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From:   "Sriram Dash" <sriram.dash@samsung.com>
To:     "'Shradha Todi'" <shradha.t@samsung.com>, <kishon@ti.com>
Cc:     <lorenzo.pieralisi@arm.com>, <bhelgaas@google.com>,
        <pankaj.dubey@samsung.com>, <linux-pci@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
In-Reply-To: <20200311102852.5207-1-shradha.t@samsung.com>
Subject: RE: [PATCH] PCI: endpoint: Fix NULL pointer dereference for
 ->get_features()
Date:   Thu, 19 Mar 2020 19:06:01 +0530
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References: <CGME20200311103443epcas5p2e97b8f3a8e52dc6f02eb551e0c97f132@epcas5p2.samsung.com>
        <20200311102852.5207-1-shradha.t@samsung.com>
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> From: Shradha Todi <shradha.t=40samsung.com>
> Subject: =5BPATCH=5D PCI: endpoint: Fix NULL pointer dereference for -
> >get_features()
>=20
> get_features ops of pci_epc_ops may return NULL, causing NULL pointer
> dereference in pci_epf_test_bind function. Let us add a check for
> pci_epc_feature pointer in pci_epf_test_bind before we access it to avoid=
 any
> such NULL pointer dereference and return -ENOTSUPP in case pci_epc_featur=
e
> is not found.
>=20
> Reviewed-by: Pankaj Dubey <pankaj.dubey=40samsung.com>
> Signed-off-by: Sriram Dash <sriram.dash=40samsung.com>
> Signed-off-by: Shradha Todi <shradha.t=40samsung.com>
> ---

Hi Kishon,

Any update on this?


>  drivers/pci/endpoint/functions/pci-epf-test.c =7C 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>=20
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c
> b/drivers/pci/endpoint/functions/pci-epf-test.c
> index c9121b1b9fa9..af4537a487bf 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> =40=40 -510,14 +510,17 =40=40 static int pci_epf_test_bind(struct pci_epf=
 *epf)
>  		return -EINVAL;
>=20
>  	epc_features =3D pci_epc_get_features(epc, epf->func_no);
> -	if (epc_features) =7B
> -		linkup_notifier =3D epc_features->linkup_notifier;
> -		msix_capable =3D epc_features->msix_capable;
> -		msi_capable =3D epc_features->msi_capable;
> -		test_reg_bar =3D pci_epc_get_first_free_bar(epc_features);
> -		pci_epf_configure_bar(epf, epc_features);
> +	if (=21epc_features) =7B
> +		dev_err(dev, =22epc_features not implemented=5Cn=22);
> +		return -ENOTSUPP;
>  	=7D
>=20
> +	linkup_notifier =3D epc_features->linkup_notifier;
> +	msix_capable =3D epc_features->msix_capable;
> +	msi_capable =3D epc_features->msi_capable;
> +	test_reg_bar =3D pci_epc_get_first_free_bar(epc_features);
> +	pci_epf_configure_bar(epf, epc_features);
> +
>  	epf_test->test_reg_bar =3D test_reg_bar;
>  	epf_test->epc_features =3D epc_features;
>=20
> --
> 2.17.1