[PATCH net-next] nfp: flower: add check for flower VF netdevs for get/set_eeprom

[PATCH net-next] nfp: flower: add check for flower VF netdevs for get/set_eeprom

[Simon Horman]

From: James Hershaw <james.hershaw@corigine.com>

Move the nfp_net_get_port_mac_by_hwinfo() check to ahead in the
get/set_eeprom() functions to in order to check for a VF netdev, which
this function does not support.

It is debatable if this is a fix or an enhancement, and we have chosen
to go for the latter. It does address a problem introduced by
commit 74b4f1739d4e ("nfp: flower: change get/set_eeprom logic and enable for flower reps").
However, the ethtool->len == 0 check avoids the problem manifesting as a
run-time bug (NULL pointer dereference of app).

Signed-off-by: James Hershaw <james.hershaw@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
index e9d228d7a95d..807b86667bca 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
@@ -1908,12 +1908,12 @@ nfp_net_get_eeprom(struct net_device *netdev,
 	struct nfp_app *app = nfp_app_from_netdev(netdev);
 	u8 buf[NFP_EEPROM_LEN] = {};
 
-	if (eeprom->len == 0)
-		return -EINVAL;
-
 	if (nfp_net_get_port_mac_by_hwinfo(netdev, buf))
 		return -EOPNOTSUPP;
 
+	if (eeprom->len == 0)
+		return -EINVAL;
+
 	eeprom->magic = app->pdev->vendor | (app->pdev->device << 16);
 	memcpy(bytes, buf + eeprom->offset, eeprom->len);
 
@@ -1927,15 +1927,15 @@ nfp_net_set_eeprom(struct net_device *netdev,
 	struct nfp_app *app = nfp_app_from_netdev(netdev);
 	u8 buf[NFP_EEPROM_LEN] = {};
 
+	if (nfp_net_get_port_mac_by_hwinfo(netdev, buf))
+		return -EOPNOTSUPP;
+
 	if (eeprom->len == 0)
 		return -EINVAL;
 
 	if (eeprom->magic != (app->pdev->vendor | app->pdev->device << 16))
 		return -EINVAL;
 
-	if (nfp_net_get_port_mac_by_hwinfo(netdev, buf))
-		return -EOPNOTSUPP;
-
 	memcpy(buf + eeprom->offset, bytes, eeprom->len);
 	if (nfp_net_set_port_mac_by_hwinfo(netdev, buf))
 		return -EOPNOTSUPP;
-- 
2.30.2

Re: [PATCH net-next] nfp: flower: add check for flower VF netdevs for get/set_eeprom

[Leon Romanovsky]

On Mon, Feb 06, 2023 at 04:48:36PM +0100, Simon Horman wrote:
> From: James Hershaw <james.hershaw@corigine.com>
> 
> Move the nfp_net_get_port_mac_by_hwinfo() check to ahead in the
> get/set_eeprom() functions to in order to check for a VF netdev, which
> this function does not support.
> 
> It is debatable if this is a fix or an enhancement, and we have chosen
> to go for the latter. It does address a problem introduced by
> commit 74b4f1739d4e ("nfp: flower: change get/set_eeprom logic and enable for flower reps").
> However, the ethtool->len == 0 check avoids the problem manifesting as a
> run-time bug (NULL pointer dereference of app).
> 
> Signed-off-by: James Hershaw <james.hershaw@corigine.com>
> Reviewed-by: Louis Peens <louis.peens@corigine.com>
> Signed-off-by: Simon Horman <simon.horman@corigine.com>
> ---
>  drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net-next] nfp: flower: add check for flower VF netdevs for get/set_eeprom

[patchwork-bot+netdevbpf]

Hello:

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

On Mon,  6 Feb 2023 16:48:36 +0100 you wrote:
> From: James Hershaw <james.hershaw@corigine.com>
> 
> Move the nfp_net_get_port_mac_by_hwinfo() check to ahead in the
> get/set_eeprom() functions to in order to check for a VF netdev, which
> this function does not support.
> 
> It is debatable if this is a fix or an enhancement, and we have chosen
> to go for the latter. It does address a problem introduced by
> commit 74b4f1739d4e ("nfp: flower: change get/set_eeprom logic and enable for flower reps").
> However, the ethtool->len == 0 check avoids the problem manifesting as a
> run-time bug (NULL pointer dereference of app).
> 
> [...]

Here is the summary with links:
  - [net-next] nfp: flower: add check for flower VF netdevs for get/set_eeprom
    https://git.kernel.org/netdev/net-next/c/f817554786dd

You are awesome, thank you!
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