net: tg3: fix NULL pointer dereference in tg3_io_error_detected and tg3_io_slot_reset

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>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index ddebc7a5dda0d14f32e8df6b7066b2d75c752a72..0da2214ef1b9e895903612809b21ed070cf32fa3 100644 (file)
--- 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);
        }