linux-kernel - Re: [syzbot] WARNING in dma_map

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: <YpWrfnkipIzoWEcd@infradead.org>
Date:   Mon, 30 May 2022 22:45:34 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Dan Carpenter <dan.carpenter@...cle.com>
Cc:     Hillf Danton <hdanton@...a.com>,
        syzbot <syzbot+3ba551855046ba3b3806@...kaller.appspotmail.com>,
        linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] WARNING in dma_map_sgtable (2)

Someohow only the reply from Dan got delivered to me, not the mail
from Hillf he is replying to, so I'm abusing that to reply to the
previous mail..

On Mon, May 30, 2022 at 06:10:44PM +0300, Dan Carpenter wrote:
> > --- y/drivers/dma-buf/udmabuf.c
> > +++ u/drivers/dma-buf/udmabuf.c
> > @@ -273,6 +273,14 @@ static long udmabuf_create(struct miscde
> >  	if (IS_ERR(buf)) {
> >  		ret = PTR_ERR(buf);
> >  		goto err;
> > +	} else {
> > +		struct device *dev = ubuf->device->this_device;
> > +
> > +		if (!dev->dma_mask) {
> > +			ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
> > +			if (ret)
> > +				goto err;
> > +		}
> >  	}

This is compeltely broken.  If the underlying device is ot DMA capable and
we can't just set a random mask and still allow DMA mappings.