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authorStephane Grosjean <s.grosjean@peak-system.com>2014-05-20 13:38:56 +0400
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-05-21 10:17:03 +0400
commit0b5a958cf4df3a5cd578b861471e62138f55c85e (patch)
treebe02fbf4f83f6a1a9c89239951c6da0ba6720355 /drivers/net/can
parent78ff4be45a4c51d8fb21ad92e4fabb467c6c3eeb (diff)
downloadlinux-0b5a958cf4df3a5cd578b861471e62138f55c85e.tar.xz
can: peak_pci: prevent use after free at netdev removal
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. Cc: linux-stable <stable@vger.kernel.org> 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>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/sja1000/peak_pci.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c
index c540e3d12e3d..564933ae218c 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;
@@ -688,11 +688,13 @@ 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 */
@@ -726,10 +728,12 @@ 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 */