====================================================== WARNING: possible circular locking dependency detected 6.4.0-syzkaller-12415-g8fc3b8f082cc #0 Not tainted ------------------------------------------------------ ksoftirqd/0/16 is trying to acquire lock: ffff88802c7cd088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802c7cd088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff88802c7cd088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1564 but task is already holding lock: ffff8880238935c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880238935c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x5f/0x4d0 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:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [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:1280 j1939_netdev_notify+0x19f/0x1d0 net/can/j1939/main.c:381 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline] call_netdevice_notifiers net/core/dev.c:2014 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867 __rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0xde/0x190 net/socket.c:748 ____sys_sendmsg+0x739/0x920 net/socket.c:2494 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2548 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2577 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->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:356 [inline] j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081 j1939_session_destroy+0x26c/0x4e0 net/can/j1939/transport.c:271 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put net/can/j1939/transport.c:299 [inline] j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline] j1939_session_deactivate_locked+0x293/0x340 net/can/j1939/transport.c:1074 j1939_cancel_active_session+0x183/0x360 net/can/j1939/transport.c:2194 j1939_netdev_notify+0x197/0x1d0 net/can/j1939/main.c:380 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline] call_netdevice_notifiers net/core/dev.c:2014 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867 __rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0xde/0x190 net/socket.c:748 ____sys_sendmsg+0x739/0x920 net/socket.c:2494 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2548 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2577 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 -> #0 (&priv->active_session_list_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726 __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:356 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1564 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x2bf/0x4d0 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline] j1939_session_completed+0xb6/0x170 net/can/j1939/transport.c:1222 j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1395 [inline] j1939_xtp_rx_eoma+0x2a1/0x680 net/can/j1939/transport.c:1410 j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline] j1939_tp_recv+0x71e/0xf50 net/can/j1939/transport.c:2144 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa80 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/0x5c0 net/can/af_can.c:663 can_rcv+0x1e1/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5452 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5566 process_backlog+0x101/0x670 net/core/dev.c:5894 __napi_poll+0xb7/0x6f0 net/core/dev.c:6460 napi_poll net/core/dev.c:6527 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6660 __do_softirq+0x1d4/0x905 kernel/softirq.c:553 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 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/0/16: #0: ffffffff8c9a16c0 (rcu_read_lock){....}-{1:2}, at: __skb_unlink include/linux/skbuff.h:2363 [inline] #0: ffffffff8c9a16c0 (rcu_read_lock){....}-{1:2}, at: __skb_dequeue include/linux/skbuff.h:2378 [inline] #0: ffffffff8c9a16c0 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x23f/0x670 net/core/dev.c:5892 #1: ffffffff8c9a16c0 (rcu_read_lock){....}-{1:2}, at: can_receive+0x1ef/0x5c0 net/can/af_can.c:653 #2: ffff8880238935c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff8880238935c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x5f/0x4d0 net/can/j1939/socket.c:207 stack backtrace: CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.4.0-syzkaller-12415-g8fc3b8f082cc #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x2df/0x3b0 kernel/locking/lockdep.c:2195 check_prev_add kernel/locking/lockdep.c:3142 [inline] check_prevs_add kernel/locking/lockdep.c:3261 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726 __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:356 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1564 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x2bf/0x4d0 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline] j1939_session_completed+0xb6/0x170 net/can/j1939/transport.c:1222 j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1395 [inline] j1939_xtp_rx_eoma+0x2a1/0x680 net/can/j1939/transport.c:1410 j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline] j1939_tp_recv+0x71e/0xf50 net/can/j1939/transport.c:2144 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa80 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/0x5c0 net/can/af_can.c:663 can_rcv+0x1e1/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5452 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5566 process_backlog+0x101/0x670 net/core/dev.c:5894 __napi_poll+0xb7/0x6f0 net/core/dev.c:6460 napi_poll net/core/dev.c:6527 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6660 __do_softirq+0x1d4/0x905 kernel/softirq.c:553 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308