Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755778AbaF3L6Y (ORCPT ); Mon, 30 Jun 2014 07:58:24 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:52061 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753919AbaF3Lx0 (ORCPT ); Mon, 30 Jun 2014 07:53:26 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Stephane Grosjean , Marc Kleine-Budde , Jiri Slaby Subject: [PATCH 3.12 095/181] can: peak_pci: prevent use after free at netdev removal Date: Mon, 30 Jun 2014 13:51:56 +0200 Message-Id: X-Mailer: git-send-email 2.0.0 In-Reply-To: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> References: <61844d8e25eb8899b0836afa9796fa239db80f1f.1404128997.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephane Grosjean 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 0b5a958cf4df3a5cd578b861471e62138f55c85e upstream. As remarked by Christopher R. Baker in his post at http://marc.info/?l=linux-can&m=139707295706465&w=2 there's a possibility for an use after free condition at device removal. This simplified patch introduces an additional variable to prevent the issue. Thanks for catching this. Reported-by: Christopher R. Baker Signed-off-by: Stephane Grosjean Signed-off-by: Marc Kleine-Budde Signed-off-by: Jiri Slaby --- drivers/net/can/sja1000/peak_pci.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c index 6b6f0ad75090..7042f5faddd7 100644 --- a/drivers/net/can/sja1000/peak_pci.c +++ b/drivers/net/can/sja1000/peak_pci.c @@ -551,7 +551,7 @@ static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { struct sja1000_priv *priv; struct peak_pci_chan *chan; - struct net_device *dev; + struct net_device *dev, *prev_dev; void __iomem *cfg_base, *reg_base; u16 sub_sys_id, icr; int i, err, channels; @@ -687,11 +687,13 @@ failure_remove_channels: writew(0x0, cfg_base + PITA_ICR + 2); chan = NULL; - for (dev = pci_get_drvdata(pdev); dev; dev = chan->prev_dev) { - unregister_sja1000dev(dev); - free_sja1000dev(dev); + for (dev = pci_get_drvdata(pdev); dev; dev = prev_dev) { priv = netdev_priv(dev); chan = priv->priv; + prev_dev = chan->prev_dev; + + unregister_sja1000dev(dev); + free_sja1000dev(dev); } /* free any PCIeC resources too */ @@ -725,10 +727,12 @@ static void peak_pci_remove(struct pci_dev *pdev) /* Loop over all registered devices */ while (1) { + struct net_device *prev_dev = chan->prev_dev; + dev_info(&pdev->dev, "removing device %s\n", dev->name); unregister_sja1000dev(dev); free_sja1000dev(dev); - dev = chan->prev_dev; + dev = prev_dev; if (!dev) { /* do that only for first channel */ -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/