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

[Subhash Jadavani]

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);
> >
> > --
> > The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> > a Linux Foundation Collaborative Project
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