IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
======================================================
WARNING: possible circular locking dependency detected
6.2.0-rc2-syzkaller-00010-g69b41ac87e4a #0 Not tainted
------------------------------------------------------
syz-executor.3/20675 is trying to acquire lock:
ffff88803f1c15c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff88803f1c15c8 (&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:
ffff8880755390d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff8880755390d0 (&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: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+0x17f/0x360 kernel/time/hrtimer.c:1766
       __do_softirq+0x1fb/0xadc kernel/softirq.c:571
       invoke_softirq kernel/softirq.c:445 [inline]
       __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
       irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
       sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
       orc_ip arch/x86/kernel/unwind_orc.c:30 [inline]
       __orc_find+0x6f/0xf0 arch/x86/kernel/unwind_orc.c:52
       orc_find arch/x86/kernel/unwind_orc.c:193 [inline]
       unwind_next_frame+0x2a7/0x1d00 arch/x86/kernel/unwind_orc.c:467
       arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25
       stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122
       kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
       kasan_set_track+0x25/0x30 mm/kasan/common.c:52
       kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
       ____kasan_slab_free mm/kasan/common.c:236 [inline]
       ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
       kasan_slab_free include/linux/kasan.h:177 [inline]
       slab_free_hook mm/slub.c:1781 [inline]
       slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
       slab_free mm/slub.c:3787 [inline]
       __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800
       iter_file_splice_write+0x244/0xc90 fs/splice.c:714
       do_splice_from fs/splice.c:764 [inline]
       direct_splice_actor+0x114/0x180 fs/splice.c:931
       splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886
       do_splice_direct+0x1ab/0x280 fs/splice.c:974
       do_sendfile+0xb19/0x1270 fs/read_write.c:1255
       __do_sys_sendfile64 fs/read_write.c:1317 [inline]
       __se_sys_sendfile64 fs/read_write.c:1309 [inline]
       __x64_sys_sendfile64+0x14d/0x210 fs/read_write.c:1309
       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

-> #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:1561
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x1b6/0x450 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+0x71c/0xcd0 net/can/j1939/transport.c:2141
       j1939_can_recv net/can/j1939/main.c:112 [inline]
       j1939_can_recv+0x78e/0xa30 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/0x580 net/can/af_can.c:663
       can_rcv+0x1e1/0x230 net/can/af_can.c:687
       __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5482
       __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5596
       process_backlog+0x3e4/0x810 net/core/dev.c:5924
       __napi_poll+0xb8/0x770 net/core/dev.c:6485
       napi_poll net/core/dev.c:6552 [inline]
       net_rx_action+0xa00/0xde0 net/core/dev.c:6663
       __do_softirq+0x1fb/0xadc kernel/softirq.c:571
       do_softirq.part.0+0xde/0x130 kernel/softirq.c:472
       do_softirq kernel/softirq.c:464 [inline]
       __local_bh_enable_ip+0x106/0x130 kernel/softirq.c:396
       spin_unlock_bh include/linux/spinlock.h:395 [inline]
       batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:471
       batadv_nc_worker+0x934/0xfa0 net/batman-adv/network-coding.c:722
       process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
       worker_thread+0x669/0x1090 kernel/workqueue.c:2436
       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: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+0x1e3/0x630 kernel/locking/lockdep.c:5633
       __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:1944
       call_netdevice_notifiers_extack net/core/dev.c:1982 [inline]
       call_netdevice_notifiers net/core/dev.c:1996 [inline]
       __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571
       dev_change_flags+0x11b/0x170 net/core/dev.c:8607
       do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2827
       __rtnl_newlink+0xd69/0x1840 net/core/rtnetlink.c:3590
       rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637
       rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141
       netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564
       netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
       netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356
       netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932
       sock_sendmsg_nosec net/socket.c:714 [inline]
       sock_sendmsg+0xd3/0x120 net/socket.c:734
       ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476
       ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
       __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559
       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.3/20675:
 #0: ffffffff8e0bdea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline]
 #0: ffffffff8e0bdea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e9/0xca0 net/core/rtnetlink.c:6138
 #1: ffff8880755390d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
 #1: ffff8880755390d0 (&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: 20675 Comm: syz-executor.3 Not tainted 6.2.0-rc2-syzkaller-00010-g69b41ac87e4a #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+0xd1/0x138 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+0x1e3/0x630 kernel/locking/lockdep.c:5633
 __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:1944
 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline]
 call_netdevice_notifiers net/core/dev.c:1996 [inline]
 __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571
 dev_change_flags+0x11b/0x170 net/core/dev.c:8607
 do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2827
 __rtnl_newlink+0xd69/0x1840 net/core/rtnetlink.c:3590
 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637
 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564
 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356
 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xd3/0x120 net/socket.c:734
 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559
 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: 0033:0x7fc47e28c0a9
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:00007fc47f06b168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc47e3abf80 RCX: 00007fc47e28c0a9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000007
RBP: 00007fc47e2e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc9e1bcbaf R14: 00007fc47f06b300 R15: 0000000000022000
 </TASK>