Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 4/17/18 5:29 PM, Ben Greear wrote: > > FYI, problem still happens in 4.16.  I'm going to re-enable my hack below > for this kernel as well...I had hopes it might be fixed... Interesting. I was hoping the same. > > BUG: unable to handle kernel NULL pointer dereference at 8 > IP:

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 01/24/2018 03:59 PM, Ben Greear wrote: On 06/20/2017 08:03 PM, David Ahern wrote: On 6/20/17 5:41 PM, Ben Greear wrote: On 06/20/2017 11:05 AM, Michal Kubecek wrote: On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: On 06/14/2017 03:25 PM, David Ahern wrote: On 6/14/17 4:23 PM,

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/20/2017 08:03 PM, David Ahern wrote: On 6/20/17 5:41 PM, Ben Greear wrote: On 06/20/2017 11:05 AM, Michal Kubecek wrote: On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: On 06/14/2017 03:25 PM, David Ahern wrote: On 6/14/17 4:23 PM, Ben Greear wrote: On 06/13/2017 07:27 PM,

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/20/17 9:03 PM, David Ahern wrote: > On 6/20/17 5:41 PM, Ben Greear wrote: >> On 06/20/2017 11:05 AM, Michal Kubecek wrote: >>> On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: On 06/14/2017 03:25 PM, David Ahern wrote: > On 6/14/17 4:23 PM, Ben Greear wrote: >> On

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/20/17 5:41 PM, Ben Greear wrote: > On 06/20/2017 11:05 AM, Michal Kubecek wrote: >> On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: >>> On 06/14/2017 03:25 PM, David Ahern wrote: On 6/14/17 4:23 PM, Ben Greear wrote: > On 06/13/2017 07:27 PM, David Ahern wrote: >

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/20/2017 11:05 AM, Michal Kubecek wrote: On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: On 06/14/2017 03:25 PM, David Ahern wrote: On 6/14/17 4:23 PM, Ben Greear wrote: On 06/13/2017 07:27 PM, David Ahern wrote: Let's try a targeted debug patch. See attached I had to

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Tue, Jun 20, 2017 at 07:12:27AM -0700, Ben Greear wrote: > On 06/14/2017 03:25 PM, David Ahern wrote: > >On 6/14/17 4:23 PM, Ben Greear wrote: > >>On 06/13/2017 07:27 PM, David Ahern wrote: > >> > >>>Let's try a targeted debug patch. See attached > >> > >>I had to change it to pr_err so it

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/14/2017 03:25 PM, David Ahern wrote: On 6/14/17 4:23 PM, Ben Greear wrote: On 06/13/2017 07:27 PM, David Ahern wrote: Let's try a targeted debug patch. See attached I had to change it to pr_err so it would go to our serial console since the system locked hard on crash, and that

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/14/17 4:23 PM, Ben Greear wrote: > On 06/13/2017 07:27 PM, David Ahern wrote: > >> Let's try a targeted debug patch. See attached > > I had to change it to pr_err so it would go to our serial console > since the system locked hard on crash, > and that appears to be enough to change the

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/13/2017 07:27 PM, David Ahern wrote: Let's try a targeted debug patch. See attached I had to change it to pr_err so it would go to our serial console since the system locked hard on crash, and that appears to be enough to change the timing where we can no longer reproduce the problem.

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/13/17 3:42 PM, Cong Wang wrote: > On Tue, Jun 13, 2017 at 1:16 PM, Ben Greear wrote: >> On 06/09/2017 02:25 PM, Eric Dumazet wrote: >>> >>> On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: On 6/8/17 11:55 PM, Cong Wang wrote: > Apparently

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Tue, Jun 13, 2017 at 1:16 PM, Ben Greear wrote: > On 06/09/2017 02:25 PM, Eric Dumazet wrote: >> >> On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: >>> >>> On 6/8/17 11:55 PM, Cong Wang wrote: Apparently fn->parent is NULL here for some reason, but I

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/13/2017 01:28 PM, David Ahern wrote: On 6/13/17 2:16 PM, Ben Greear wrote: On 06/09/2017 02:25 PM, Eric Dumazet wrote: On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: On 6/8/17 11:55 PM, Cong Wang wrote: On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote:

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/13/17 2:16 PM, Ben Greear wrote: > On 06/09/2017 02:25 PM, Eric Dumazet wrote: >> On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: >>> On 6/8/17 11:55 PM, Cong Wang wrote: On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote: > > As far as I can

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/09/2017 02:25 PM, Eric Dumazet wrote: On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: On 6/8/17 11:55 PM, Cong Wang wrote: On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote: As far as I can tell, the patch did not help, or at least we still reproduce the

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Fri, 2017-06-09 at 07:27 -0600, David Ahern wrote: > On 6/8/17 11:55 PM, Cong Wang wrote: > > On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote: > >> > >> As far as I can tell, the patch did not help, or at least we still > >> reproduce > >> the > >> crash easily. > >

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/8/17 11:55 PM, Cong Wang wrote: > On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote: >> >> As far as I can tell, the patch did not help, or at least we still reproduce >> the >> crash easily. > > netlink dump is serialized by nlk->cb_mutex so I don't think that >

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Thu, Jun 8, 2017 at 2:27 PM, Ben Greear wrote: > > As far as I can tell, the patch did not help, or at least we still reproduce > the > crash easily. netlink dump is serialized by nlk->cb_mutex so I don't think that patch makes any sense w.r.t race condition. >

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/06/2017 09:19 PM, Eric Dumazet wrote: On Tue, 2017-06-06 at 18:34 -0600, David Ahern wrote: On 6/6/17 6:27 PM, Eric Dumazet wrote: Good catch, but it looks like similar fix is needed a few lines before. diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Tue, 2017-06-06 at 18:34 -0600, David Ahern wrote: > On 6/6/17 6:27 PM, Eric Dumazet wrote: > > Good catch, but it looks like similar fix is needed a few lines before. > > > > diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c > > index > >

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 06/06/2017 05:27 PM, Eric Dumazet wrote: On Tue, 2017-06-06 at 18:00 -0600, David Ahern wrote: On 6/6/17 3:06 PM, Ben Greear wrote: This bug has been around forever, and we recently got an intern and stuck him with trying to reproduce it on the latest kernel. It is still here. I'm not

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/6/17 6:27 PM, Eric Dumazet wrote: > Good catch, but it looks like similar fix is needed a few lines before. > > diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c > index > deea901746c8570c5e801e40592c91e3b62812e0..b214443dc8346cef3690df7f27cc48a864028865 > 100644 > ---

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On Tue, 2017-06-06 at 18:00 -0600, David Ahern wrote: > On 6/6/17 3:06 PM, Ben Greear wrote: > > This bug has been around forever, and we recently got an intern and > > stuck him with > > trying to reproduce it on the latest kernel. It is still here. I'm not > > super excited > > about trying to

Re: Repeatable inet6_dump_fib crash in stock 4.12.0-rc4+

On 6/6/17 3:06 PM, Ben Greear wrote: > This bug has been around forever, and we recently got an intern and > stuck him with > trying to reproduce it on the latest kernel. It is still here. I'm not > super excited > about trying to fix this, but we can easily test patches if someone has a > patch