netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'.
======================================================
WARNING: possible circular locking dependency detected
5.17.0-rc1-syzkaller-00339-g169387e2aa29 #0 Not tainted
------------------------------------------------------
syz-executor.5/24247 is trying to acquire lock:
ffff888072b555c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:354 [inline]
ffff888072b555c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_drop_all+0x40/0x2f0 net/can/j1939/socket.c:139

but task is already holding lock:
ffff88801c6190d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:354 [inline]
ffff88801c6190d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 net/can/j1939/socket.c:1266

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:354 [inline]
       j1939_sk_errqueue+0x9f/0x1a0 net/can/j1939/socket.c:1078
       __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1124
       j1939_tp_rxtimer.cold+0x15e/0x1aa net/can/j1939/transport.c:1249
       __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
       __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749
       hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766
       __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
       do_softirq.part.0+0xde/0x130 kernel/softirq.c:459
       do_softirq kernel/softirq.c:451 [inline]
       __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:383
       local_bh_enable include/linux/bottom_half.h:33 [inline]
       rcu_read_unlock_bh include/linux/rcupdate.h:764 [inline]
       ip_finish_output2+0x7d0/0x2170 net/ipv4/ip_output.c:229
       __ip_finish_output net/ipv4/ip_output.c:306 [inline]
       __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288
       ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:316
       NF_HOOK_COND include/linux/netfilter.h:296 [inline]
       ip_output+0x196/0x310 net/ipv4/ip_output.c:430
       dst_output include/net/dst.h:451 [inline]
       ip_local_out net/ipv4/ip_output.c:126 [inline]
       __ip_queue_xmit+0x8fe/0x1bb0 net/ipv4/ip_output.c:532
       __tcp_transmit_skb+0x187d/0x3810 net/ipv4/tcp_output.c:1402
       tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
       tcp_write_xmit+0xd91/0x5f70 net/ipv4/tcp_output.c:2680
       __tcp_push_pending_frames+0xaa/0x390 net/ipv4/tcp_output.c:2864
       tcp_push+0x44d/0x6d0 net/ipv4/tcp.c:725
       tcp_sendmsg_locked+0x264c/0x3050 net/ipv4/tcp.c:1413
       tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1441
       inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
       sock_sendmsg_nosec net/socket.c:705 [inline]
       sock_sendmsg+0xcf/0x120 net/socket.c:725
       sock_write_iter+0x289/0x3c0 net/socket.c:1061
       call_write_iter include/linux/fs.h:2074 [inline]
       new_sync_write+0x431/0x660 fs/read_write.c:503
       vfs_write+0x7cd/0xae0 fs/read_write.c:590
       ksys_write+0x1ee/0x250 fs/read_write.c:643
       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+0x44/0xae

-> #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:354 [inline]
       j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
       j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1553
       j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline]
       j1939_sk_queue_activate_next+0x29b/0x460 net/can/j1939/socket.c:205
       j1939_session_deactivate_activate_next net/can/j1939/transport.c:1101 [inline]
       j1939_session_completed+0x80/0x120 net/can/j1939/transport.c:1214
       j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1384 [inline]
       j1939_xtp_rx_eoma+0x2a6/0x5f0 net/can/j1939/transport.c:1399
       j1939_tp_cmd_recv net/can/j1939/transport.c:2088 [inline]
       j1939_tp_recv+0x930/0xcb0 net/can/j1939/transport.c:2133
       j1939_can_recv+0x6ff/0x9a0 net/can/j1939/main.c:108
       deliver net/can/af_can.c:574 [inline]
       can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:608
       can_receive+0x31d/0x580 net/can/af_can.c:665
       can_rcv+0x120/0x1c0 net/can/af_can.c:696
       __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5351
       __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5465
       process_backlog+0x2a5/0x6c0 net/core/dev.c:5797
       __napi_poll+0xaf/0x440 net/core/dev.c:6365
       napi_poll net/core/dev.c:6432 [inline]
       net_rx_action+0x801/0xb40 net/core/dev.c:6519
       __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
       run_ksoftirqd kernel/softirq.c:921 [inline]
       run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913
       smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
       kthread+0x2e9/0x3a0 kernel/kthread.c:377
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3063 [inline]
       check_prevs_add kernel/locking/lockdep.c:3186 [inline]
       validate_chain kernel/locking/lockdep.c:3801 [inline]
       __lock_acquire+0x2a2c/0x5470 kernel/locking/lockdep.c:5027
       lock_acquire kernel/locking/lockdep.c:5639 [inline]
       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
       __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:354 [inline]
       j1939_sk_queue_drop_all+0x40/0x2f0 net/can/j1939/socket.c:139
       j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1272
       j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:372
       notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
       call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919
       call_netdevice_notifiers_extack net/core/dev.c:1931 [inline]
       call_netdevice_notifiers net/core/dev.c:1945 [inline]
       __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8179
       dev_change_flags+0x112/0x170 net/core/dev.c:8215
       do_setlink+0x96d/0x3a10 net/core/rtnetlink.c:2729
       __rtnl_newlink+0xde7/0x1750 net/core/rtnetlink.c:3412
       rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3527
       rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5592
       netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
       netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
       netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343
       netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919
       sock_sendmsg_nosec net/socket.c:705 [inline]
       sock_sendmsg+0xcf/0x120 net/socket.c:725
       ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413
       ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
       __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
       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+0x44/0xae

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.5/24247:
 #0: ffffffff8d33c8e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d33c8e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5589
 #1: ffff88801c6190d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:354 [inline]
 #1: ffff88801c6190d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 net/can/j1939/socket.c:1266

stack backtrace:
CPU: 1 PID: 24247 Comm: syz-executor.5 Not tainted 5.17.0-rc1-syzkaller-00339-g169387e2aa29 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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:2143
 check_prev_add kernel/locking/lockdep.c:3063 [inline]
 check_prevs_add kernel/locking/lockdep.c:3186 [inline]
 validate_chain kernel/locking/lockdep.c:3801 [inline]
 __lock_acquire+0x2a2c/0x5470 kernel/locking/lockdep.c:5027
 lock_acquire kernel/locking/lockdep.c:5639 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
 __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:354 [inline]
 j1939_sk_queue_drop_all+0x40/0x2f0 net/can/j1939/socket.c:139
 j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1272
 j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:372
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919
 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline]
 call_netdevice_notifiers net/core/dev.c:1945 [inline]
 __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8179
 dev_change_flags+0x112/0x170 net/core/dev.c:8215
 do_setlink+0x96d/0x3a10 net/core/rtnetlink.c:2729
 __rtnl_newlink+0xde7/0x1750 net/core/rtnetlink.c:3412
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3527
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5592
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 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+0x44/0xae
RIP: 0033:0x7fcedf1a9059
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:00007fceddafd168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcedf2bc030 RCX: 00007fcedf1a9059
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007fcedf20308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcedf7efb1f R14: 00007fceddafd300 R15: 0000000000022000
 </TASK>
netlink: 16 bytes leftover after parsing attributes in process `syz-executor.5'.