From ac41b05d15db3134e839148290d67415ee0bdb58 Mon Sep 17 00:00:00 2001 From: Manush Prajwal Date: Sun, 6 Sep 2026 16:44:09 +0530 Subject: [PATCH] rtc: mpfs: fix unchecked devm_clk_get() error pointer in probe() devm_clk_get(&pdev->dev, "rtcref")'s return value was passed straight into clk_get_rate() without checking it for an error first, unlike the "rtc" clock a few lines above which is correctly checked with IS_ERR(). clk_get_rate() only guards against a NULL clk, not an error pointer: if (!clk) return 0; ... rate = clk_core_get_rate_recalc(clk->core); so if devm_clk_get() ever returns an error pointer here (for example ERR_PTR(-EPROBE_DEFER), which is the normal, expected outcome if the clkcfg clock-provider this RTC depends on has not registered its clocks yet by the time this driver probes), clk_get_rate() dereferences that error pointer instead of returning 0, crashing instead of letting probe defer. Capture the clock in the existing 'clk' local and check it with IS_ERR() before calling clk_get_rate(), matching the handling already used for the "rtc" clock in this same function. Signed-off-by: Manush Prajwal Fixes: 0b31d703598d ("rtc: Add driver for Microchip PolarFire SoC") Reviewed-by: Conor Dooley Link: https://patch.msgid.link/6a9d4b02.7d74b517.206c4c.75f8@mx.google.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-mpfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-mpfs.c b/drivers/rtc/rtc-mpfs.c index ece6de4a6adb..60596b0ea9d8 100644 --- a/drivers/rtc/rtc-mpfs.c +++ b/drivers/rtc/rtc-mpfs.c @@ -256,8 +256,12 @@ static int mpfs_rtc_probe(struct platform_device *pdev) return ret; } + clk = devm_clk_get(&pdev->dev, "rtcref"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + /* prescaler hardware adds 1 to reg value */ - prescaler = clk_get_rate(devm_clk_get(&pdev->dev, "rtcref")) - 1; + prescaler = clk_get_rate(clk) - 1; if (prescaler > MAX_PRESCALER_COUNT) { dev_dbg(&pdev->dev, "invalid prescaler %lu\n", prescaler); return -EINVAL;