Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-20 Thread Eric Dumazet
On Mon, 2017-03-20 at 10:59 +0100, Dmitry Vyukov wrote: > On Tue, Mar 14, 2017 at 5:41 PM, Cong Wang wrote: > > On Tue, Mar 14, 2017 at 7:56 AM, Eric Dumazet wrote: > >> On Tue, Mar 14, 2017 at 7:46 AM, Dmitry Vyukov wrote: > >> > >>> I am confused. Lockdep has observed both of these stacks: > >

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-20 Thread Dmitry Vyukov
On Tue, Mar 14, 2017 at 5:41 PM, Cong Wang wrote: > On Tue, Mar 14, 2017 at 7:56 AM, Eric Dumazet wrote: >> On Tue, Mar 14, 2017 at 7:46 AM, Dmitry Vyukov wrote: >> >>> I am confused. Lockdep has observed both of these stacks: >>> >>>CPU0CPU1 >>>

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Cong Wang
On Tue, Mar 14, 2017 at 7:56 AM, Eric Dumazet wrote: > On Tue, Mar 14, 2017 at 7:46 AM, Dmitry Vyukov wrote: > >> I am confused. Lockdep has observed both of these stacks: >> >>CPU0CPU1 >> >> lock(&(&q->lock)->rlock); >>

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Paolo Abeni
On Tue, 2017-03-14 at 08:09 -0700, Eric Dumazet wrote: > On Tue, Mar 14, 2017 at 8:03 AM, Paolo Abeni wrote: > > > I'm wondering if we really need to keep the fragment queue lock held > > while sending the icmp packet ? we hold a reference to the struct, so > > it can't be deleted, and AFAICS aft

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Eric Dumazet
On Tue, Mar 14, 2017 at 8:03 AM, Paolo Abeni wrote: > I'm wondering if we really need to keep the fragment queue lock held > while sending the icmp packet ? we hold a reference to the struct, so > it can't be deleted, and AFAICS after ipq_kill() nobody else could > access/modify that queue. > > T

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Paolo Abeni
On Tue, 2017-03-14 at 07:41 -0700, Eric Dumazet wrote: > On Tue, 2017-03-14 at 14:31 +0100, Dmitry Vyukov wrote: > > Hello, > > > > I've got the following deadlock report while running syzkaller fuzzer > > on net-next/92cd12c5ed432c5eebd2462d666772a8d8442c3b: > > > > > > [ INFO: possible circula

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Dmitry Vyukov
On Tue, Mar 14, 2017 at 3:56 PM, Eric Dumazet wrote: > On Tue, Mar 14, 2017 at 7:46 AM, Dmitry Vyukov wrote: > >> I am confused. Lockdep has observed both of these stacks: >> >>CPU0CPU1 >> >> lock(&(&q->lock)->rlock); >>

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Eric Dumazet
On Tue, Mar 14, 2017 at 7:46 AM, Dmitry Vyukov wrote: > I am confused. Lockdep has observed both of these stacks: > >CPU0CPU1 > > lock(&(&q->lock)->rlock); >lock(_xmit_ETHER#2); >

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Dmitry Vyukov
On Tue, Mar 14, 2017 at 3:41 PM, Eric Dumazet wrote: > On Tue, 2017-03-14 at 14:31 +0100, Dmitry Vyukov wrote: >> Hello, >> >> I've got the following deadlock report while running syzkaller fuzzer >> on net-next/92cd12c5ed432c5eebd2462d666772a8d8442c3b: >> >> >> [ INFO: possible circular locking d

Re: net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Eric Dumazet
On Tue, 2017-03-14 at 14:31 +0100, Dmitry Vyukov wrote: > Hello, > > I've got the following deadlock report while running syzkaller fuzzer > on net-next/92cd12c5ed432c5eebd2462d666772a8d8442c3b: > > > [ INFO: possible circular locking dependency detected ] > 4.10.0+ #29 Not tainted > ---

net: deadlock between ip_expire/sch_direct_xmit

2017-03-14 Thread Dmitry Vyukov
Hello, I've got the following deadlock report while running syzkaller fuzzer on net-next/92cd12c5ed432c5eebd2462d666772a8d8442c3b: [ INFO: possible circular locking dependency detected ] 4.10.0+ #29 Not tainted --- modprobe/12392 is trying to a