In dw_mci_runtime_resume(), there is an if statement on line 3420 to check whether host->slot is NULL: if (host->slot && ...) When host->slot is NULL, it is used on line 3458: if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER) and on line 3462: dw_mci_setup_bus(host->slot, true); struct dw_mci *host = slot->host; Thus, possible null-pointer dereferences may occur. To fix these bugs, host->slot is checked before being used. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> --- drivers/mmc/host/dw_mmc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index faaaf52a46d2..91bd6c3ccf50 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -3455,11 +3455,12 @@ int dw_mci_runtime_resume(struct device *dev) mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE); - if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER) + if (host->slot && (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)) dw_mci_set_ios(host->slot->mmc, &host->slot->mmc->ios); /* Force setup bus to guarantee available clock output */ - dw_mci_setup_bus(host->slot, true); + if (host->slot) + dw_mci_setup_bus(host->slot, true); /* Now that slots are all setup, we can enable card detect */ dw_mci_enable_cd(host); -- 2.17.0