Hello, syzbot found the following issue on: HEAD commit: fac3cb82a54a net: bridge: mcast: use multicast_membership_.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=11554c0cb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=bab9d35f204746a7 dashboard link: https://syzkaller.appspot.com/bug?extid=f32cbede7fd867ce0d56 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f32cbede7fd867ce0d56@xxxxxxxxxxxxxxxxxxxxxxxxx vxcan0: j1939_tp_rxtimer: 0xffff888075703400: abort rx timeout. Force session deactivation ====================================================== WARNING: possible circular locking dependency detected 5.15.0-rc5-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/10231 is trying to acquire lock: ffff888035e15088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff888035e15088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff888035e15088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1554 but task is already holding lock: ffff88808959e5c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff88808959e5c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x56/0x460 net/can/j1939/socket.c:204 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:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_sk_queue_drop_all+0x40/0x2f0 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0x7b/0x160 net/can/j1939/socket.c:1272 j1939_netdev_notify+0x199/0x1d0 net/can/j1939/main.c:362 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1996 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1597 unregister_netdevice_many+0x3ff/0x1790 net/core/dev.c:11020 rtnl_delete_link net/core/rtnetlink.c:3063 [inline] rtnl_dellink+0x354/0xa80 net/core/rtnetlink.c:3115 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2510 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1935 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #1 (&priv->j1939_socks_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_sk_errqueue+0x9f/0x1a0 net/can/j1939/socket.c:1078 __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1124 j1939_session_cancel net/can/j1939/transport.c:1135 [inline] j1939_xtp_rx_dat_one+0xbc2/0xed0 net/can/j1939/transport.c:1907 j1939_xtp_rx_dat net/can/j1939/transport.c:1935 [inline] j1939_tp_recv+0x4ec/0xb40 net/can/j1939/transport.c:2108 j1939_can_recv+0x6d7/0x930 net/can/j1939/main.c:101 deliver net/can/af_can.c:574 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:608 can_receive+0x31d/0x580 net/can/af_can.c:665 can_rcv+0x120/0x1c0 net/can/af_can.c:696 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5436 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5550 process_backlog+0x2a5/0x6c0 net/core/dev.c:6427 __napi_poll+0xaf/0x440 net/core/dev.c:6986 napi_poll net/core/dev.c:7053 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7140 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:920 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (&priv->active_session_list_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1554 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x29b/0x460 net/can/j1939/socket.c:205 j1939_session_deactivate_activate_next+0x2e/0x35 net/can/j1939/transport.c:1101 j1939_tp_rxtimer+0xcc/0x36b net/can/j1939/transport.c:1228 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 mm_update_next_owner+0x341/0x7a0 kernel/exit.c:379 exit_mm kernel/exit.c:500 [inline] do_exit+0xab4/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae 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 *** 2 locks held by syz-executor.1/10231: #0: ffffffff8b60a098 (tasklist_lock){.+.+}-{2:2}, at: mm_update_next_owner+0x100/0x7a0 kernel/exit.c:367 #1: ffff88808959e5c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #1: ffff88808959e5c0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x56/0x460 net/can/j1939/socket.c:204 stack backtrace: CPU: 1 PID: 10231 Comm: syz-executor.1 Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __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:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x43/0x4b0 net/can/j1939/transport.c:1554 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x29b/0x460 net/can/j1939/socket.c:205 j1939_session_deactivate_activate_next+0x2e/0x35 net/can/j1939/transport.c:1101 j1939_tp_rxtimer+0xcc/0x36b net/can/j1939/transport.c:1228 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 </IRQ> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:mm_update_next_owner+0x341/0x7a0 kernel/exit.c:379 Code: a8 05 00 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 0f 85 5a 04 00 00 48 8b 85 a8 05 00 00 48 8d a8 48 fa ff ff 49 39 c6 75 32 eb 6c <e8> ba ee 30 00 48 8d bd b8 05 00 00 48 89 f8 48 c1 e8 03 80 3c 18 RSP: 0018:ffffc900041c7b40 EFLAGS: 00000207 RAX: 1ffff11005a9742a RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88801c113900 RSI: ffffffff8145e986 RDI: ffff88801c113e98 RBP: ffff88802d4b9c80 R08: 0000000000000001 R09: ffffffff8b60a083 R10: fffffbfff16c1410 R11: 0000000000000000 R12: ffff888090651500 R13: ffff88802d4ba150 R14: ffff888021c0a228 R15: ffff88801c113900 exit_mm kernel/exit.c:500 [inline] do_exit+0xab4/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4b967e3a39 Code: Unable to access opcode bytes at RIP 0x7f4b967e3a0f. RSP: 002b:00007f4b93d38188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: 0000000000000002 RBX: 00007f4b968e7020 RCX: 00007f4b967e3a39 RDX: 0492492492492627 RSI: 00000000200000c0 RDI: 0000000000000006 RBP: 00007f4b9683dc5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff9fcb162f R14: 00007f4b93d38300 R15: 0000000000022000 vxcan0: j1939_tp_rxtimer: 0xffff888078ce8000: rx timeout, send abort vxcan0: j1939_tp_rxtimer: 0xffff888078ce8000: abort rx timeout. Force session deactivation ---------------- Code disassembly (best guess): 0: a8 05 test $0x5,%al 2: 00 00 add %al,(%rax) 4: 4c 89 f0 mov %r14,%rax 7: 48 c1 e8 03 shr $0x3,%rax b: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) f: 0f 85 5a 04 00 00 jne 0x46f 15: 48 8b 85 a8 05 00 00 mov 0x5a8(%rbp),%rax 1c: 48 8d a8 48 fa ff ff lea -0x5b8(%rax),%rbp 23: 49 39 c6 cmp %rax,%r14 26: 75 32 jne 0x5a 28: eb 6c jmp 0x96 * 2a: e8 ba ee 30 00 callq 0x30eee9 <-- trapping instruction 2f: 48 8d bd b8 05 00 00 lea 0x5b8(%rbp),%rdi 36: 48 89 f8 mov %rdi,%rax 39: 48 c1 e8 03 shr $0x3,%rax 3d: 80 .byte 0x80 3e: 3c 18 cmp $0x18,%al --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
