Re: [PATCH net v2] ipv6: Fix suspicious RCU usage warning in ip6mr

From: David Miller
Date: Sat May 16 2020 - 16:43:07 EST


From: madhuparnabhowmik10@xxxxxxxxx
Date: Sat, 16 May 2020 13:15:15 +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.
>
> Fixes: d1db275dd3f6e ("ipv6: ip6mr: support multiple tables")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>

Applied and queued up for -stable, thanks.