[PATCH] platform/chrome: cros_ec_debugfs: unregister panic notifier on remove

[PATCH] platform/chrome: cros_ec_debugfs: unregister panic notifier on remove

[Pengpeng Hou]

cros_ec_debugfs_probe() registers a panic notifier whose callback
recovers struct cros_ec_debugfs with container_of() and can schedule or
flush the console log work.

cros_ec_debugfs_remove() removes debugfs state and cleans up the console
log buffer, but it leaves the notifier registered.  A later panic
notification can therefore call back into freed debugfs state.

Unregister the panic notifier before tearing down the debugfs and log
state.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
---
 drivers/platform/chrome/cros_ec_debugfs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
index d10f9561990c..a19de7d418fe 100644
--- a/drivers/platform/chrome/cros_ec_debugfs.c
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -530,6 +530,8 @@ static void cros_ec_debugfs_remove(struct platform_device *pd)
 {
 	struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
 
+	blocking_notifier_chain_unregister(&ec->ec_dev->panic_notifier,
+					   &ec->debug_info->notifier_panic);
 	debugfs_remove_recursive(ec->debug_info->dir);
 	cros_ec_cleanup_console_log(ec->debug_info);
 }
-- 
2.50.1 (Apple Git-155)

Re: [PATCH] platform/chrome: cros_ec_debugfs: unregister panic notifier on remove

[Tzung-Bi Shih]

On Mon, Jun 15, 2026 at 02:32:00PM +0800, Pengpeng Hou wrote:
> cros_ec_debugfs_probe() registers a panic notifier whose callback
> recovers struct cros_ec_debugfs with container_of() and can schedule or
> flush the console log work.
> 
> cros_ec_debugfs_remove() removes debugfs state and cleans up the console
> log buffer, but it leaves the notifier registered.  A later panic
> notification can therefore call back into freed debugfs state.
> 
> Unregister the panic notifier before tearing down the debugfs and log
> state.
> 
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>

For my reference,
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>