com \
--cc=davem@davemloft.net \
--cc=linux-can@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mkl@pengutronix.de \
--cc=netdev@vger.kernel.org \
--cc=olivier@sobrie.be \
--cc=paul.gortmaker@windriver.com \
--cc=socketcan@hartkopp.net \
--cc=wg@grandegger.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).