syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.142-syzkaller #0 Not tainted
------------------------------------------------------
ksoftirqd/1/20 is trying to acquire lock:
ffff0000ca30d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000ca30d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
ffff0000ca30d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_activate+0x60/0x388 net/can/j1939/transport.c:1564

but task is already holding lock:
ffff0000caa825d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000caa825d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x60/0x3b4 net/can/j1939/socket.c:207

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:368 [inline]
       j1939_sk_queue_drop_all+0x4c/0x200 net/can/j1939/socket.c:139
       j1939_sk_netdev_event_netdown+0xe0/0x144 net/can/j1939/socket.c:1280
       j1939_netdev_notify+0xf0/0x144 net/can/j1939/main.c:377
       notifier_call_chain kernel/notifier.c:83 [inline]
       raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
       __dev_notify_flags+0x2ac/0x534
       dev_change_flags+0xc8/0x154 net/core/dev.c:8883
       do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2741
       __rtnl_newlink net/core/rtnetlink.c:3429 [inline]
       rtnl_newlink+0x12fc/0x1af4 net/core/rtnetlink.c:3549
       rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5630
       netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
       rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5648
       netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
       netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
       netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
       sock_sendmsg_nosec net/socket.c:704 [inline]
       __sock_sendmsg net/socket.c:716 [inline]
       ____sys_sendmsg+0x584/0x870 net/socket.c:2429
       ___sys_sendmsg+0x214/0x294 net/socket.c:2483
       __sys_sendmsg net/socket.c:2512 [inline]
       __do_sys_sendmsg net/socket.c:2521 [inline]
       __se_sys_sendmsg net/socket.c:2519 [inline]
       __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2519
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #1 (&priv->j1939_socks_lock){+.-.}-{2:2}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:368 [inline]
       j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081
       __j1939_session_release net/can/j1939/transport.c:294 [inline]
       kref_put include/linux/kref.h:65 [inline]
       j1939_session_put+0xf8/0x4f0 net/can/j1939/transport.c:299
       j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline]
       j1939_cancel_active_session+0x2ec/0x414 net/can/j1939/transport.c:2194
       j1939_netdev_notify+0xe8/0x144 net/can/j1939/main.c:376
       notifier_call_chain kernel/notifier.c:83 [inline]
       raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
       __dev_notify_flags+0x2ac/0x534
       dev_change_flags+0xc8/0x154 net/core/dev.c:8883
       do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2741
       __rtnl_newlink net/core/rtnetlink.c:3429 [inline]
       rtnl_newlink+0x12fc/0x1af4 net/core/rtnetlink.c:3549
       rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5630
       netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
       rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5648
       netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
       netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
       netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
       sock_sendmsg_nosec net/socket.c:704 [inline]
       __sock_sendmsg net/socket.c:716 [inline]
       ____sys_sendmsg+0x584/0x870 net/socket.c:2429
       ___sys_sendmsg+0x214/0x294 net/socket.c:2483
       __sys_sendmsg net/socket.c:2512 [inline]
       __do_sys_sendmsg net/socket.c:2521 [inline]
       __se_sys_sendmsg net/socket.c:2519 [inline]
       __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2519
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
       el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
       el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
       el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&priv->active_session_list_lock){+.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
       lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:368 [inline]
       j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
       j1939_session_activate+0x60/0x388 net/can/j1939/transport.c:1564
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x230/0x3b4 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+0x2c0/0x4c0 net/can/j1939/transport.c:1410
       j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline]
       j1939_tp_recv+0x714/0xe14 net/can/j1939/transport.c:2144
       j1939_can_recv+0x568/0x8b4 net/can/j1939/main.c:108
       deliver net/can/af_can.c:574 [inline]
       can_rcv_filter+0x308/0x714 net/can/af_can.c:608
       can_receive+0x344/0x4a0 net/can/af_can.c:665
       can_rcv+0x118/0x274 net/can/af_can.c:696
       __netif_receive_skb_one_core net/core/dev.c:5482 [inline]
       __netif_receive_skb+0x18c/0x400 net/core/dev.c:5596
       process_backlog+0x3ec/0x7e0 net/core/dev.c:6473
       __napi_poll+0xb4/0x624 net/core/dev.c:7032
       napi_poll net/core/dev.c:7099 [inline]
       net_rx_action+0x500/0xc10 net/core/dev.c:7186
       __do_softirq+0x344/0xdb0 kernel/softirq.c:558
       run_ksoftirqd+0x68/0x258 kernel/softirq.c:921
       smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
       kthread+0x37c/0x45c kernel/kthread.c:319
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by ksoftirqd/1/20:
 #0: ffff800014af1560 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:268
 #1: ffff800014af1560 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:268
 #2: ffff0000caa825d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
 #2: ffff0000caa825d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x60/0x3b4 net/can/j1939/socket.c:207

stack backtrace:
CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted 5.15.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:368 [inline]
 j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
 j1939_session_activate+0x60/0x388 net/can/j1939/transport.c:1564
 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
 j1939_sk_queue_activate_next+0x230/0x3b4 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+0x2c0/0x4c0 net/can/j1939/transport.c:1410
 j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline]
 j1939_tp_recv+0x714/0xe14 net/can/j1939/transport.c:2144
 j1939_can_recv+0x568/0x8b4 net/can/j1939/main.c:108
 deliver net/can/af_can.c:574 [inline]
 can_rcv_filter+0x308/0x714 net/can/af_can.c:608
 can_receive+0x344/0x4a0 net/can/af_can.c:665
 can_rcv+0x118/0x274 net/can/af_can.c:696
 __netif_receive_skb_one_core net/core/dev.c:5482 [inline]
 __netif_receive_skb+0x18c/0x400 net/core/dev.c:5596
 process_backlog+0x3ec/0x7e0 net/core/dev.c:6473
 __napi_poll+0xb4/0x624 net/core/dev.c:7032
 napi_poll net/core/dev.c:7099 [inline]
 net_rx_action+0x500/0xc10 net/core/dev.c:7186
 __do_softirq+0x344/0xdb0 kernel/softirq.c:558
 run_ksoftirqd+0x68/0x258 kernel/softirq.c:921
 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870