====================================================== WARNING: possible circular locking dependency detected 6.7.0-syzkaller-12829-g125514880ddd #0 Not tainted ------------------------------------------------------ syz-executor.4/11696 is trying to acquire lock: ffff88802124d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802124d0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0xaa/0x1a0 net/can/j1939/socket.c:1083 but task is already holding lock: ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x41/0x360 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+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+0x4b/0x4a0 net/can/j1939/transport.c:1564 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x2bc/0x4d0 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline] j1939_xtp_rx_abort_one+0x3ea/0x570 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+0xcf4/0xf50 net/can/j1939/transport.c:2144 j1939_can_recv+0x78b/0xa70 net/can/j1939/main.c:112 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x2a5/0x8e0 net/can/af_can.c:606 can_receive+0x320/0x5c0 net/can/af_can.c:663 can_rcv+0x1dc/0x270 net/can/af_can.c:687 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5534 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5648 process_backlog+0x101/0x6b0 net/core/dev.c:5976 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6778 __do_softirq+0x21a/0x8de kernel/softirq.c:553 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 -> #1 (&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:1282 j1939_netdev_notify+0x1a2/0x1d0 net/can/j1939/main.c:381 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x130 net/core/dev.c:1966 call_netdevice_notifiers_extack net/core/dev.c:2004 [inline] call_netdevice_notifiers net/core/dev.c:2018 [inline] __dev_notify_flags+0x1f5/0x2e0 net/core/dev.c:8689 dev_change_flags+0x10c/0x160 net/core/dev.c:8725 do_setlink+0x1aac/0x4080 net/core/rtnetlink.c:2903 rtnl_group_changelink net/core/rtnetlink.c:3452 [inline] __rtnl_newlink+0xe04/0x1940 net/core/rtnetlink.c:3711 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3748 rtnetlink_rcv_msg+0x3c7/0xe00 net/core/rtnetlink.c:6615 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1367 netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmsg+0x117/0x1e0 net/socket.c:2667 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x79/0x110 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a -> #0 (&priv->j1939_socks_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:3869 [inline] __lock_acquire+0x2445/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 __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+0xaa/0x1a0 net/can/j1939/socket.c:1083 j1939_session_destroy+0x276/0x4f0 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+0x28e/0x330 net/can/j1939/transport.c:1086 j1939_cancel_active_session+0x183/0x360 net/can/j1939/transport.c:2194 j1939_netdev_notify+0x19a/0x1d0 net/can/j1939/main.c:380 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x130 net/core/dev.c:1966 call_netdevice_notifiers_extack net/core/dev.c:2004 [inline] call_netdevice_notifiers net/core/dev.c:2018 [inline] __dev_notify_flags+0x1f5/0x2e0 net/core/dev.c:8689 dev_change_flags+0x10c/0x160 net/core/dev.c:8725 do_setlink+0x1aac/0x4080 net/core/rtnetlink.c:2903 rtnl_group_changelink net/core/rtnetlink.c:3452 [inline] __rtnl_newlink+0xe04/0x1940 net/core/rtnetlink.c:3711 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3748 rtnetlink_rcv_msg+0x3c7/0xe00 net/core/rtnetlink.c:6615 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1367 netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmsg+0x117/0x1e0 net/socket.c:2667 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x79/0x110 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a 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.4/11696: #0: ffffffff8ecc0b68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8ecc0b68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xe00 net/core/rtnetlink.c:6612 #1: ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] #1: ffff88802124d088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x41/0x360 net/can/j1939/transport.c:2183 stack backtrace: CPU: 1 PID: 11696 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller-12829-g125514880ddd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x317/0x400 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:3869 [inline] __lock_acquire+0x2445/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 __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+0xaa/0x1a0 net/can/j1939/socket.c:1083 j1939_session_destroy+0x276/0x4f0 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+0x28e/0x330 net/can/j1939/transport.c:1086 j1939_cancel_active_session+0x183/0x360 net/can/j1939/transport.c:2194 j1939_netdev_notify+0x19a/0x1d0 net/can/j1939/main.c:380 notifier_call_chain+0xb6/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x130 net/core/dev.c:1966 call_netdevice_notifiers_extack net/core/dev.c:2004 [inline] call_netdevice_notifiers net/core/dev.c:2018 [inline] __dev_notify_flags+0x1f5/0x2e0 net/core/dev.c:8689 dev_change_flags+0x10c/0x160 net/core/dev.c:8725 do_setlink+0x1aac/0x4080 net/core/rtnetlink.c:2903 rtnl_group_changelink net/core/rtnetlink.c:3452 [inline] __rtnl_newlink+0xe04/0x1940 net/core/rtnetlink.c:3711 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3748 rtnetlink_rcv_msg+0x3c7/0xe00 net/core/rtnetlink.c:6615 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1367 netlink_sendmsg+0x8b7/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmsg+0x117/0x1e0 net/socket.c:2667 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x79/0x110 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a RIP: 0023:0xf7f09579 Code: 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 00 00 00 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:00000000f7f045ac EFLAGS: 00000292 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000020006440 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), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi