linux-kernel - Re: [PATCH] dma-mapping: Protect dma_addressing_limited against NULL dma

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20190722114303.GA32052@lst.de>
Date:   Mon, 22 Jul 2019 13:43:03 +0200
From:   Christoph Hellwig <hch@....de>
To:     Eric Auger <eric.auger@...hat.com>
Cc:     eric.auger.pro@...il.com, hch@....de, m.szyprowski@...sung.com,
        robin.murphy@....com, iommu@...ts.linux-foundation.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] dma-mapping: Protect dma_addressing_limited against
 NULL dma_mask

I posted a fix that takes care of this in SCSI this morning:

https://marc.info/?l=linux-scsi&m=156378725427719&w=2

I suspect for virtio-blk we should do the same.

>  static inline bool dma_addressing_limited(struct device *dev)
>  {
> -	return min_not_zero(*dev->dma_mask, dev->bus_dma_mask) <
> -		dma_get_required_mask(dev);
> +	return dev->dma_mask ? min_not_zero(*dev->dma_mask, dev->bus_dma_mask) <
> +		dma_get_required_mask(dev) : false;

But to be on the safe side we could still do an early return here,
but it should have a WARN_ON_ONCE.