ipmi: ssif_bmc: cancel response timer on remove

The response timer can stay armed across device teardown. If it fires after
remove, the callback dereferences the SSIF context and the i2c client after
teardown has started.

Cancel the timer in remove so the callback cannot run after the device is
unregistered.

Signed-off-by: Jian Zhang <zhangjian.3032@bytedance.com>
Message-ID: <20260403090603.3988423-1-zhangjian.3032@bytedance.com>
Signed-off-by: Corey Minyard <corey@minyard.net>

Author: zhangjian3032

drivers/char/ipmi/ssif_bmc.c

@@ -843,6 +843,7 @@ static void ssif_bmc_remove(struct i2c_client *client)
 {
 	struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client);
 
+	timer_delete_sync(&ssif_bmc->response_timer);
 	i2c_slave_unregister(client);
 	misc_deregister(&ssif_bmc->miscdev);
 }