[PATCH net] net: tg3: fix NULL pointer dereference in tg3_io_error_detected and tg3_io_slot_reset

* [PATCH net] net: tg3: fix NULL pointer dereference in tg3_io_error_detected and tg3_io_slot_reset
@ 2013-08-13 18:45 Nithin Nayak Sujir
  2013-08-15  8:07 ` David Miller
  0 siblings, 1 reply; 7+ messages in thread
From: Nithin Nayak Sujir @ 2013-08-13 18:45 UTC (permalink / raw)
  To: davem
  Cc: netdev, Daniel Borkmann, Gavin Shan, Michael Chan, Nithin Nayak Sujir

From: Daniel Borkmann <dborkman@redhat.com>

Commit d8af4dfd8 ("net/tg3: Fix kernel crash") introduced a possible
NULL pointer dereference in tg3 driver when !netdev || !netif_running(netdev)
condition is met and netdev is NULL. Then, the jump to the 'done' label
calls dev_close() with a netdevice that is NULL. Therefore, only call
dev_close() when we have a netdevice, but one that is not running.

[ Add the same checks in tg3_io_slot_reset() per Gavin Shan - by Nithin
Nayak Sujir ]

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Michael Chan <mchan@broadcom.com>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index ddebc7a..0da2214 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17796,8 +17796,10 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev,
 
 done:
 	if (state == pci_channel_io_perm_failure) {
-		tg3_napi_enable(tp);
-		dev_close(netdev);
+		if (netdev) {
+			tg3_napi_enable(tp);
+			dev_close(netdev);
+		}
 		err = PCI_ERS_RESULT_DISCONNECT;
 	} else {
 		pci_disable_device(pdev);
@@ -17827,7 +17829,8 @@ static pci_ers_result_t tg3_io_slot_reset(struct pci_dev *pdev)
 	rtnl_lock();
 
 	if (pci_enable_device(pdev)) {
-		netdev_err(netdev, "Cannot re-enable PCI device after reset.\n");
+		dev_err(&pdev->dev,
+			"Cannot re-enable PCI device after reset.\n");
 		goto done;
 	}
 
@@ -17835,7 +17838,7 @@ static pci_ers_result_t tg3_io_slot_reset(struct pci_dev *pdev)
 	pci_restore_state(pdev);
 	pci_save_state(pdev);
 
-	if (!netif_running(netdev)) {
+	if (!netdev || !netif_running(netdev)) {
 		rc = PCI_ERS_RESULT_RECOVERED;
 		goto done;
 	}
@@ -17847,7 +17850,7 @@ static pci_ers_result_t tg3_io_slot_reset(struct pci_dev *pdev)
 	rc = PCI_ERS_RESULT_RECOVERED;
 
 done:
-	if (rc != PCI_ERS_RESULT_RECOVERED && netif_running(netdev)) {
+	if (rc != PCI_ERS_RESULT_RECOVERED && netdev && netif_running(netdev)) {
 		tg3_napi_enable(tp);
 		dev_close(netdev);
 	}
-- 
1.8.1.4

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