On Wed, 2014-01-29 at 09:47 +0100, Andre Naujoks wrote:

On 29.01.2014 08:46, schrieb David Miller:

quoted

From: Andre Naujoks <redacted>
Date: Wed, 29 Jan 2014 08:40:03 +0100

quoted

Even if this is a bug in the CAN BCM implementation. Your "fix" just
enabled a user space application to shut down any machine with a kernel
containing the BUG_ON patch.

Rather, he detected a potential stray pointer reference to freed data
that was caused by the CAN code which would difficult if not
impossible to detect otherwise.

That's even more dangerous, and you should be thanking him.

"potential" is the keyword here. But its a definite kernel crash as it
is right now with a standard use case for the BCM.

Don't get me wrong. If there are bugs in the code, they should be fixed,
but I don't think breaking a working (even if flawed) part of the kernel
is the right thing to do here.

Shall I remember you this patch was suggested by David Miller, our
beloved network maintainer ?

Really this is quite silly, I'll tell you.

I can send a patch to mark CAN as BROKEN if you want, or you can send an
appropriate patch.

Your resistance is futile.