[lvc-project] [PATCH] mmc: dw_mmc: Fix potential null pointer risk

Thu Mar 7 13:57:16 MSK 2024

On Thu, 7 Mar 2024 at 09:53, Aleksandr Mishin <amishin at t-argos.ru> wrote:
>> In dw_mci_runtime_resume() 'host->slot' could be null, but check is not cover all corresponding code.
> Fix this bug by changing check place.

In fact host->slot can never be NULL in dw_mci_runtime_resume() or in
dw_mci_runtime_suspend().
A better fix would thus be to remove the redundant checks.
Kind regards
Uffe
>> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>> Fixes: 4a835afd808a (mmc: dw_mmc: Fix potential null pointer risk)
> Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
> ---
> drivers/mmc/host/dw_mmc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 829af2c98a44..a4f124452abc 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -3570,8 +3570,10 @@ int dw_mci_runtime_resume(struct device *dev)
> DW_MCI_ERROR_FLAGS);
> mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
>> + if (!host->slot)
> + goto err;
>> - if (host->slot && host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
> + if (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 */
> --
> 2.30.2
>>