Re: kern/55680: llentry_free panic

[Kimmo Suominen <kim%netbsd.org@localhost>]

The following reply was made to PR kern/55680; it has been noted by GNATS.

From: Kimmo Suominen <kim%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/55680: llentry_free panic
Date: Wed, 23 Sep 2020 07:06:35 +0300

 Hi!
 
 > sysctl net.inet6.ip6.forwarding
 net.inet6.ip6.forwarding = 0
 
 And normally there are two routers learned by the kernel from RAs (not
 running dhcpcd):
 
 > ndp -r
 fe80::822a:a8ff:fe4f:8c3a%vioif0 if=vioif0, flags=, pref=high, expire=21m43s
 fe80::de9f:dbff:fe28:91fa%vioif0 if=vioif0, flags=, pref=medium, expire=28m49s
 
 I've rebooted the same router (pref=high) two more times since without
 a panic, so it would appear to be timing related.
 
 Kind regards,
 + Kimmo
 
 On Wed, 23 Sep 2020 at 05:55, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
 >
 > The following reply was made to PR kern/55680; it has been noted by GNATS.
 >
 > From: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
 > To: Kimmo Suominen <kim%netbsd.org@localhost>
 > Cc: "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%netbsd.org@localhost>, kern-bug-people%netbsd.org@localhost,
 >         gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
 > Subject: Re: kern/55680: llentry_free panic
 > Date: Wed, 23 Sep 2020 11:52:36 +0900
 >
 >  On Wed, Sep 23, 2020 at 12:40 AM Kimmo Suominen <kim%netbsd.org@localhost> wrote:
 >  >
 >  > >Number:         55680
 >  > >Category:       kern
 >  > >Synopsis:       llentry_free panic
 >  > >Confidential:   no
 >  > >Severity:       non-critical
 >  > >Priority:       medium
 >  > >Responsible:    kern-bug-people
 >  > >State:          open
 >  > >Class:          sw-bug
 >  > >Submitter-Id:   net
 >  > >Arrival-Date:   Tue Sep 22 15:40:00 +0000 2020
 >  > >Originator:     Kimmo Suominen
 >  > >Release:        NetBSD 9.0_STABLE (202009201240Z)
 >  > >Organization:
 >  > >Environment:
 >  > System: NetBSD chronologie.gw.fi 9.0_STABLE NetBSD 9.0_STABLE (GENERIC) #0: Sun Sep 20 10:17:44 UTC 2020 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
 >  > Architecture: x86_64
 >  > Machine: amd64
 >  > >Description:
 >  > I rebooted the currently selected default router (high pref) and the system paniced.
 >  >
 >  > panic: pr_item_bitmap_put: [llentrypl] 0xffff88bff9db2330 already freed
 >  > cpu1: Begin traceback...
 >  > vpanic() at netbsd:vpanic+0x160
 >  > snprintf() at netbsd:snprintf
 >  > pool_put() at netbsd:pool_put+0x492
 >  > llentry_free() at netbsd:llentry_free+0xad
 >  > nd6_free() at netbsd:nd6_free+0x161
 >  > nd6_llinfo_timer() at netbsd:nd6_llinfo_timer+0x388
 >  > callout_softclock() at netbsd:callout_softclock+0xc6
 >  > softint_dispatch() at netbsd:softint_dispatch+0xab
 >  > DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xffffcc8031e9b0f0
 >  > Xsoftintr() at netbsd:Xsoftintr+0x4f
 >  > --- interrupt ---
 >  > 0:
 >  > cpu1: End traceback...
 >  > >How-To-Repeat:
 >  > Reboot a router?
 >  > >Fix:
 >  >
 >
 >  One question.  Is net.inet6.ip6.forwarding of your system 1 or 0?
 >
 >  Thanks,
 >    ozaki-r
 >