The ndo_start_xmit field in net_device_ops is expected to be of type
netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).

The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

The return type of ax88796c_start_xmit should be changed from int to
netdev_tx_t.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
---
 drivers/net/ethernet/asix/ax88796c_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/asix/ax88796c_main.c b/drivers/net/ethernet/asix/ax88796c_main.c
index 6ba5b024a7be..f1d610efd69e 100644
--- a/drivers/net/ethernet/asix/ax88796c_main.c
+++ b/drivers/net/ethernet/asix/ax88796c_main.c
@@ -381,7 +381,7 @@ static int ax88796c_hard_xmit(struct ax88796c_device *ax_local)
 	return 1;
 }
 
-static int
+static netdev_tx_t
 ax88796c_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
-- 
2.37.2.789.g6183377224-goog

Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 12 Sep 2022 12:40:30 -0700 you wrote:
> The ndo_start_xmit field in net_device_ops is expected to be of type
> netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
> 
> The return type of ax88796c_start_xmit should be changed from int to
> netdev_tx_t.
> 
> [...]

Here is the summary with links:
  - net: ax88796c: Fix return type of ax88796c_start_xmit
    https://git.kernel.org/netdev/net-next/c/fcb7c210a242

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

It was <2022-09-12 pon 12:40>, when Nathan Huckleberry wrote:
> The ndo_start_xmit field in net_device_ops is expected to be of type
> netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).
>
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
>
> The return type of ax88796c_start_xmit should be changed from int to
> netdev_tx_t.
>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: [...]
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>
> ---
>  drivers/net/ethernet/asix/ax88796c_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>

Acked-by: Lukasz Stelmach <l.stelmach@samsung.com>

> diff --git a/drivers/net/ethernet/asix/ax88796c_main.c b/drivers/net/ethernet/asix/ax88796c_main.c
> index 6ba5b024a7be..f1d610efd69e 100644
> --- a/drivers/net/ethernet/asix/ax88796c_main.c
> +++ b/drivers/net/ethernet/asix/ax88796c_main.c
> @@ -381,7 +381,7 @@ static int ax88796c_hard_xmit(struct ax88796c_device *ax_local)
>  	return 1;
>  }
>  
> -static int
> +static netdev_tx_t
>  ax88796c_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  {
>  	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);

-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics