[ 21/22] tg3: Avoid null pointer dereference in tg3_interrupt in netconsole mode

From: Greg Kroah-Hartman
Date: Tue Feb 12 2013 - 15:38:44 EST

3.0-stable review patch. If anyone has any objections, please let me know.


From: Nithin Nayak Sujir <nsujir@xxxxxxxxxxxx>

[ Upstream commit 9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 ]

When netconsole is enabled, logging messages generated during tg3_open
can result in a null pointer dereference for the uninitialized tg3
status block. Use the irq_sync flag to disable polling in the early
stages. irq_sync is cleared when the driver is enabling interrupts after
all initialization is completed.

Signed-off-by: Nithin Nayak Sujir <nsujir@xxxxxxxxxxxx>
Signed-off-by: Michael Chan <mchan@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/tg3.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -5662,6 +5662,9 @@ static void tg3_poll_controller(struct n
int i;
struct tg3 *tp = netdev_priv(dev);

+ if (tg3_irq_sync(tp))
+ return;
for (i = 0; i < tp->irq_cnt; i++)
tg3_interrupt(tp->napi[i].irq_vec, &tp->napi[i]);
@@ -14981,6 +14984,7 @@ static int __devinit tg3_init_one(struct
tp->pm_cap = pm_cap;
tp->rx_mode = TG3_DEF_RX_MODE;
tp->tx_mode = TG3_DEF_TX_MODE;
+ tp->irq_sync = 1;

if (tg3_debug > 0)
tp->msg_enable = tg3_debug;

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