IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc3-syzkaller-00299-g2f5065a0bc9d #0 Not tainted
------------------------------------------------------
syz-executor.2/26798 is trying to acquire lock:
ffff8880260635c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff8880260635c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139

but task is already holding lock:
ffff8880810890d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff8880810890d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 net/can/j1939/socket.c:1269

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&priv->j1939_socks_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:355 [inline]
       j1939_sk_errqueue+0x9f/0x1a0 net/can/j1939/socket.c:1081
       __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1132
       j1939_tp_rxtimer.cold+0x1f6/0x24f net/can/j1939/transport.c:1257
       __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
       __hrtimer_run_queues+0x690/0xfb0 kernel/time/hrtimer.c:1749
       hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766
       __do_softirq+0x1f7/0xad8 kernel/softirq.c:571
       invoke_softirq kernel/softirq.c:445 [inline]
       __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
       sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1107
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
       lock_acquire+0x223/0x630 kernel/locking/lockdep.c:5636
       rcu_lock_acquire include/linux/rcupdate.h:304 [inline]
       rcu_read_lock include/linux/rcupdate.h:738 [inline]
       inet_twsk_purge+0x12e/0x8a0 net/ipv4/inet_timewait_sock.c:268
       ops_exit_list+0x125/0x170 net/core/net_namespace.c:174
       cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:601
       process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
       worker_thread+0x665/0x1080 kernel/workqueue.c:2436
       kthread+0x2e4/0x3a0 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #1 (&priv->active_session_list_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:355 [inline]
       j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
       j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1561
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x1b2/0x450 net/can/j1939/socket.c:208
       j1939_session_deactivate_activate_next net/can/j1939/transport.c:1109 [inline]
       j1939_session_completed+0x19a/0x1f0 net/can/j1939/transport.c:1222
       j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1392 [inline]
       j1939_xtp_rx_eoma+0x2a1/0x5e0 net/can/j1939/transport.c:1407
       j1939_tp_cmd_recv net/can/j1939/transport.c:2096 [inline]
       j1939_tp_recv+0x930/0xcb0 net/can/j1939/transport.c:2141
       j1939_can_recv net/can/j1939/main.c:112 [inline]
       j1939_can_recv+0x78a/0xa30 net/can/j1939/main.c:38
       deliver net/can/af_can.c:573 [inline]
       can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:607
       can_receive+0x31d/0x580 net/can/af_can.c:664
       can_rcv+0x162/0x1a0 net/can/af_can.c:688
       __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5489
       __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5603
       process_backlog+0x3e0/0x810 net/core/dev.c:5931
       __napi_poll+0xb8/0x770 net/core/dev.c:6498
       napi_poll net/core/dev.c:6565 [inline]
       net_rx_action+0x9fc/0xde0 net/core/dev.c:6676
       __do_softirq+0x1f7/0xad8 kernel/softirq.c:571
       run_ksoftirqd kernel/softirq.c:934 [inline]
       run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926
       smpboot_thread_fn+0x645/0xa00 kernel/smpboot.c:164
       kthread+0x2e4/0x3a0 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

-> #0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain kernel/locking/lockdep.c:3831 [inline]
       __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
       lock_acquire kernel/locking/lockdep.c:5668 [inline]
       lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:355 [inline]
       j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139
       j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1275
       j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:376
       notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
       call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945
       call_netdevice_notifiers_extack net/core/dev.c:1983 [inline]
       call_netdevice_notifiers net/core/dev.c:1997 [inline]
       __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8583
       dev_change_flags+0x112/0x170 net/core/dev.c:8619
       do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2788
       __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3547
       rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3594
       rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6091
       netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
       sock_sendmsg_nosec net/socket.c:714 [inline]
       sock_sendmsg+0xcf/0x120 net/socket.c:734
       ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482
       ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
       __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &jsk->sk_session_queue_lock --> &priv->active_session_list_lock --> &priv->j1939_socks_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&priv->j1939_socks_lock);
                               lock(&priv->active_session_list_lock);
                               lock(&priv->j1939_socks_lock);
  lock(&jsk->sk_session_queue_lock);

 *** DEADLOCK ***

2 locks held by syz-executor.2/26798:
 #0: ffffffff8d7b7de8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8d7b7de8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e5/0xca0 net/core/rtnetlink.c:6088
 #1: ffff8880810890d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
 #1: ffff8880810890d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 net/can/j1939/socket.c:1269

stack backtrace:
CPU: 1 PID: 26798 Comm: syz-executor.2 Not tainted 6.1.0-rc3-syzkaller-00299-g2f5065a0bc9d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain kernel/locking/lockdep.c:3831 [inline]
 __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:355 [inline]
 j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139
 j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1275
 j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:376
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945
 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline]
 call_netdevice_notifiers net/core/dev.c:1997 [inline]
 __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8583
 dev_change_flags+0x112/0x170 net/core/dev.c:8619
 do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2788
 __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3547
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3594
 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6091
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f3e0fa8b5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3e10755168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3e0fbabf80 RCX: 00007f3e0fa8b5a9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000007
RBP: 00007f3e0fae67b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff7195f36f R14: 00007f3e10755300 R15: 0000000000022000
 </TASK>