Re: [PATCH] netlink: Don't shift with UB on nlk->ngroups

Re: [PATCH] netlink: Don't shift with UB on nlk->ngroups

[David Miller]

From: Dmitry Safonov <dima@arista.com>
Date: Mon, 30 Jul 2018 18:32:36 +0100

> On i386 nlk->ngroups might be 32 or 0. Which leads to UB, resulting in
> hang during boot.
> Check for 0 ngroups and use (unsigned long long) as a type to shift.
> 
> Fixes: commit 7acf9d4237c46894e0fa0492dd96314a41742e84 ("netlink: Do not
> subscribe to non-existent groups").

Please, in the future, format your Fixes: tag correctly.  No need
to say the work "commit", please do not chop up the line no matter
how long it is, and please provide 12 digits of SHA1_ID value, rather
than the whole thing.

> Reported-by: kernel test robot <rong.a.chen@intel.com>
> Signed-off-by: Dmitry Safonov <dima@arista.com>

Applied, thank you.

Re: [PATCH] netlink: Don't shift with UB on nlk->ngroups

[Dmitry Safonov]

On Mon, 2018-07-30 at 12:43 -0700, David Miller wrote:
> From: Dmitry Safonov <dima@arista.com>
> Date: Mon, 30 Jul 2018 18:32:36 +0100
> 
> > On i386 nlk->ngroups might be 32 or 0. Which leads to UB, resulting
> in
> > hang during boot.
> > Check for 0 ngroups and use (unsigned long long) as a type to
> shift.
> > 
> > Fixes: commit 7acf9d4237c46894e0fa0492dd96314a41742e84 ("netlink:
> Do not
> > subscribe to non-existent groups").
> 
> Please, in the future, format your Fixes: tag correctly.  No need
> to say the work "commit", please do not chop up the line no matter
> how long it is, and please provide 12 digits of SHA1_ID value, rather
> than the whole thing.

Oh, yeah, I have this in .gitconfig:
[core]
        abbrev = 12

But I was formatting this not on my laptop and have managed to mislook.
Sorry about "commit" and the breakage.

> > Reported-by: kernel test robot <rong.a.chen@intel.com>
> > Signed-off-by: Dmitry Safonov <dima@arista.com>
> 
> Applied, thank you.

Thank you.