Re: [PATCH] ufs: qcom: Properly clear hba priv on failure

From: Subhash Jadavani
Date: Mon Nov 21 2016 - 13:33:02 EST


On 2016-11-19 22:15, Bjorn Andersson wrote:
On Sat 19 Nov 12:30 PST 2016, Subhash Jadavani wrote:

On 2016-11-18 12:55, Bjorn Andersson wrote:
>In the case where we fail to acquire the phy the hba priv will be set
>already, so during cleanup ufs_qcom_setup_clocks() will dereference the
>now free, but still "valid looking" pointer "host".

host (ufs_qcom_host) was allocated with devm_kzalloc() so i am not sure why
it would be freed up before probe() returns failure.


Sorry, I missed the fact that the devm_kfree() was dropped, the actual
problem still remains, although it no longer results in a panic.

Agreed.


As ufs_qcom_init() returns from not having found the phy it the variant
data will be a zero-initialized object. The error path of
ufshcd_hba_init() will then take us through ufs_qcom_setup_clocks(),
which will pass the check for a NULL variant data and use the
uninitialized host object.

Yes, Make sense.


I can update the commit message to reflect the new state of things.

Your new patch set looks good, will add my ack.


Regards,
Bjorn

>Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
>---
> drivers/scsi/ufs/ufs-qcom.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>index d345434b084f..7bd88ffee47a 100644
>--- a/drivers/scsi/ufs/ufs-qcom.c
>+++ b/drivers/scsi/ufs/ufs-qcom.c
>@@ -1197,7 +1197,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> if (IS_ERR(host->generic_phy)) {
> err = PTR_ERR(host->generic_phy);
> dev_err(dev, "%s: PHY get failed %d\n", __func__, err);
>- goto out;
>+ goto out_host_free;
> }
>
> err = ufs_qcom_bus_register(host);

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