From: Krzysztof Kozlowski <krzk@xxxxxxxxxx> commit 4561560dfb4f847a0b327d48bdd1f45bf1b6261f upstream. If regmap_read() fails, the product_id local variable will contain random value from the stack. Do not try to parse such value and fail the ASV driver probe. Fixes: 5ea428595cc5 ("soc: samsung: Add Exynos Adaptive Supply Voltage driver") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> Reviewed-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20201207190517.262051-3-krzk@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/soc/samsung/exynos-asv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/soc/samsung/exynos-asv.c +++ b/drivers/soc/samsung/exynos-asv.c @@ -129,7 +129,13 @@ static int exynos_asv_probe(struct platf return PTR_ERR(asv->chipid_regmap); } - regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID, &product_id); + ret = regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID, + &product_id); + if (ret < 0) { + dev_err(&pdev->dev, "Cannot read revision from ChipID: %d\n", + ret); + return -ENODEV; + } switch (product_id & EXYNOS_MASK) { case 0xE5422000: