Re: [PATCH] Fix suspicious RCU usage warning

From: Madhuparna Bhowmik
Date: Thu May 14 2020 - 03:04:21 EST


On Wed, May 13, 2020 at 12:00:10PM -0700, David Miller wrote:
> From: madhuparnabhowmik10@xxxxxxxxx
> Date: Wed, 13 May 2020 11:46:10 +0530
>
> > From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
> >
> > This patch fixes the following warning:
> >
> > =============================
> > WARNING: suspicious RCU usage
> > 5.7.0-rc4-next-20200507-syzkaller #0 Not tainted
> > -----------------------------
> > net/ipv6/ip6mr.c:124 RCU-list traversed in non-reader section!!
> >
> > ipmr_new_table() returns an existing table, but there is no table at
> > init. Therefore the condition: either holding rtnl or the list is empty
> > is used.
> >
> > Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
> > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
> >
> > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
>
> Please only provide one signoff line.
>
> Please provide a proper Fixes: tag for this bug fix.
>
> And finally, please make your Subject line more appropriate. It must
> first state the target tree inside of the "[PATCH]" area, the two choices
> are "[PATCH net]" and "[PATCH net-next]" and it depends upon which tree
> this patch is targetting.
>
> Then your Subject line should also be more descriptive about exactly the
> subsystem and area the change is being made to, for this change for
> example you could use something like:
>
> ipv6: Fix suspicious RCU usage warning in ip6mr.
>
> Also, obviously, there are also syzkaller tags you can add to the
> commit message as well.
Sorry for this malformed patch, I have sent a patch with all these
corrections.

Thank you,
Madhuparna