From: Dan Carpenter <dan.carpenter@oracle.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] module: static checker complains about negative values
Date: Tue, 20 May 2014 08:19:58 +0000 [thread overview]
Message-ID: <20140520081957.GD15585@mwanda> (raw)
In-Reply-To: <87y4xxi5nn.fsf@rustcorp.com.au>
On Tue, May 20, 2014 at 11:16:04AM +0930, Rusty Russell wrote:
> Dan Carpenter <dan.carpenter@oracle.com> writes:
>
> > We cap "stat.size" at INT_MAX but we don't check for negative values so
> > my static checker complains. At this point, you already have control of
> > the kernel and if you start passing negative values here then you
> > deserve what happens next.
> >
> > On 64 bit systems the vmalloc() will definitely fail. On 32 bit systems
> > we truncate the upper 32 bits away so that could succeed. I haven't
> > followed it further than that.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> If vfs_getattr() returns a negative stat.size, we have worse problems.
>
> I'd rather see you sprinkle assertions like that into the code, so we
> can make sure that can't happen for any fs's getattr().
Yeah. I was lazy. Sorry. I can just hand edit my database to say that
i_size_read() returns a reasonable number...
regards,
dan carpenter
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] module: static checker complains about negative values
Date: Tue, 20 May 2014 11:19:58 +0300 [thread overview]
Message-ID: <20140520081957.GD15585@mwanda> (raw)
In-Reply-To: <87y4xxi5nn.fsf@rustcorp.com.au>
On Tue, May 20, 2014 at 11:16:04AM +0930, Rusty Russell wrote:
> Dan Carpenter <dan.carpenter@oracle.com> writes:
>
> > We cap "stat.size" at INT_MAX but we don't check for negative values so
> > my static checker complains. At this point, you already have control of
> > the kernel and if you start passing negative values here then you
> > deserve what happens next.
> >
> > On 64 bit systems the vmalloc() will definitely fail. On 32 bit systems
> > we truncate the upper 32 bits away so that could succeed. I haven't
> > followed it further than that.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> If vfs_getattr() returns a negative stat.size, we have worse problems.
>
> I'd rather see you sprinkle assertions like that into the code, so we
> can make sure that can't happen for any fs's getattr().
Yeah. I was lazy. Sorry. I can just hand edit my database to say that
i_size_read() returns a reasonable number...
regards,
dan carpenter
next prev parent reply other threads:[~2014-05-20 8:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-19 20:36 [patch] module: static checker complains about negative values Dan Carpenter
2014-05-19 20:36 ` Dan Carpenter
2014-05-20 1:46 ` Rusty Russell
2014-05-20 1:58 ` Rusty Russell
2014-05-20 8:19 ` Dan Carpenter [this message]
2014-05-20 8:19 ` Dan Carpenter
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