Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.4 01/43] can: peak_pci: prevent use after free at netdev removal | Date | Sat, 28 Jun 2014 10:45:52 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Stephane Grosjean <s.grosjean@peak-system.com>
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 <cbaker@rec.ri.cmu.edu> Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/net/can/sja1000/peak_pci.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
--- a/drivers/net/can/sja1000/peak_pci.c +++ b/drivers/net/can/sja1000/peak_pci.c @@ -547,7 +547,7 @@ static int __devinit peak_pci_probe(stru { 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; @@ -681,11 +681,13 @@ 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 */ @@ -719,10 +721,12 @@ static void __devexit peak_pci_remove(st /* 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 */
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