Subject: Re: [PATCH v2] e1000e: Modify tx/rx configurations to avoid null pointer dereferences in e1000_open

From: Jeff Kirsher <[email-masked]>
Date: Wed, 05 Aug 2015 03:43:49 -0700

On Wed, 2015-08-05 at 18:16 +0800, Jia-Ju Bai wrote:
> When e1000e_setup_rx_resources is failed in e1000_open,
> e1000e_free_tx_resources in "err_setup_rx" segment is executed.
> "writel(0, tx_ring->head)" statement in e1000_clean_tx_ring
> in e1000e_free_tx_resources will cause a null poonter
> dereference(crash),
> because "tx_ring->head" is only assigned in e1000_configure_tx
> in e1000_configure, but it is after e1000e_setup_rx_resources.
> 
> This patch moves head/tail register writing to e1000_configure_tx/rx, 
> which can fix this problem. It is inspired by igb_configure_tx_ring 
> in the igb driver.
> 
> Specially, thank Alexander Duyck for his valuable suggestion.
> 
> Signed-off-by: Jia-Ju Bai <[email-masked]>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c |   24
> ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)

Is your intention that this patch replace the existing patch:
http://patchwork.ozlabs.org/patch/502990/
...which is currently in my queue?