mmc: sunxi: Prevent against null dereference for vmmc (424feb59) · Commits · 戴 / test

VMMC is an optional regulator, which means that mmc_regulator_get_supply will only return an error in case of a deferred probe, but not when the regulator is not set in the DT. However, the sunxi driver assumes that VMMC is always there, and doesn't check the value of the regulator pointer before using it, which obviously leads to a (close to) null pointer dereference. Add proper checks to prevent that. Signed-off-by:

Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by:

Chen-Yu Tsai <wens@csie.org> Signed-off-by:

Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sunxi-mmc.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -822,10 +822,13 @@ static void sunxi_mmc_set_ios(struct mmc_host mmc, struct mmc_ios ios)
		break;

		case MMC_POWER_UP:
		host->ferror = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
		if (!IS_ERR(mmc->supply.vmmc)) {
		host->ferror = mmc_regulator_set_ocr(mmc,
		mmc->supply.vmmc,
		ios->vdd);
		if (host->ferror)
		return;
		}

		if (!IS_ERR(mmc->supply.vqmmc)) {
		host->ferror = regulator_enable(mmc->supply.vqmmc);
		@@ -847,7 +850,9 @@ static void sunxi_mmc_set_ios(struct mmc_host mmc, struct mmc_ios ios)
		case MMC_POWER_OFF:
		dev_dbg(mmc_dev(mmc), "power off!\n");
		sunxi_mmc_reset_host(host);
		if (!IS_ERR(mmc->supply.vmmc))
		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);

		if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled)
		regulator_disable(mmc->supply.vqmmc);
		host->vqmmc_enabled = false;

Admin message