From 424feb59d87828a7569174becc17f9b0905a304f Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Wed, 19 Oct 2016 15:33:04 +0200 Subject: [PATCH] mmc: sunxi: Prevent against null dereference for vmmc 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 Acked-by: Chen-Yu Tsai Signed-off-by: Ulf Hansson --- drivers/mmc/host/sunxi-mmc.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c index c0a5c67..b1d1303 100644 --- a/drivers/mmc/host/sunxi-mmc.c +++ b/drivers/mmc/host/sunxi-mmc.c @@ -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, - ios->vdd); - if (host->ferror) - return; + 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); - mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0); + 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; -- 2.7.4