[Intel-wired-lan] [PATCH net v2] i40e/i40evf: proper update of the page_offset field

[Intel-wired-lan] [PATCH net v2] i40e/i40evf: proper update of the page_offset field

[=?unknown-8bit?q?Bj=C3=B6rn_T=C3=B6pel?=]

From: Bj?rn T?pel <bjorn.topel@intel.com>

In f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
i40e_build_skb updates the page_offset field with an incorrect offset,
which can lead to data corruption. This patch updates page_offset
correctly, by properly setting truesize.

Note that the bug only appears on architectures where PAGE_SIZE is
8192 or larger.

Fixes: f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
Signed-off-by: Bj?rn T?pel <bjorn.topel@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 3 ++-
 drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 29321a6167a6..cd894f4023b1 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1854,7 +1854,8 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = SKB_DATA_ALIGN(size);
+	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
+				SKB_DATA_ALIGN(I40E_SKB_PAD + size);
 #endif
 	struct sk_buff *skb;
 
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index dfe241a12ad0..12b02e530503 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -1190,7 +1190,8 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = SKB_DATA_ALIGN(size);
+	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
+				SKB_DATA_ALIGN(I40E_SKB_PAD + size);
 #endif
 	struct sk_buff *skb;
 
-- 
2.11.0

[Intel-wired-lan] [PATCH net v2] i40e/i40evf: proper update of the page_offset field

[Duyck, Alexander H]

On Mon, 2017-05-15 at 06:52 +0200, Bj?rn T?pel wrote:
> From: Bj?rn T?pel <bjorn.topel@intel.com>
> 
> In f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
> i40e_build_skb updates the page_offset field with an incorrect offset,
> which can lead to data corruption. This patch updates page_offset
> correctly, by properly setting truesize.
> 
> Note that the bug only appears on architectures where PAGE_SIZE is
> 8192 or larger.
> 
> Fixes: f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
> Signed-off-by: Bj?rn T?pel <bjorn.topel@intel.com>

Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>

> ---
>  drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 3 ++-
>  drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> index 29321a6167a6..cd894f4023b1 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> @@ -1854,7 +1854,8 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
>  #if (PAGE_SIZE < 8192)
>  	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
>  #else
> -	unsigned int truesize = SKB_DATA_ALIGN(size);
> +	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
> +				SKB_DATA_ALIGN(I40E_SKB_PAD + size);
>  #endif
>  	struct sk_buff *skb;
>  
> diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
> index dfe241a12ad0..12b02e530503 100644
> --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
> +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
> @@ -1190,7 +1190,8 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
>  #if (PAGE_SIZE < 8192)
>  	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
>  #else
> -	unsigned int truesize = SKB_DATA_ALIGN(size);
> +	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
> +				SKB_DATA_ALIGN(I40E_SKB_PAD + size);
>  #endif
>  	struct sk_buff *skb;
>  

[Intel-wired-lan] [PATCH net v2] i40e/i40evf: proper update of the page_offset field

[Bowers, AndrewX]

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces at osuosl.org] On
> Behalf Of Bj?rn T?pel
> Sent: Sunday, May 14, 2017 9:52 PM
> To: netdev at vger.kernel.org; intel-wired-lan at lists.osuosl.org
> Cc: Topel, Bjorn <bjorn.topel@intel.com>
> Subject: [Intel-wired-lan] [PATCH net v2] i40e/i40evf: proper update of the
> page_offset field
> 
> From: Bj?rn T?pel <bjorn.topel@intel.com>
> 
> In f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
> i40e_build_skb updates the page_offset field with an incorrect offset, which
> can lead to data corruption. This patch updates page_offset correctly, by
> properly setting truesize.
> 
> Note that the bug only appears on architectures where PAGE_SIZE is
> 8192 or larger.
> 
> Fixes: f8b45b74cc62 ("i40e/i40evf: Use build_skb to build frames")
> Signed-off-by: Bj?rn T?pel <bjorn.topel@intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 3 ++-
>  drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>