[PATCH 5.15.y 5/5] usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove

[Sasha Levin <sashal@kernel.org>]

From: Fan Wu <fanwu01@zju.edu.cn>

[ Upstream commit 1f0bdc2884b67de337215079bba166df0cdf4ac5 ]

The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(),
which on a connector-change event calls ucsi_connector_change() and
schedules connector work.  In ucsi_ccg_remove(), ucsi_destroy() frees
uc->ucsi (kfree) before free_irq() is called, so a handler invocation
already in flight may access the freed object after ucsi_destroy().

  CPU 0 (remove)            | CPU 1 (threaded IRQ)
    ucsi_destroy(uc->ucsi)  |   ccg_irq_handler()
      kfree(ucsi) // FREE   |     ucsi_notify_common(uc->ucsi) // USE

Move free_irq() before ucsi_destroy() in the remove path.  It is kept
after ucsi_unregister(): ucsi_unregister() cancels connector work whose
handler issues GET_CONNECTOR_STATUS through ucsi_send_command_common(),
which waits for a completion that is signalled from the IRQ handler, so
the IRQ must stay active until that work has been cancelled.

The probe error path already orders free_irq() before ucsi_destroy().

This bug was found by static analysis.

Fixes: e32fd989ac1c ("usb: typec: ucsi: ccg: Move to the new API")
Cc: stable <stable@kernel.org>
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260616132011.103279-1-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/typec/ucsi/ucsi_ccg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
index 68a693d92dd05a..8d69bc5bff20a9 100644
--- a/drivers/usb/typec/ucsi/ucsi_ccg.c
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -1418,8 +1418,8 @@ static int ucsi_ccg_remove(struct i2c_client *client)
 	cancel_work_sync(&uc->work);
 	pm_runtime_disable(uc->dev);
 	ucsi_unregister(uc->ucsi);
-	ucsi_destroy(uc->ucsi);
 	free_irq(uc->irq, uc);
+	ucsi_destroy(uc->ucsi);
 
 	return 0;
 }
-- 
2.53.0