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From:   Fei Shao <fshao@chromium.org>
To:     Jassi Brar <jaswinder.singh@linaro.org>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Tzung-Bi Shih <tzungbi@google.com>,
        Fei Shao <fshao@chromium.org>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        "jason-jh.lin" <jason-jh.lin@mediatek.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mediatek@lists.infradead.org
Subject: [PATCH v2 1/2] mailbox: mtk-cmdq: Validate alias_id on probe
Date:   Thu, 14 Oct 2021 20:03:51 +0800
Message-Id: <20211014120352.1506321-2-fshao@chromium.org>
In-Reply-To: <20211014120352.1506321-1-fshao@chromium.org>
References: <20211014120352.1506321-1-fshao@chromium.org>
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of_alias_get_id() may return -ENODEV which leads to illegal access to
the cmdq->clocks array.
Adding a check over alias_id to prevent the unexpected behavior.

Fixes: 85dfdbfc13ea ("mailbox: cmdq: add multi-gce clocks support for
mt8195")
Signed-off-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@google.com>
---

Changes in v2:
- Add Reviewed-by tag

 drivers/mailbox/mtk-cmdq-mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 64175a893312..f3e52dddd422 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -573,7 +573,7 @@ static int cmdq_probe(struct platform_device *pdev)
 			char clk_id[8];
 
 			alias_id = of_alias_get_id(node, clk_name);
-			if (alias_id < cmdq->gce_num) {
+			if (alias_id >= 0 && alias_id < cmdq->gce_num) {
 				snprintf(clk_id, sizeof(clk_id), "%s%d", clk_name, alias_id);
 				cmdq->clocks[alias_id].id = clk_id;
 				cmdq->clocks[alias_id].clk = of_clk_get(node, 0);
-- 
2.33.0.882.g93a45727a2-goog