linux-kernel - RE: [PATCH] regmap: irq: Fix possible ZERO_SIZE

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <a9148f4a1b3e4bab928365e455edf1cc@BY2PR03MB505.namprd03.prod.outlook.com>
Date:	Mon, 19 May 2014 23:51:26 +0000
From:	"Li.Xiubo@...escale.com" <Li.Xiubo@...escale.com>
To:	Mark Brown <broonie@...nel.org>
CC:	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] regmap: irq: Fix possible ZERO_SIZE_PTR pointer
 dereferencing error.

> Subject: Re: [PATCH] regmap: irq: Fix possible ZERO_SIZE_PTR pointer
> dereferencing error.
> 
> On Mon, May 19, 2014 at 03:13:45PM +0800, Xiubo Li wrote:
> > Since we cannot make sure the 'chip->num_regs' will always be none zero
> > from the users, and then if 'chip->num_regs' equals to zero by mistake
> > or other reasons, the kzalloc() will return ZERO_SIZE_PTR, which equals
> > to ((void *)16).
> >
> > So this patch fix this with just checking the 'chip->num_regs' before
> > calling kzalloc().
> 
> Where is the actual dereference that's being protected against here?
> 

Such as:
        d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
                              GFP_KERNEL);
        if (!d->mask_buf)
                goto err_alloc;

And then:
        d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;



> > This also sorts the header files in alphabetical order at the same time.
> 
> No, don't do things like this.  It just makes things harder to review.

Okay, I'll follow your advice.

Thanks,

BRs
Xiubo

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/