From e9076ffbcaed5da6c182b144ef9f6e24554af268 Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Wed, 17 Aug 2022 18:27:29 +0100
Subject: [PATCH] firmware: arm_scmi: Harden accesses to the reset domains
Git-commit: e9076ffbcaed5da6c182b144ef9f6e24554af268
Patch-mainline: v6.0-rc7
References: git-fixes

Accessing reset domains descriptors by the index upon the SCMI drivers
requests through the SCMI reset operations interface can potentially
lead to out-of-bound violations if the SCMI driver misbehave.

Add an internal consistency check before any such domains descriptors
accesses.

Link: https://lore.kernel.org/r/20220817172731.1185305-5-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/firmware/arm_scmi/reset.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index 673f3eb498f4..b0494165b1cb 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -166,8 +166,12 @@ static int scmi_domain_reset(const struct scmi_protocol_handle *ph, u32 domain,
 	struct scmi_xfer *t;
 	struct scmi_msg_reset_domain_reset *dom;
 	struct scmi_reset_info *pi = ph->get_priv(ph);
-	struct reset_dom_info *rdom = pi->dom_info + domain;
+	struct reset_dom_info *rdom;
 
+	if (domain >= pi->num_domains)
+		return -EINVAL;
+
+	rdom = pi->dom_info + domain;
 	if (rdom->async_reset)
 		flags |= ASYNCHRONOUS_RESET;
 
-- 
2.35.3