====================================================== WARNING: possible circular locking dependency detected 6.1.38-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/28961 is trying to acquire lock: ffff00012ab3d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff00012ab3d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081 but task is already holding lock: ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x54/0x414 net/can/j1939/transport.c:2183 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&priv->active_session_list_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x54/0x6c 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+0x60/0x378 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_xtp_rx_abort_one+0x2e4/0x358 net/can/j1939/transport.c:1351 j1939_xtp_rx_abort net/can/j1939/transport.c:1362 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2111 [inline] j1939_tp_recv+0x814/0xe14 net/can/j1939/transport.c:2144 j1939_can_recv+0x5d0/0x948 net/can/j1939/main.c:112 deliver net/can/af_can.c:573 [inline] can_rcv_filter+0x308/0x714 net/can/af_can.c:607 can_receive+0x338/0x498 net/can/af_can.c:664 can_rcv+0x128/0x240 net/can/af_can.c:688 __netif_receive_skb_one_core net/core/dev.c:5496 [inline] __netif_receive_skb+0x18c/0x400 net/core/dev.c:5610 process_backlog+0x410/0x784 net/core/dev.c:5938 __napi_poll+0xb4/0x3f0 net/core/dev.c:6505 napi_poll net/core/dev.c:6572 [inline] net_rx_action+0x5cc/0xd3c net/core/dev.c:6683 __do_softirq+0x30c/0xea0 kernel/softirq.c:571 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:889 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84 invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x28c/0x534 kernel/softirq.c:650 irq_exit_rcu+0x14/0x84 kernel/softirq.c:662 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577 arch_local_irq_enable+0xc/0x18 arch/arm64/include/asm/irqflags.h:35 default_idle_call+0x68/0xdc kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1e0/0x514 kernel/sched/idle.c:303 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:400 rest_init+0x2d8/0x2f0 init/main.c:729 start_kernel+0x0/0x60c init/main.c:890 start_kernel+0x44c/0x60c init/main.c:1145 __primary_switched+0xb8/0xc0 arch/arm64/kernel/head.S:468 -> #1 (&jsk->sk_session_queue_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x54/0x6c kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [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:381 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8626 do_setlink+0xc70/0x3328 net/core/rtnetlink.c:2788 __rtnl_newlink net/core/rtnetlink.c:3553 [inline] rtnl_newlink+0x13b8/0x1b04 net/core/rtnetlink.c:3600 rtnetlink_rcv_msg+0x72c/0xd94 net/core/rtnetlink.c:6097 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2524 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6115 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline] netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1354 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1902 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x558/0x844 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&priv->j1939_socks_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x54/0x6c kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [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+0xf0/0x4b4 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:380 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8626 do_setlink+0xc70/0x3328 net/core/rtnetlink.c:2788 __rtnl_newlink net/core/rtnetlink.c:3553 [inline] rtnl_newlink+0x13b8/0x1b04 net/core/rtnetlink.c:3600 rtnetlink_rcv_msg+0x72c/0xd94 net/core/rtnetlink.c:6097 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2524 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6115 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline] netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1354 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1902 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x558/0x844 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Chain exists of: &priv->j1939_socks_lock --> &jsk->sk_session_queue_lock --> &priv->active_session_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&priv->active_session_list_lock); lock(&jsk->sk_session_queue_lock); lock(&priv->active_session_list_lock); lock(&priv->j1939_socks_lock); *** DEADLOCK *** 2 locks held by syz-executor.0/28961: #0: ffff800017b9e948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffff800017b9e948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e8/0xd94 net/core/rtnetlink.c:6094 #1: ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] #1: ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] #1: ffff00012ab3d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x54/0x414 net/can/j1939/transport.c:2183 stack backtrace: CPU: 1 PID: 28961 Comm: syz-executor.0 Not tainted 6.1.38-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x54/0x6c kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [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+0xf0/0x4b4 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:380 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8626 do_setlink+0xc70/0x3328 net/core/rtnetlink.c:2788 __rtnl_newlink net/core/rtnetlink.c:3553 [inline] rtnl_newlink+0x13b8/0x1b04 net/core/rtnetlink.c:3600 rtnetlink_rcv_msg+0x72c/0xd94 net/core/rtnetlink.c:6097 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2524 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6115 netlink_unicast_kernel net/netlink/af_netlink.c:1328 [inline] netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1354 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1902 sock_sendmsg_nosec net/socket.c:716 [inline] sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x558/0x844 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581