From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: idosch@idosch.org, hkallweit1@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCH net] ipv6: addrconf: break critical section in addrconf_verify_rtnl()
Date: Mon, 29 Jan 2018 14:24:31 -0500 (EST) [thread overview]
Message-ID: <20180129.142431.368786370257576620.davem@davemloft.net> (raw)
In-Reply-To: <1517011843.3715.68.camel@gmail.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 26 Jan 2018 16:10:43 -0800
> From: Eric Dumazet <edumazet@google.com>
>
> Heiner reported a lockdep splat [1]
>
> This is caused by attempting GFP_KERNEL allocation while RCU lock is
> held and BH blocked.
>
> We believe that addrconf_verify_rtnl() could run for a long period,
> so instead of using GFP_ATOMIC here as Ido suggested, we should break
> the critical section and restart it after the allocation.
>
>
> [1]
...
> Fixes: f3d9832e56c4 ("ipv6: addrconf: cleanup locking in ipv6_add_addr")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Applied and queued up for v4.15 -stable, thanks.
next prev parent reply other threads:[~2018-01-29 19:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-20 11:57 ipv6_addrconf: WARNING about suspicious RCU usage Heiner Kallweit
2018-01-20 13:37 ` Ido Schimmel
2018-01-20 18:49 ` Eric Dumazet
2018-01-20 19:19 ` Ido Schimmel
2018-01-20 19:48 ` Heiner Kallweit
2018-01-21 21:22 ` Heiner Kallweit
2018-01-23 18:01 ` Ido Schimmel
2018-01-23 18:43 ` Eric Dumazet
2018-01-27 0:10 ` [PATCH net] ipv6: addrconf: break critical section in addrconf_verify_rtnl() Eric Dumazet
2018-01-27 8:52 ` Ido Schimmel
2018-01-29 19:24 ` David Miller [this message]
2018-01-26 22:15 ` ipv6_addrconf: WARNING about suspicious RCU usage Heiner Kallweit
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