lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 30 Jun 2014 13:51:56 +0200
From:	Jiri Slaby <jslaby@...e.cz>
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	Stephane Grosjean <s.grosjean@...k-system.com>,
	Marc Kleine-Budde <mkl@...gutronix.de>,
	Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 3.12 095/181] can: peak_pci: prevent use after free at netdev removal

From: Stephane Grosjean <s.grosjean@...k-system.com>

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 <cbaker@....ri.cmu.edu>
Signed-off-by: Stephane Grosjean <s.grosjean@...k-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 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@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists