Re: [PATCH] leds: trigger: netdev: Fix kernel panic on interface rename trig notify

[Andrew Lunn <andrew@lunn.ch>]

On Sun, Feb 04, 2024 at 12:54:01AM +0100, Christian Marangi wrote:
> Commit d5e01266e7f5 ("leds: trigger: netdev: add additional specific link
> speed mode") in the various changes, reworked the way to set the LINKUP
> mode in commit cee4bd16c319 ("leds: trigger: netdev: Recheck
> NETDEV_LED_MODE_LINKUP on dev rename") and moved it to a generic function.
> 
> This changed the logic where, in the previous implementation the dev
> from the trigger event was used to check if the carrier was ok, but in
> the new implementation with the generic function, the dev in
> trigger_data is used instead.
> 
> This is problematic and cause a possible kernel panic due to the fact
> that the dev in the trigger_data still reference the old one as the
> new one (passed from the trigger event) still has to be hold and saved
> in the trigger_data struct (done in the NETDEV_REGISTER case).
> 
> On calling of get_device_state(), an invalid net_dev is used and this
> cause a kernel panic.
> 
> To handle this correctly, move the call to get_device_state() after the
> new net_dev is correctly set in trigger_data (in the NETDEV_REGISTER
> case) and correctly parse the new dev.
> 
> Fixes: d5e01266e7f5 ("leds: trigger: netdev: add additional specific link speed mode")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

This should have 'net' in the subject line, to indicate which tree its
for.

Otherwise:

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew