On Thu, Nov 13, 2025 at 11:07:28PM +0300, Vitaliy Makkoveev wrote:
> On Thu, Nov 13, 2025 at 11:05:46AM -0800, Mark McBride wrote:
> > I can trigger a kernel panic if I start the syncthing service.
> >
> > rcctl start syncthing_markmcb
> >
> > ... wait 5-10 seconds ...
> >
> > panic: netlock rwlock 0xffffff80012492d0: exit write when lock not held
> > (owner 0
> > x10, self 0xffffff809ee7ad24)
> > Stopped at db_enter+0x18: brk #0xf000
> > TID PID UID PRFLAGS PFLAGS CPU COMMAND
> > 87509 73883 1000 0x3 0 2 syncthing
> > 468519 73883 1000 0x3 0x4000000 3 syncthing
> > * 29160 73883 1000 0x3 0x4000000 1 syncthing
> > 3 22537 73883 1000 0x3 0x4000000 0 syncthing
> > db_enter() at panic+0x138
> > panic() at rw_exit_write+0xd0
> > _rw_init_flags() at cad_ioctl+0x80
> > cad_ioctl() at in_delmulti+0xbc
> > in_delmulti() at ip_freemoptions+0x3c
> > ip_freemoptions() at in_pcbdetach+0x5c
> > in_pcbdetach() at udp_detach+0x2c
> >
>
> We don't hold netlock wile performing SIOC{G,S}IFMEDIA ifioctl()
> commands, so add them to exception list too.
>
Ops, they already are. Please drop this diff.
> I can't test this diff.
>
> Index: sys/dev/fdt/if_cad.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/fdt/if_cad.c,v
> retrieving revision 1.16
> diff -u -p -r1.16 if_cad.c
> --- sys/dev/fdt/if_cad.c 17 Sep 2025 09:17:12 -0000 1.16
> +++ sys/dev/fdt/if_cad.c 13 Nov 2025 20:05:02 -0000
> @@ -596,6 +596,8 @@ cad_ioctl(struct ifnet *ifp, u_long cmd,
> case SIOCGIFMEDIA:
> case SIOCSIFMEDIA:
> case SIOCGIFSFFPAGE:
> + case SIOCGIFMEDIA:
> + case SIOCSIFMEDIA:
> netlock_held = 0;
> break;
> }
