syzbot

======================================================
WARNING: possible circular locking dependency detected
6.6.0-syzkaller-16176-g1b907d050735 #0 Not tainted
------------------------------------------------------
syz-executor139/5203 is trying to acquire lock:
ffff8880747810d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880747810d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0x96/0x150 net/can/j1939/socket.c:1083

but task is already holding lock:
ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x47/0x480 net/can/j1939/transport.c:2183

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&priv->active_session_list_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
       j1939_session_activate+0x51/0x3e0 net/can/j1939/transport.c:1564
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x26c/0x3f0 net/can/j1939/socket.c:208
       j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline]
       j1939_session_completed net/can/j1939/transport.c:1222 [inline]
       j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1395 [inline]
       j1939_xtp_rx_eoma+0x323/0x530 net/can/j1939/transport.c:1410
       j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline]
       j1939_tp_recv+0x88e/0x1050 net/can/j1939/transport.c:2144
       j1939_can_recv+0x732/0xb20 net/can/j1939/main.c:112
       deliver net/can/af_can.c:572 [inline]
       can_rcv_filter+0x349/0x7c0 net/can/af_can.c:606
       can_receive+0x327/0x480 net/can/af_can.c:663
       can_rcv+0x144/0x260 net/can/af_can.c:687
       __netif_receive_skb_one_core net/core/dev.c:5527 [inline]
       __netif_receive_skb+0x1ca/0x530 net/core/dev.c:5641
       process_backlog+0x385/0x760 net/core/dev.c:5969
       __napi_poll+0xc7/0x470 net/core/dev.c:6531
       napi_poll net/core/dev.c:6600 [inline]
       net_rx_action+0x78b/0x1010 net/core/dev.c:6733
       __do_softirq+0x2bf/0x93a kernel/softirq.c:553
       do_softirq+0x11b/0x1e0 kernel/softirq.c:454
       __local_bh_enable_ip+0x1b5/0x1f0 kernel/softirq.c:381
       spin_unlock_bh include/linux/spinlock.h:396 [inline]
       batadv_nc_purge_paths+0x309/0x3a0 net/batman-adv/network-coding.c:471
       batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
       process_one_work kernel/workqueue.c:2630 [inline]
       process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703
       worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784
       kthread+0x2d3/0x370 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

-> #1 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       j1939_sk_queue_drop_all+0x3a/0x240 net/can/j1939/socket.c:139
       j1939_sk_netdev_event_netdown+0xed/0x160 net/can/j1939/socket.c:1282
       j1939_netdev_notify+0x20d/0x2e0 net/can/j1939/main.c:381
       notifier_call_chain+0x18c/0x3a0 kernel/notifier.c:93
       call_netdevice_notifiers_extack net/core/dev.c:2003 [inline]
       call_netdevice_notifiers net/core/dev.c:2017 [inline]
       dev_close_many+0x336/0x4b0 net/core/dev.c:1558
       unregister_netdevice_many_notify+0x520/0x1710 net/core/dev.c:10956
       rtnl_delete_link net/core/rtnetlink.c:3263 [inline]
       rtnl_dellink+0x523/0x8d0 net/core/rtnetlink.c:3315
       rtnetlink_rcv_msg+0x882/0x1030 net/core/rtnetlink.c:6558
       netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
       netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
       netlink_unicast+0x7e6/0x980 net/netlink/af_netlink.c:1368
       netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg net/socket.c:745 [inline]
       ____sys_sendmsg+0x592/0x890 net/socket.c:2584
       ___sys_sendmsg net/socket.c:2638 [inline]
       __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (&priv->j1939_socks_lock){+.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       j1939_sk_errqueue+0x96/0x150 net/can/j1939/socket.c:1083
       __j1939_session_release net/can/j1939/transport.c:294 [inline]
       kref_put include/linux/kref.h:65 [inline]
       j1939_session_put+0xff/0x460 net/can/j1939/transport.c:299
       j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline]
       j1939_cancel_active_session+0x354/0x480 net/can/j1939/transport.c:2194
       j1939_netdev_notify+0x205/0x2e0 net/can/j1939/main.c:380
       notifier_call_chain+0x18c/0x3a0 kernel/notifier.c:93
       call_netdevice_notifiers_extack net/core/dev.c:2003 [inline]
       call_netdevice_notifiers net/core/dev.c:2017 [inline]
       dev_close_many+0x336/0x4b0 net/core/dev.c:1558
       unregister_netdevice_many_notify+0x520/0x1710 net/core/dev.c:10956
       rtnl_delete_link net/core/rtnetlink.c:3263 [inline]
       rtnl_dellink+0x523/0x8d0 net/core/rtnetlink.c:3315
       rtnetlink_rcv_msg+0x882/0x1030 net/core/rtnetlink.c:6558
       netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
       netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
       netlink_unicast+0x7e6/0x980 net/netlink/af_netlink.c:1368
       netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg net/socket.c:745 [inline]
       ____sys_sendmsg+0x592/0x890 net/socket.c:2584
       ___sys_sendmsg net/socket.c:2638 [inline]
       __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

2 locks held by syz-executor139/5203:
 #0: ffffffff8eb36e88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8eb36e88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1030 net/core/rtnetlink.c:6555
 #1: ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #1: ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
 #1: ffff888074781088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x47/0x480 net/can/j1939/transport.c:2183

stack backtrace:
CPU: 1 PID: 5203 Comm: syz-executor139 Not tainted 6.6.0-syzkaller-16176-g1b907d050735 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3868 [inline]
 __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 j1939_sk_errqueue+0x96/0x150 net/can/j1939/socket.c:1083
 __j1939_session_release net/can/j1939/transport.c:294 [inline]
 kref_put include/linux/kref.h:65 [inline]
 j1939_session_put+0xff/0x460 net/can/j1939/transport.c:299
 j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline]
 j1939_cancel_active_session+0x354/0x480 net/can/j1939/transport.c:2194
 j1939_netdev_notify+0x205/0x2e0 net/can/j1939/main.c:380
 notifier_call_chain+0x18c/0x3a0 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2003 [inline]
 call_netdevice_notifiers net/core/dev.c:2017 [inline]
 dev_close_many+0x336/0x4b0 net/core/dev.c:1558
 unregister_netdevice_many_notify+0x520/0x1710 net/core/dev.c:10956
 rtnl_delete_link net/core/rtnetlink.c:3263 [inline]
 rtnl_dellink+0x523/0x8d0 net/core/rtnetlink.c:3315
 rtnetlink_rcv_msg+0x882/0x1030 net/core/rtnetlink.c:6558
 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x7e6/0x980 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x592/0x890 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f959b6e2329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 1c 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f959b679168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f959b772218 RCX: 00007f959b6e2329
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000008
RBP: 00007f959b772210 R08: 00007f959b6796c0 R09: 00007f959b772218
R10: 00007f959b6796c0 R11: 0000000000000246 R12: 00007f959b77221c
R13: 000000000000006e R14: 00007ffdaabfee70 R15: 00007ffdaabfef58
 </TASK>