07.03.2024 13:57, Ulf Hansson wrote:
On Thu, 7 Mar 2024 at 09:53, Aleksandr Mishin <amishin@xxxxxxxxxx> 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@xxxxxxxxxx>
---
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
At the same time there are few checks such as "if (host->slot)" in
dw_mci_runtime_resume() and commit
4a835afd808a3dbbac44bb399a902b822dc7445c message contains: "we
previously assumed 'host->slot' could be null, null pointer judgment
should be added" and replaces "if (host->slot->mmc->pm_flags &
MMC_PM_KEEP_POWER)" with "if (host->slot && host->slot->mmc->pm_flags &
MMC_PM_KEEP_POWER)"
So where is the truth?
--
Kind regadrds
Aleksandr
