======================================================
WARNING: possible circular locking dependency detected
6.2.0-syzkaller-12485-gf3a2439f20d9 #0 Not tainted
------------------------------------------------------
syz-executor.4/9200 is trying to acquire lock:
ffff88802d1d15c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff88802d1d15c8 (&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:
ffff8880716dd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff8880716dd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x2c/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+0x33/0x40 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:355 [inline]
       j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081
       __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1128
       j1939_tp_rxtimer+0x3df/0x4b0 net/can/j1939/transport.c:1253
       __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
       __hrtimer_run_queues+0x690/0x1010 kernel/time/hrtimer.c:1749
       hrtimer_run_softirq+0x17f/0x360 kernel/time/hrtimer.c:1766
       __do_softirq+0x2e3/0xae3 kernel/softirq.c:571
       run_ksoftirqd kernel/softirq.c:934 [inline]
       run_ksoftirqd+0x31/0x60 kernel/softirq.c:926
       smpboot_thread_fn+0x659/0xa20 kernel/smpboot.c:164
       kthread+0x2e8/0x3a0 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

-> #1 (&priv->active_session_list_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x33/0x40 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+0x47/0x4b0 net/can/j1939/transport.c:1557
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x2bf/0x4d0 net/can/j1939/socket.c:208
       j1939_session_deactivate_activate_next net/can/j1939/transport.c:1105 [inline]
       j1939_session_completed+0xb6/0x170 net/can/j1939/transport.c:1218
       j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1388 [inline]
       j1939_xtp_rx_eoma+0x2a1/0x680 net/can/j1939/transport.c:1403
       j1939_tp_cmd_recv net/can/j1939/transport.c:2092 [inline]
       j1939_tp_recv+0x71e/0xf50 net/can/j1939/transport.c:2137
       j1939_can_recv net/can/j1939/main.c:112 [inline]
       j1939_can_recv+0x78e/0xa80 net/can/j1939/main.c:38
       deliver net/can/af_can.c:572 [inline]
       can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606
       can_receive+0x31d/0x5c0 net/can/af_can.c:663
       can_rcv+0x1e1/0x280 net/can/af_can.c:687
       __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5477
       __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5591
       process_backlog+0x279/0x850 net/core/dev.c:5919
       __napi_poll+0xb8/0x870 net/core/dev.c:6480
       napi_poll net/core/dev.c:6547 [inline]
       net_rx_action+0x9fd/0xdc0 net/core/dev.c:6657
       __do_softirq+0x2e3/0xae3 kernel/softirq.c:571
       run_ksoftirqd kernel/softirq.c:934 [inline]
       run_ksoftirqd+0x31/0x60 kernel/softirq.c:926
       smpboot_thread_fn+0x659/0xa20 kernel/smpboot.c:164
       kthread+0x2e8/0x3a0 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

-> #0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain kernel/locking/lockdep.c:3832 [inline]
       __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
       lock_acquire kernel/locking/lockdep.c:5669 [inline]
       lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x33/0x40 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+0x7f/0x160 net/can/j1939/socket.c:1275
       j1939_netdev_notify+0x19d/0x1d0 net/can/j1939/main.c:379
       notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
       call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1937
       call_netdevice_notifiers_extack net/core/dev.c:1975 [inline]
       call_netdevice_notifiers net/core/dev.c:1989 [inline]
       __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8566
       dev_change_flags+0x11b/0x170 net/core/dev.c:8602
       do_setlink+0x9f4/0x3d30 net/core/rtnetlink.c:2833
       __rtnl_newlink+0xd69/0x1840 net/core/rtnetlink.c:3623
       rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3670
       rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6174
       netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
       netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
       netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
       netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1942
       sock_sendmsg_nosec net/socket.c:722 [inline]
       sock_sendmsg+0xde/0x190 net/socket.c:745
       ____sys_sendmsg+0x71c/0x900 net/socket.c:2504
       ___sys_sendmsg+0x110/0x1b0 net/socket.c:2558
       __sys_sendmsg+0xf7/0x1c0 net/socket.c:2587
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 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.4/9200:
 #0: ffffffff8e0faa88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline]
 #0: ffffffff8e0faa88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e8/0xd50 net/core/rtnetlink.c:6171
 #1: ffff8880716dd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
 #1: ffff8880716dd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x2c/0x160 net/can/j1939/socket.c:1269

stack backtrace:
CPU: 1 PID: 9200 Comm: syz-executor.4 Not tainted 6.2.0-syzkaller-12485-gf3a2439f20d9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain kernel/locking/lockdep.c:3832 [inline]
 __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
 lock_acquire kernel/locking/lockdep.c:5669 [inline]
 lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x33/0x40 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+0x7f/0x160 net/can/j1939/socket.c:1275
 j1939_netdev_notify+0x19d/0x1d0 net/can/j1939/main.c:379
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1937
 call_netdevice_notifiers_extack net/core/dev.c:1975 [inline]
 call_netdevice_notifiers net/core/dev.c:1989 [inline]
 __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8566
 dev_change_flags+0x11b/0x170 net/core/dev.c:8602
 do_setlink+0x9f4/0x3d30 net/core/rtnetlink.c:2833
 __rtnl_newlink+0xd69/0x1840 net/core/rtnetlink.c:3623
 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3670
 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6174
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1942
 sock_sendmsg_nosec net/socket.c:722 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:745
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2504
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2558
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2587
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f362e48c0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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:00007f362f169168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f362e5abf80 RCX: 00007f362e48c0f9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000007
RBP: 00007f362e4e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc2aded48f R14: 00007f362f169300 R15: 0000000000022000
 </TASK>