Hi all, hi Kurt, i'm aware that J1939 as been redesigned and rewritten, but anyway, may be this can help. We are using old J1939 implementation from Kurt, with iproute2 patched, based on a 3.10 kernel. Making some test we've seen that when adding twice an interface with her name, this leads to a kernel panic. The way to reproduce: ip link set can0 up type can bitrate 250000 ip link set can0 j1939 on ip addr add j1939 name 12345678 dev can0 ip addr add j1939 name 12345678 dev can0 => kernel panic after some debuging, it seems that in bus.c/j1939_ecu_get_register, when it is called the second time, we have a goto duplicate in the duplicate section, we call the macro ecu_alert, which wants to display ecu->parent.ifindex But the ecu->parent is set after the goto, so we have anull pointer i've made this little patch to avoid crashing ------------------------------------------------------------------------------------------ net/can/sj1939/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/can/sj1939/bus.c b/net/can/sj1939/bus.c index dd3a3adfb2a..1625817e7aa 100644 --- a/net/can/sj1939/bus.c +++ b/net/can/sj1939/bus.c @@ -206,6 +206,8 @@ struct j1939_ecu *j1939_ecu_get_register(name_t name, int ifindex, int flags, ecu->sa = J1939_IDLE_ADDR; ecu->name = name; ecu->flags = flags; + /* a ref to parent is held */ + ecu->parent = parent; hrtimer_init(&ecu->ac_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ecu->ac_timer.function = j1939_ecu_timer_handler; @@ -219,8 +221,6 @@ struct j1939_ecu *j1939_ecu_get_register(name_t name, int ifindex, int flags, goto duplicate; } get_j1939_ecu(ecu); - /* a ref to parent is held */ - ecu->parent = parent; list_add_tail(&ecu->list, &parent->ecus); write_unlock_bh(&parent->lock); ecu_dbg(ecu, "register\n"); -- ------------------------------------------------------------------------------------------ I hope it can be usefull to people using this old version. Regards Laurent
