From e6a0e7a49d83e4fa4e1db68d74f99282eb97aa49 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Tue, 14 Jul 2026 13:56:28 +0100 Subject: [PATCH] firmware: arm_scmi: Protect device request lookup with RCU The SCMI device request notifier looks up protocol OF nodes from the active_protocols IDR. The IDR lookup can run concurrently with protocol activation while probe is still registering protocols and creating their SCMI devices. Wrap the lookup in an RCU read-side critical section as required by the IDR API for lockless readers. Fixes: 53b8c25df708 ("firmware: arm_scmi: Add common notifier helpers") Reported-by: Sashiko Link: https://patch.msgid.link/20260714-scmi_core_fixes-v6-9-3afe499d46e3@kernel.org Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index f607557c04ad..a2871dca24dc 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -2958,7 +2959,9 @@ static int scmi_device_request_notifier(struct notifier_block *nb, struct scmi_device_id *id_table = data; struct scmi_info *info = req_nb_to_scmi_info(nb); + rcu_read_lock(); np = idr_find(&info->active_protocols, id_table->protocol_id); + rcu_read_unlock(); if (!np) return NOTIFY_DONE;