====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc4-syzkaller-00020-gf67dd6ce0723 #0 Not tainted ------------------------------------------------------ syz-executor.0/25415 is trying to acquire lock: ffff88804ec145c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff88804ec145c8 (&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: ffff88804b97d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff88804b97d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 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+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_errqueue+0x9f/0x1a0 net/can/j1939/socket.c:1081 __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1132 j1939_session_cancel net/can/j1939/transport.c:1143 [inline] j1939_xtp_rx_cts_one net/can/j1939/transport.c:1468 [inline] j1939_xtp_rx_cts+0xabc/0x11b0 net/can/j1939/transport.c:1481 j1939_tp_cmd_recv net/can/j1939/transport.c:2066 [inline] j1939_tp_recv+0xae8/0xcb0 net/can/j1939/transport.c:2141 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78a/0xa30 net/can/j1939/main.c:38 deliver net/can/af_can.c:573 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:607 can_receive+0x31d/0x580 net/can/af_can.c:664 can_rcv+0x162/0x1a0 net/can/af_can.c:688 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5489 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5603 process_backlog+0x3e0/0x810 net/core/dev.c:5931 __napi_poll+0xb8/0x770 net/core/dev.c:6498 napi_poll net/core/dev.c:6565 [inline] net_rx_action+0x9fc/0xde0 net/core/dev.c:6676 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 j1939_sk_send_loop net/can/j1939/socket.c:1143 [inline] j1939_sk_sendmsg+0xc94/0x13a0 net/can/j1939/socket.c:1256 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #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:355 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1561 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x1b2/0x450 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next+0xc8/0xd3 net/can/j1939/transport.c:1109 j1939_xtp_rx_abort_one.cold+0x20b/0x33c net/can/j1939/transport.c:1348 j1939_xtp_rx_abort net/can/j1939/transport.c:1359 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2108 [inline] j1939_tp_recv+0xb28/0xcb0 net/can/j1939/transport.c:2141 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78a/0xa30 net/can/j1939/main.c:38 deliver net/can/af_can.c:573 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:607 can_receive+0x31d/0x580 net/can/af_can.c:664 can_rcv+0x162/0x1a0 net/can/af_can.c:688 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5489 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5603 process_backlog+0x3e0/0x810 net/core/dev.c:5931 __napi_poll+0xb8/0x770 net/core/dev.c:6498 napi_poll net/core/dev.c:6565 [inline] net_rx_action+0x9fc/0xde0 net/core/dev.c:6676 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x645/0xa00 kernel/smpboot.c:164 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #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+0x1df/0x630 kernel/locking/lockdep.c:5633 __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:355 [inline] j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1275 j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:376 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] dev_close_many+0x2ff/0x630 net/core/dev.c:1545 unregister_netdevice_many+0x3fa/0x1930 net/core/dev.c:10821 rtnl_delete_link net/core/rtnetlink.c:3123 [inline] rtnl_dellink+0x354/0xa90 net/core/rtnetlink.c:3174 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6091 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 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.0/25415: #0: ffffffff8d7b7fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8d7b7fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e5/0xca0 net/core/rtnetlink.c:6088 #1: ffff88804b97d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] #1: ffff88804b97d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x28/0x160 net/can/j1939/socket.c:1269 stack backtrace: CPU: 3 PID: 25415 Comm: syz-executor.0 Not tainted 6.1.0-rc4-syzkaller-00020-gf67dd6ce0723 #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+0xcd/0x134 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+0x1df/0x630 kernel/locking/lockdep.c:5633 __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:355 [inline] j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1275 j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:376 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] dev_close_many+0x2ff/0x630 net/core/dev.c:1545 unregister_netdevice_many+0x3fa/0x1930 net/core/dev.c:10821 rtnl_delete_link net/core/rtnetlink.c:3123 [inline] rtnl_dellink+0x354/0xa90 net/core/rtnetlink.c:3174 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6091 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7f1a549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7f155cc EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000200002c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi