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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Wed, 03 Apr 2024 06:10:57 +0300
Subject: [PATCH v2 1/2] soc: qcom: pmic_glink: don't traverse clients list
 without a lock
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Message-Id: <20240403-pmic-glink-fix-clients-v2-1-aed4e02baacc@linaro.org>
References: <20240403-pmic-glink-fix-clients-v2-0-aed4e02baacc@linaro.org>
In-Reply-To: <20240403-pmic-glink-fix-clients-v2-0-aed4e02baacc@linaro.org>
To: Bjorn Andersson <andersson@kernel.org>, 
 Konrad Dybcio <konrad.dybcio@linaro.org>, 
 Neil Armstrong <neil.armstrong@linaro.org>
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Take the client_lock before traversing the clients list at the
pmic_glink_state_notify_clients() function. This is required to keep the
list traversal safe from concurrent modification.

Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/soc/qcom/pmic_glink.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
index f913e9bd57ed..2b2cdf479654 100644
--- a/drivers/soc/qcom/pmic_glink.c
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -115,10 +115,12 @@ static int pmic_glink_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 
 	hdr = data;
 
+	mutex_lock(&pg->client_lock);
 	list_for_each_entry(client, &pg->clients, node) {
 		if (client->id == le32_to_cpu(hdr->owner))
 			client->cb(data, len, client->priv);
 	}
+	mutex_unlock(&pg->client_lock);
 
 	return 0;
 }
@@ -168,8 +170,10 @@ static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
 	}
 
 	if (new_state != pg->client_state) {
+		mutex_lock(&pg->client_lock);
 		list_for_each_entry(client, &pg->clients, node)
 			client->pdr_notify(client->priv, new_state);
+		mutex_unlock(&pg->client_lock);
 		pg->client_state = new_state;
 	}
 }

-- 
2.39.2