From: Joerg Roedel <joro@8bytes.org>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: iommu@lists.linux-foundation.org, robin.murphy@arm.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/dma: Fix calculation overflow in __finalise_sg()
Date: Mon, 1 Jul 2019 14:21:59 +0200 [thread overview]
Message-ID: <20190701122158.GE8166@8bytes.org> (raw)
In-Reply-To: <20190622043814.5003-1-nicoleotsuka@gmail.com>
On Fri, Jun 21, 2019 at 09:38:14PM -0700, Nicolin Chen wrote:
> The max_len is a u32 type variable so the calculation on the
> left hand of the last if-condition will potentially overflow
> when a cur_len gets closer to UINT_MAX -- note that there're
> drivers setting max_seg_size to UINT_MAX:
> drivers/dma/dw-edma/dw-edma-core.c:745:
> dma_set_max_seg_size(dma->dev, U32_MAX);
> drivers/dma/dma-axi-dmac.c:871:
> dma_set_max_seg_size(&pdev->dev, UINT_MAX);
> drivers/mmc/host/renesas_sdhi_internal_dmac.c:338:
> dma_set_max_seg_size(dev, 0xffffffff);
> drivers/nvme/host/pci.c:2520:
> dma_set_max_seg_size(dev->dev, 0xffffffff);
>
> So this patch just casts the cur_len in the calculation to a
> size_t type to fix the overflow issue, as it's not necessary
> to change the type of cur_len after all.
>
> Fixes: 809eac54cdd6 ("iommu/dma: Implement scatterlist segment merging")
> Cc: stable@vger.kernel.org
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Looks good to me, but I let Robin take a look too before I apply it,
Robin?
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next prev parent reply other threads:[~2019-07-01 12:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-22 4:38 [PATCH] iommu/dma: Fix calculation overflow in __finalise_sg() Nicolin Chen
2019-07-01 12:21 ` Joerg Roedel [this message]
2019-07-01 12:39 ` Robin Murphy
2019-07-01 21:50 ` Nicolin Chen
2019-07-02 10:40 ` Robin Murphy
2019-07-02 21:04 ` Nicolin Chen
2019-07-25 17:36 ` Nicolin Chen
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