Re: [PATCH net v2] tg3: Avoid NULL pointer dereference in tg3_io_error_detected()

[David Miller <davem@davemloft.net>]

From: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Date: Thu, 29 Sep 2016 13:24:08 -0300

> From: Milton Miller <miltonm@us.ibm.com>
> 
> While the driver is probing the adapter, an error may occur before the
> netdev structure is allocated and attached to pci_dev. In this case,
> not only netdev isn't available, but the tg3 private structure is also
> not available as it is just math from the NULL pointer, so dereferences
> must be skipped.
> 
> The following trace is seen when the error is triggered:
 ...
> This patch avoids the NULL pointer dereference by moving the access after
> the netdev NULL pointer check on tg3_io_error_detected(). Also, we add a
> check for netdev being NULL on tg3_io_resume() [suggested by Michael Chan].
> 
> Fixes: 0486a063b1ff ("tg3: prevent ifup/ifdown during PCI error recovery")
> Fixes: dfc8f370316b ("net/tg3: Release IRQs on permanent error")
> Tested-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> Signed-off-by: Milton Miller <miltonm@us.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
> ---
> 
>   * v2 changelog: added netdev NULL check on tg3_io_resume() as per
>     Michael Chan's suggestion.

Applied and queued up for -stable, thanks!