[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.81' (ECDSA) to the list of known hosts. syzkaller login: [ 56.124686][ T6828] IPVS: ftp: loaded support on port[0] = 21 [ 56.211576][ T6828] chnl_net:caif_netlink_parms(): no params data found [ 56.263200][ T6828] bridge0: port 1(bridge_slave_0) entered blocking state [ 56.270599][ T6828] bridge0: port 1(bridge_slave_0) entered disabled state [ 56.278731][ T6828] device bridge_slave_0 entered promiscuous mode [ 56.287667][ T6828] bridge0: port 2(bridge_slave_1) entered blocking state [ 56.294779][ T6828] bridge0: port 2(bridge_slave_1) entered disabled state [ 56.303483][ T6828] device bridge_slave_1 entered promiscuous mode [ 56.323295][ T6828] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 56.334718][ T6828] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 56.357409][ T6828] team0: Port device team_slave_0 added [ 56.364595][ T6828] team0: Port device team_slave_1 added [ 56.381476][ T6828] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 56.388517][ T6828] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. [ 56.414454][ T6828] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 56.426921][ T6828] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 56.434053][ T6828] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. [ 56.460012][ T6828] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 56.521483][ T6828] device hsr_slave_0 entered promiscuous mode [ 56.577506][ T6828] device hsr_slave_1 entered promiscuous mode [ 56.690749][ T6828] netdevsim netdevsim0 netdevsim0: renamed from eth0 [ 56.750044][ T6828] netdevsim netdevsim0 netdevsim1: renamed from eth1 [ 56.818932][ T6828] netdevsim netdevsim0 netdevsim2: renamed from eth2 [ 56.858776][ T6828] netdevsim netdevsim0 netdevsim3: renamed from eth3 [ 56.912231][ T6828] bridge0: port 2(bridge_slave_1) entered blocking state [ 56.919453][ T6828] bridge0: port 2(bridge_slave_1) entered forwarding state [ 56.927452][ T6828] bridge0: port 1(bridge_slave_0) entered blocking state [ 56.934525][ T6828] bridge0: port 1(bridge_slave_0) entered forwarding state [ 56.977431][ T6828] 8021q: adding VLAN 0 to HW filter on device bond0 [ 56.992795][ T2508] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 57.002300][ T2508] bridge0: port 1(bridge_slave_0) entered disabled state [ 57.011431][ T2508] bridge0: port 2(bridge_slave_1) entered disabled state [ 57.020100][ T2508] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 57.033603][ T6828] 8021q: adding VLAN 0 to HW filter on device team0 [ 57.044449][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 57.053555][ T3855] bridge0: port 1(bridge_slave_0) entered blocking state [ 57.060705][ T3855] bridge0: port 1(bridge_slave_0) entered forwarding state [ 57.073222][ T2497] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 57.082151][ T2497] bridge0: port 2(bridge_slave_1) entered blocking state [ 57.089279][ T2497] bridge0: port 2(bridge_slave_1) entered forwarding state [ 57.108746][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 57.127398][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 57.135462][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 57.145078][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 57.153691][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 57.163538][ T6828] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 57.182212][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready [ 57.190280][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready [ 57.204782][ T6828] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 57.224023][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready [ 57.234026][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready [ 57.256406][ T6828] device veth0_vlan entered promiscuous mode [ 57.263119][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready [ 57.272633][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready [ 57.281923][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready [ 57.292503][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready [ 57.309715][ T6828] device veth1_vlan entered promiscuous mode [ 57.331390][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready [ 57.340099][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready [ 57.348895][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready [ 57.357996][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready [ 57.368777][ T6828] device veth0_macvtap entered promiscuous mode [ 57.379513][ T6828] device veth1_macvtap entered promiscuous mode [ 57.395887][ T6828] batman_adv: batadv0: Interface activated: batadv_slave_0 [ 57.403391][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready [ 57.413911][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready [ 57.422377][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready [ 57.431546][ T2507] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready [ 57.445063][ T6828] batman_adv: batadv0: Interface activated: batadv_slave_1 [ 57.455896][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready [ 57.464818][ T3855] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready [ 57.477358][ T6828] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0 [ 57.486142][ T6828] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0 [ 57.495128][ T6828] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0 [ 57.505021][ T6828] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 executing program [ 58.791234][ T6828] [ 58.793605][ T6828] ============================================ [ 58.799747][ T6828] WARNING: possible recursive locking detected [ 58.805890][ T6828] 5.8.0-rc6-syzkaller #0 Not tainted [ 58.811160][ T6828] -------------------------------------------- [ 58.817337][ T6828] syz-executor104/6828 is trying to acquire lock: [ 58.823769][ T6828] ffff8880a90c1098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x215e/0x2d60 [ 58.833160][ T6828] [ 58.833160][ T6828] but task is already holding lock: [ 58.840519][ T6828] ffff88809a0af498 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x25c/0xc00 [ 58.849582][ T6828] [ 58.849582][ T6828] other info that might help us debug this: [ 58.857641][ T6828] Possible unsafe locking scenario: [ 58.857641][ T6828] [ 58.865089][ T6828] CPU0 [ 58.868354][ T6828] ---- [ 58.871610][ T6828] lock(_xmit_ETHER#2); [ 58.875842][ T6828] lock(_xmit_ETHER#2); [ 58.880059][ T6828] [ 58.880059][ T6828] *** DEADLOCK *** [ 58.880059][ T6828] [ 58.888179][ T6828] May be due to missing lock nesting notation [ 58.888179][ T6828] [ 58.896672][ T6828] 10 locks held by syz-executor104/6828: [ 58.902302][ T6828] #0: ffffffff89bc0ec0 (rcu_read_lock){....}-{1:2}, at: rawv6_sendmsg+0x1dda/0x38f0 [ 58.911758][ T6828] #1: ffffffff89bc0e60 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x190/0x17b0 [ 58.921815][ T6828] #2: ffffffff89bc0e60 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1da/0x2d60 [ 58.931718][ T6828] #3: ffff888088c27258 (&sch->seqlock){+...}-{2:2}, at: __dev_queue_xmit+0x1310/0x2d60 [ 58.941434][ T6828] #4: ffff888088c27148 (dev->qdisc_running_key ?: &qdisc_running_key){+...}-{0:0}, at: neigh_resolve_output+0x3fe/0x6a0 [ 58.954011][ T6828] #5: ffff88809a0af498 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x25c/0xc00 [ 58.963473][ T6828] #6: ffff8880a6182860 (k-slock-AF_INET6){+...}-{2:2}, at: icmp6_send+0xe82/0x2660 [ 58.972839][ T6828] #7: ffffffff89bc0ec0 (rcu_read_lock){....}-{1:2}, at: icmp6_send+0x1453/0x2660 [ 58.982026][ T6828] #8: ffffffff89bc0e60 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x190/0x17b0 [ 58.992122][ T6828] #9: ffffffff89bc0e60 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1da/0x2d60 [ 59.002023][ T6828] [ 59.002023][ T6828] stack backtrace: [ 59.007913][ T6828] CPU: 1 PID: 6828 Comm: syz-executor104 Not tainted 5.8.0-rc6-syzkaller #0 [ 59.016584][ T6828] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.026622][ T6828] Call Trace: [ 59.029907][ T6828] dump_stack+0x18f/0x20d [ 59.034216][ T6828] __lock_acquire.cold+0x178/0x3f8 [ 59.039411][ T6828] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 59.045397][ T6828] ? skb_crc32c_csum_help+0x70/0x70 [ 59.050587][ T6828] lock_acquire+0x1f1/0xad0 [ 59.055179][ T6828] ? __dev_queue_xmit+0x215e/0x2d60 [ 59.060386][ T6828] ? lock_release+0x8d0/0x8d0 [ 59.065041][ T6828] ? validate_xmit_xfrm+0x4fe/0x1030 [ 59.070304][ T6828] ? lock_release+0x8d0/0x8d0 [ 59.074960][ T6828] ? validate_xmit_skb+0x848/0xe60 [ 59.080051][ T6828] _raw_spin_lock+0x2a/0x40 [ 59.084543][ T6828] ? __dev_queue_xmit+0x215e/0x2d60 [ 59.089720][ T6828] __dev_queue_xmit+0x215e/0x2d60 [ 59.094724][ T6828] ? neigh_resolve_output+0x2ec/0x6a0 [ 59.100076][ T6828] ? find_held_lock+0x2d/0x110 [ 59.104907][ T6828] ? netdev_core_pick_tx+0x2e0/0x2e0 [ 59.110174][ T6828] ? mark_held_locks+0x9f/0xe0 [ 59.114931][ T6828] ? read_seqcount_begin+0xdf/0x270 [ 59.120106][ T6828] ? memcpy+0x39/0x60 [ 59.124067][ T6828] neigh_resolve_output+0x3fe/0x6a0 [ 59.129265][ T6828] ip6_finish_output2+0x8b6/0x17b0 [ 59.134355][ T6828] __ip6_finish_output+0x447/0xab0 [ 59.139446][ T6828] ip6_finish_output+0x34/0x1f0 [ 59.144273][ T6828] ip6_output+0x1db/0x520 [ 59.148596][ T6828] ip6_local_out+0xaf/0x1a0 [ 59.153076][ T6828] ip6_send_skb+0xb7/0x340 [ 59.157483][ T6828] ip6_push_pending_frames+0xbd/0xe0 [ 59.162746][ T6828] icmpv6_push_pending_frames+0x294/0x470 [ 59.168443][ T6828] icmp6_send+0x1cec/0x2660 [ 59.172925][ T6828] ? icmpv6_push_pending_frames+0x470/0x470 [ 59.178840][ T6828] ? lock_acquire+0x1f1/0xad0 [ 59.183507][ T6828] ? ip6_neigh_lookup+0x31e/0x4d0 [ 59.188509][ T6828] ? mark_held_locks+0x9f/0xe0 [ 59.193251][ T6828] ? __local_bh_enable_ip+0x159/0x250 [ 59.198615][ T6828] ? ip6_neigh_lookup+0x356/0x4d0 [ 59.203616][ T6828] ? ip6_dst_destroy+0x280/0x280 [ 59.208541][ T6828] ? __ip6_route_redirect+0xb50/0xb50 [ 59.213899][ T6828] ? ip6_link_failure+0x29/0x510 [ 59.218813][ T6828] ip6_link_failure+0x29/0x510 [ 59.223563][ T6828] ? __ip6_route_redirect+0xb50/0xb50 [ 59.228967][ T6828] ip_tunnel_xmit+0x15cc/0x2ac3 [ 59.233821][ T6828] ? ip_md_tunnel_xmit+0x15b0/0x15b0 [ 59.239090][ T6828] ? lockdep_hardirqs_on_prepare+0x4ef/0x590 [ 59.245049][ T6828] ? skb_push+0x97/0xc0 [ 59.249193][ T6828] ? __gre_xmit+0x535/0x8f0 [ 59.253688][ T6828] erspan_xmit+0x1109/0x2760 [ 59.258273][ T6828] dev_hard_start_xmit+0x193/0x950 [ 59.263372][ T6828] sch_direct_xmit+0x2ea/0xc00 [ 59.268119][ T6828] ? pfifo_fast_enqueue+0xf3/0x5f0 [ 59.273208][ T6828] ? dev_watchdog+0xc80/0xc80 [ 59.277865][ T6828] ? pfifo_fast_dequeue+0x5a1/0xb20 [ 59.283042][ T6828] ? lock_is_held_type+0xb0/0xe0 [ 59.288136][ T6828] __qdisc_run+0x4b9/0x1630 [ 59.292648][ T6828] __dev_queue_xmit+0x1456/0x2d60 [ 59.297660][ T6828] ? neigh_resolve_output+0x2ec/0x6a0 [ 59.303022][ T6828] ? find_held_lock+0x2d/0x110 [ 59.307797][ T6828] ? netdev_core_pick_tx+0x2e0/0x2e0 [ 59.313076][ T6828] ? read_seqcount_begin+0xdf/0x270 [ 59.318253][ T6828] ? memcpy+0x39/0x60 [ 59.322215][ T6828] neigh_resolve_output+0x3fe/0x6a0 [ 59.327392][ T6828] ip6_finish_output2+0x8b6/0x17b0 [ 59.332478][ T6828] __ip6_finish_output+0x447/0xab0 [ 59.337581][ T6828] ip6_finish_output+0x34/0x1f0 [ 59.342424][ T6828] ip6_output+0x1db/0x520 [ 59.346840][ T6828] rawv6_sendmsg+0x2008/0x38f0 [ 59.351597][ T6828] ? rawv6_bind+0x9a0/0x9a0 [ 59.356106][ T6828] ? aa_profile_af_perm+0x2e0/0x2e0 [ 59.361284][ T6828] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 59.367242][ T6828] ? rawv6_recvmsg+0xd50/0xd50 [ 59.371984][ T6828] ? lock_is_held_type+0xb0/0xe0 [ 59.376901][ T6828] ? find_held_lock+0x2d/0x110 [ 59.381641][ T6828] ? aa_file_perm+0x5b8/0x1100 [ 59.386396][ T6828] inet_sendmsg+0x99/0xe0 [ 59.390702][ T6828] ? inet_send_prepare+0x4d0/0x4d0 [ 59.395787][ T6828] sock_sendmsg+0xcf/0x120 [ 59.400182][ T6828] sock_write_iter+0x28c/0x3c0 [ 59.404935][ T6828] ? sock_sendmsg+0x120/0x120 [ 59.409588][ T6828] ? aa_path_link+0x2f0/0x2f0 [ 59.414245][ T6828] ? lock_downgrade+0x820/0x820 [ 59.419093][ T6828] new_sync_write+0x422/0x650 [ 59.423764][ T6828] ? new_sync_read+0x6e0/0x6e0 [ 59.428516][ T6828] ? ip6_datagram_connect_v6_only+0x78/0xa0 [ 59.434421][ T6828] ? __local_bh_enable_ip+0x159/0x250 [ 59.439777][ T6828] ? apparmor_file_permission+0x26e/0x4e0 [ 59.445489][ T6828] vfs_write+0x59d/0x6b0 [ 59.449732][ T6828] ksys_write+0x1ee/0x250 [ 59.454057][ T6828] ? __ia32_sys_read+0xb0/0xb0 [ 59.458888][ T6828] ? lock_is_held_type+0xb0/0xe0 [ 59.463807][ T6828] ? do_syscall_64+0x1c/0xe0 [ 59.468470][ T6828] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 59.474447][ T6828] do_syscall_64+0x60/0xe0 [ 59.478849][ T6828] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 59.484722][ T6828] RIP: 0033:0x449609 [ 59.488602][ T6828] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 0c fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 59.508288][ T6828] RSP: 002b:00007fffca342858 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 59.516692][ T6828] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000449609 [ 59.524651][ T6828] RDX: 0000000000000028 RSI: 0000000020000140 RDI: 0000000000000005 [ 59.532602][ T6828] RBP: 00007fffca3428e0 R08: 0000000000000000 R09: 0000000000000000 [ 59.540565][ T6828] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffca3428c0 [ 59.548538][ T6828] R13: 0000000000000004 R14: 00000000015d2850 R15: 0000000000000003