2022-09-04 23:03:35

by Christian Marangi

[permalink] [raw]
Subject: [net PATCH] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data

of_device_get_match_data is called on priv->dev before priv->dev is
actually set. Move of_device_get_match_data after priv->dev is correctly
set to fix this kernel panic.

Fixes: 3bb0844e7bcd ("net: dsa: qca8k: cache match data to speed up access")
Signed-off-by: Christian Marangi <[email protected]>
---
drivers/net/dsa/qca/qca8k-8xxx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index 1d3e7782a71f..c181346388a4 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/drivers/net/dsa/qca/qca8k-8xxx.c
@@ -1889,9 +1889,9 @@ qca8k_sw_probe(struct mdio_device *mdiodev)
if (!priv)
return -ENOMEM;

- priv->info = of_device_get_match_data(priv->dev);
priv->bus = mdiodev->bus;
priv->dev = &mdiodev->dev;
+ priv->info = of_device_get_match_data(priv->dev);

priv->reset_gpio = devm_gpiod_get_optional(priv->dev, "reset",
GPIOD_ASIS);
--
2.37.2


2022-09-05 17:45:29

by Christian Marangi

[permalink] [raw]
Subject: Re: [net PATCH] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data

On Mon, Sep 05, 2022 at 07:50:39PM +0300, Vladimir Oltean wrote:
> On Sun, Sep 04, 2022 at 11:53:19PM +0200, Christian Marangi wrote:
> > of_device_get_match_data is called on priv->dev before priv->dev is
> > actually set. Move of_device_get_match_data after priv->dev is correctly
> > set to fix this kernel panic.
> >
> > Fixes: 3bb0844e7bcd ("net: dsa: qca8k: cache match data to speed up access")
> > Signed-off-by: Christian Marangi <[email protected]>
> > ---
>
> Did this ever work? Was it tested when you sent the big refactoring
> patch set?

I have to be honest here. I feel really embarrassed about this.
The short story is that the refactor was tested on Openwrt with 5.15 by
manually applying the changes. This fix was applied there but I forgot
to put it in the final series.

I notice this mistake only now that I'm backporting patches and the
manually applied fix was reset.

Again I'm really sorry.

--
Ansuel

2022-09-05 17:45:36

by Vladimir Oltean

[permalink] [raw]
Subject: Re: [net PATCH] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data

On Sun, Sep 04, 2022 at 11:53:19PM +0200, Christian Marangi wrote:
> of_device_get_match_data is called on priv->dev before priv->dev is
> actually set. Move of_device_get_match_data after priv->dev is correctly
> set to fix this kernel panic.
>
> Fixes: 3bb0844e7bcd ("net: dsa: qca8k: cache match data to speed up access")
> Signed-off-by: Christian Marangi <[email protected]>
> ---

Did this ever work? Was it tested when you sent the big refactoring
patch set?

2022-09-05 17:51:43

by Vladimir Oltean

[permalink] [raw]
Subject: Re: [net PATCH] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data

On Sun, Sep 04, 2022 at 11:53:19PM +0200, Christian Marangi wrote:
> of_device_get_match_data is called on priv->dev before priv->dev is
> actually set. Move of_device_get_match_data after priv->dev is correctly
> set to fix this kernel panic.
>
> Fixes: 3bb0844e7bcd ("net: dsa: qca8k: cache match data to speed up access")
> Signed-off-by: Christian Marangi <[email protected]>
> ---

Reviewed-by: Vladimir Oltean <[email protected]>

2022-09-06 10:21:01

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [net PATCH] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data

Hello:

This patch was applied to netdev/net.git (master)
by Paolo Abeni <[email protected]>:

On Sun, 4 Sep 2022 23:53:19 +0200 you wrote:
> of_device_get_match_data is called on priv->dev before priv->dev is
> actually set. Move of_device_get_match_data after priv->dev is correctly
> set to fix this kernel panic.
>
> Fixes: 3bb0844e7bcd ("net: dsa: qca8k: cache match data to speed up access")
> Signed-off-by: Christian Marangi <[email protected]>
>
> [...]

Here is the summary with links:
- [net] net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data
https://git.kernel.org/netdev/net/c/42b998d4aa59

You are awesome, thank you!
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