syzbot

======================================================
WARNING: possible circular locking dependency detected
6.6.0-rc6-syzkaller-00043-gdd72f9c7e512 #0 Not tainted
------------------------------------------------------
syz-executor744/5106 is trying to acquire lock:
ffff888028eab5c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888028eab5c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_drop_all+0x3a/0x240 net/can/j1939/socket.c:139

but task is already holding lock:
ffff888079f690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888079f690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x31/0x160 net/can/j1939/socket.c:1276

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+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
       __dev_notify_flags+0x359/0x650
       dev_change_flags+0xf0/0x1a0 net/core/dev.c:8678
       do_setlink+0xfb2/0x4340 net/core/rtnetlink.c:2880
       __rtnl_newlink net/core/rtnetlink.c:3671 [inline]
       rtnl_newlink+0x17f6/0x2070 net/core/rtnetlink.c:3718
       rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444
       netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
       netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
       netlink_unicast+0x7dc/0x970 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:2558
       ___sys_sendmsg net/socket.c:2612 [inline]
       __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 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+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+0x319/0x470 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:6598 [inline]
       net_rx_action+0x78b/0x1010 net/core/dev.c:6731
       __do_softirq+0x2ab/0x908 kernel/softirq.c:553
       invoke_softirq kernel/softirq.c:427 [inline]
       __irq_exit_rcu+0xf1/0x1b0 kernel/softirq.c:632
       irq_exit_rcu+0x9/0x20 kernel/softirq.c:644
       sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1074
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
       __debug_check_no_obj_freed lib/debugobjects.c:1042 [inline]
       debug_check_no_obj_freed+0x39e/0x420 lib/debugobjects.c:1063
       free_pages_prepare mm/page_alloc.c:1142 [inline]
       free_unref_page_prepare+0x241/0x9f0 mm/page_alloc.c:2312
       free_unref_page+0x37/0x3f0 mm/page_alloc.c:2405
       __slab_free+0x2f6/0x390 mm/slub.c:3715
       qlink_free mm/kasan/quarantine.c:166 [inline]
       qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
       kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292
       ____kasan_kmalloc mm/kasan/common.c:340 [inline]
       __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:383
       kmalloc include/linux/slab.h:599 [inline]
       syslog_print+0x121/0x9b0 kernel/printk/printk.c:1553
       do_syslog+0x505/0x890 kernel/printk/printk.c:1732
       __do_sys_syslog kernel/printk/printk.c:1824 [inline]
       __se_sys_syslog kernel/printk/printk.c:1822 [inline]
       __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1822
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&jsk->sk_session_queue_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_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
       __dev_notify_flags+0x359/0x650
       dev_change_flags+0xf0/0x1a0 net/core/dev.c:8678
       do_setlink+0xfb2/0x4340 net/core/rtnetlink.c:2880
       __rtnl_newlink net/core/rtnetlink.c:3671 [inline]
       rtnl_newlink+0x17f6/0x2070 net/core/rtnetlink.c:3718
       rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444
       netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
       netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
       netlink_unicast+0x7dc/0x970 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:2558
       ___sys_sendmsg net/socket.c:2612 [inline]
       __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x41/0xc0 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-executor744/5106:
 #0: ffffffff8e4d2948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e4d2948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x828/0x1030 net/core/rtnetlink.c:6441
 #1: ffff888079f690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #1: ffff888079f690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x31/0x160 net/can/j1939/socket.c:1276

stack backtrace:
CPU: 1 PID: 5106 Comm: syz-executor744 Not tainted 6.6.0-rc6-syzkaller-00043-gdd72f9c7e512 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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_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
 __dev_notify_flags+0x359/0x650
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8678
 do_setlink+0xfb2/0x4340 net/core/rtnetlink.c:2880
 __rtnl_newlink net/core/rtnetlink.c:3671 [inline]
 rtnl_newlink+0x17f6/0x2070 net/core/rtnetlink.c:3718
 rtnetlink_rcv_msg+0x87e/0x1030 net/core/rtnetlink.c:6444
 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x7dc/0x970 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:2558
 ___sys_sendmsg net/socket.c:2612 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2641
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc42a6e92b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 1a 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:00007fc42a683218 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc42a7791f8 RCX: 00007fc42a6e92b9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007fc42a7791f0 R08: 00007fc42a682fa4 R09: 0000000000000000
R10: 0000000000000014 R11: 0000000000000246 R12: 00007fc42a7791fc
R13: 00007fc42a73f5dc R14: 6c756e2f7665642f R15: 00007fc42a73f01d
 </TASK>