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SubjectRE: [EXT] Re: [PATCH] crypto: octeontx2: fix potential null pointer access
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>> >> @@ -731,7 +732,13 @@ static int otx2_cptpf_probe(struct pci_dev *pdev,
>> >> pci_set_drvdata(pdev, cptpf);
>> >> cptpf->pdev = pdev;
>> >>
>> >> - cptpf->reg_base = pcim_iomap_table(pdev)[PCI_PF_REG_BAR_NUM];
>> >> + iomap = pcim_iomap_table(pdev);
>> >
>> >I don't know if a check is required here or not... The comments to
>> >pcim_iomap_table() say it is, "guaranteed to succeed once allocated."
>> >
>>
>> Will keep the check just to be safe, as allocation/kmalloc could fail.
>
>No, it cannot fail.
>
>I don't care if you add pointless NULL checks to make the static checker
>happy, but it's important to understand what the code is doing.
>
>drivers/crypto/marvell/octeontx2/otx2_cptpf_main.c
> 701 static int otx2_cptpf_probe(struct pci_dev *pdev,
> 702 const struct pci_device_id *ent)
> 703 {
> 704 struct device *dev = &pdev->dev;
> 705 struct otx2_cptpf_dev *cptpf;
> 706 int err;
> 707
> 708 cptpf = devm_kzalloc(dev, sizeof(*cptpf), GFP_KERNEL);
> 709 if (!cptpf)
> 710 return -ENOMEM;
> 711
> 712 err = pcim_enable_device(pdev);
> 713 if (err) {
> 714 dev_err(dev, "Failed to enable PCI device\n");
> 715 goto clear_drvdata;
> 716 }
> 717
> 718 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
> 719 if (err) {
> 720 dev_err(dev, "Unable to get usable DMA configuration\n");
> 721 goto clear_drvdata;
> 722 }
> 723 /* Map PF's configuration registers */
> 724 err = pcim_iomap_regions_request_all(pdev, 1 <<
>PCI_PF_REG_BAR_NUM,
> 725 OTX2_CPT_DRV_NAME);
>
>The pcim_iomap_table() is allocated here inside the pcim_iomap_regions()
>function.
>
> 726 if (err) {
> 727 dev_err(dev, "Couldn't get PCI resources 0x%x\n", err);
> 728 goto clear_drvdata;
> 729 }
> 730 pci_set_master(pdev);
> 731 pci_set_drvdata(pdev, cptpf);
> 732 cptpf->pdev = pdev;
> 733
> 734 cptpf->reg_base = pcim_iomap_table(pdev)[PCI_PF_REG_BAR_NUM];
>
>It cannot fail here. It is not allocated here. We just look it up and
>use it.
>
> 735
> 736 /* Check if AF driver is up, otherwise defer probe */
> 737 err = cpt_is_pf_usable(cptpf);
> 738 if (err)
> 739 goto clear_drvdata;
>

Thanks Dan, I got it now. I will remove the check from v2.

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