[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.183' (ECDSA) to the list of known hosts. 2020/06/26 11:27:18 fuzzer started 2020/06/26 11:27:18 dialing manager at 10.128.0.105:35077 2020/06/26 11:27:19 syscalls: 3105 2020/06/26 11:27:19 code coverage: enabled 2020/06/26 11:27:19 comparison tracing: enabled 2020/06/26 11:27:19 extra coverage: enabled 2020/06/26 11:27:19 setuid sandbox: enabled 2020/06/26 11:27:19 namespace sandbox: enabled 2020/06/26 11:27:19 Android sandbox: /sys/fs/selinux/policy does not exist 2020/06/26 11:27:19 fault injection: enabled 2020/06/26 11:27:19 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/06/26 11:27:19 net packet injection: enabled 2020/06/26 11:27:19 net device setup: enabled 2020/06/26 11:27:19 concurrency sanitizer: enabled 2020/06/26 11:27:19 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/06/26 11:27:19 USB emulation: enabled 2020/06/26 11:27:19 suppressing KCSAN reports in functions: 'kauditd_thread' '__ext4_new_inode' 'do_epoll_wait' 'futex_wait_queue_me' 'page_counter_charge' '__xa_clear_mark' 'blk_mq_sched_dispatch_requests' 11:27:23 executing program 0: r0 = socket(0x1000000010, 0x80002, 0x0) socketpair$unix(0x1, 0x1, 0x0, &(0x7f0000001840)={0xffffffffffffffff}) r2 = fcntl$dupfd(r1, 0x0, r1) r3 = socket$netlink(0x10, 0x3, 0x0) r4 = socket(0x10, 0x803, 0x0) sendmsg$NBD_CMD_DISCONNECT(r4, &(0x7f0000000280)={0x0, 0xfffffffffffffcfd, &(0x7f0000000180)={0x0}}, 0x0) getsockname$packet(r4, &(0x7f0000000100)={0x11, 0x0, 0x0, 0x1, 0x0, 0x6, @broadcast}, &(0x7f0000000200)=0x14) sendmsg$nl_route(r3, &(0x7f0000000040)={0x0, 0x0, &(0x7f0000000000)={&(0x7f0000000080)=ANY=[@ANYBLOB="480000001000050700"/20, @ANYRES32=r5, @ANYBLOB="0000000000000000280012000900010076657468"], 0x48}}, 0x0) sendmsg$nl_route_sched(0xffffffffffffffff, &(0x7f0000000240)={0x0, 0x0, &(0x7f0000000140)={&(0x7f00000003c0)=ANY=[@ANYBLOB="38000000240007050000004007a2a30005000000", @ANYRES32=r5, @ANYBLOB="00000000ffffffff00000000090001006866736300000000080002"], 0x38}}, 0x0) sendmsg$nl_route_sched(0xffffffffffffffff, &(0x7f00000001c0)={0x0, 0x0, &(0x7f0000000180)={&(0x7f0000000400)=@newtfilter={0x64, 0x2c, 0xd27, 0x0, 0x0, {0x0, 0x0, 0x0, r5, {}, {}, {0x2}}, [@filter_kind_options=@f_basic={{0xa, 0x1, 'basic\x00'}, {0x34, 0x2, [@TCA_BASIC_EMATCHES={0x30, 0x2, 0x0, 0x1, [@TCA_EMATCH_TREE_HDR={0x8, 0x1, {0x2e23}}, @TCA_EMATCH_TREE_LIST={0x24, 0x2, 0x0, 0x1, [@TCF_EM_META={0x20, 0x1, 0x0, 0x0, {{}, [@TCA_EM_META_HDR={0xc}, @TCA_EM_META_RVALUE={0x8, 0x3, [@TCF_META_TYPE_INT]}]}}]}]}]}}]}, 0x64}}, 0x0) ioctl$PERF_EVENT_IOC_ENABLE(r2, 0x8912, 0x400200) sendmmsg$alg(r0, &(0x7f0000000200), 0x4924924924926d3, 0x0) syzkaller login: [ 35.718153][ T8660] IPVS: ftp: loaded support on port[0] = 21 [ 35.781947][ T8660] chnl_net:caif_netlink_parms(): no params data found [ 35.814934][ T8660] bridge0: port 1(bridge_slave_0) entered blocking state [ 35.822351][ T8660] bridge0: port 1(bridge_slave_0) entered disabled state 11:27:23 executing program 1: r0 = open(&(0x7f0000000080)='./file0\x00', 0x1070c5, 0x0) r1 = open$dir(&(0x7f0000000380)='./file0\x00', 0x0, 0x0) write$9p(r0, &(0x7f0000001400)="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", 0x600) perf_event_open(&(0x7f0000000180)={0x2, 0x70, 0x95, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_bp={0x0}}, 0x0, 0x0, 0xffffffffffffffff, 0x0) ftruncate(0xffffffffffffffff, 0x0) sendfile(r0, r1, 0x0, 0x1c500) [ 35.830656][ T8660] device bridge_slave_0 entered promiscuous mode [ 35.838518][ T8660] bridge0: port 2(bridge_slave_1) entered blocking state [ 35.846614][ T8660] bridge0: port 2(bridge_slave_1) entered disabled state [ 35.854559][ T8660] device bridge_slave_1 entered promiscuous mode [ 35.869984][ T8660] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 35.880900][ T8660] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 35.897996][ T8660] team0: Port device team_slave_0 added [ 35.904729][ T8660] team0: Port device team_slave_1 added [ 35.918021][ T8660] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 35.925347][ T8660] 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. [ 35.952003][ T8660] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 35.964681][ T8660] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 35.971717][ T8660] 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. [ 36.006878][ T8660] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 36.022501][ T8815] IPVS: ftp: loaded support on port[0] = 21 11:27:24 executing program 2: r0 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) r1 = dup(r0) getpeername$packet(r1, 0x0, 0x0) [ 36.086458][ T8660] device hsr_slave_0 entered promiscuous mode [ 36.133190][ T8660] device hsr_slave_1 entered promiscuous mode [ 36.221206][ T8827] IPVS: ftp: loaded support on port[0] = 21 11:27:24 executing program 3: quotactl(0x40000080000102, 0x0, 0xee00, 0x0) [ 36.341555][ T8815] chnl_net:caif_netlink_parms(): no params data found [ 36.362513][ T8660] netdevsim netdevsim0 netdevsim0: renamed from eth0 [ 36.405270][ T8660] netdevsim netdevsim0 netdevsim1: renamed from eth1 [ 36.439810][ T8660] netdevsim netdevsim0 netdevsim2: renamed from eth2 [ 36.474843][ T8660] netdevsim netdevsim0 netdevsim3: renamed from eth3 11:27:24 executing program 4: r0 = syz_open_dev$usbfs(&(0x7f0000000840)='/dev/bus/usb/00#/00#\x00', 0x908, 0x1) socketpair$unix(0x1, 0x1, 0x0, &(0x7f0000000000)={0xffffffffffffffff, 0xffffffffffffffff}) ioctl$PERF_EVENT_IOC_ENABLE(r1, 0x8912, 0x400200) ioctl$USBDEVFS_SUBMITURB(r0, 0x8038550a, &(0x7f0000000040)=@urb_type_control={0x2, {}, 0x0, 0x5, &(0x7f0000000000)={0x0, 0x0, 0x0, 0x0, 0x8001}, 0xff1e, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}) [ 36.547218][ T8827] chnl_net:caif_netlink_parms(): no params data found [ 36.569210][ T9076] IPVS: ftp: loaded support on port[0] = 21 [ 36.615918][ T8660] bridge0: port 2(bridge_slave_1) entered blocking state [ 36.623022][ T8660] bridge0: port 2(bridge_slave_1) entered forwarding state [ 36.630301][ T8660] bridge0: port 1(bridge_slave_0) entered blocking state [ 36.637772][ T8660] bridge0: port 1(bridge_slave_0) entered forwarding state [ 36.676758][ T8815] bridge0: port 1(bridge_slave_0) entered blocking state [ 36.685655][ T8815] bridge0: port 1(bridge_slave_0) entered disabled state [ 36.693957][ T8815] device bridge_slave_0 entered promiscuous mode [ 36.716117][ T8815] bridge0: port 2(bridge_slave_1) entered blocking state [ 36.724592][ T8815] bridge0: port 2(bridge_slave_1) entered disabled state [ 36.732218][ T8815] device bridge_slave_1 entered promiscuous mode [ 36.749151][ T9120] IPVS: ftp: loaded support on port[0] = 21 [ 36.769940][ T8827] bridge0: port 1(bridge_slave_0) entered blocking state [ 36.778080][ T8827] bridge0: port 1(bridge_slave_0) entered disabled state [ 36.786632][ T8827] device bridge_slave_0 entered promiscuous mode [ 36.816487][ T5047] bridge0: port 1(bridge_slave_0) entered disabled state [ 36.824885][ T5047] bridge0: port 2(bridge_slave_1) entered disabled state [ 36.836991][ T8815] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 36.847256][ T8827] bridge0: port 2(bridge_slave_1) entered blocking state [ 36.855792][ T8827] bridge0: port 2(bridge_slave_1) entered disabled state [ 36.868074][ T8827] device bridge_slave_1 entered promiscuous mode 11:27:24 executing program 5: r0 = socket$nl_generic(0xa, 0x3, 0x10) setsockopt$netlink_NETLINK_RX_RING(r0, 0x29, 0x22, &(0x7f00000000c0)={0x1, 0x20001, 0x2}, 0x10) [ 36.894584][ T8815] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 36.912269][ T9076] chnl_net:caif_netlink_parms(): no params data found [ 36.938327][ T8827] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 36.985829][ T8815] team0: Port device team_slave_0 added [ 36.996786][ T8827] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 37.011443][ T9120] chnl_net:caif_netlink_parms(): no params data found [ 37.023040][ T8815] team0: Port device team_slave_1 added [ 37.050370][ T8815] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 37.057679][ T8815] 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. [ 37.084369][ T8815] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 37.097525][ T8660] 8021q: adding VLAN 0 to HW filter on device bond0 [ 37.107972][ T9370] IPVS: ftp: loaded support on port[0] = 21 [ 37.121014][ T8827] team0: Port device team_slave_0 added [ 37.127363][ T8815] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 37.134731][ T8815] 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. [ 37.160868][ T8815] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 37.179989][ T8827] team0: Port device team_slave_1 added [ 37.264080][ T8815] device hsr_slave_0 entered promiscuous mode [ 37.282550][ T8815] device hsr_slave_1 entered promiscuous mode [ 37.322318][ T8815] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 37.329909][ T8815] Cannot create hsr debugfs directory [ 37.337828][ T8827] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 37.344958][ T8827] 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. [ 37.371069][ T8827] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 37.393587][ T49] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 37.401522][ T49] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 37.416418][ T9076] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.424319][ T9076] bridge0: port 1(bridge_slave_0) entered disabled state [ 37.431854][ T9076] device bridge_slave_0 entered promiscuous mode [ 37.439680][ T9120] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.447339][ T9120] bridge0: port 1(bridge_slave_0) entered disabled state [ 37.459279][ T9120] device bridge_slave_0 entered promiscuous mode [ 37.472334][ T8827] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 37.479460][ T8827] 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. [ 37.506810][ T8827] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 37.525718][ T8660] 8021q: adding VLAN 0 to HW filter on device team0 [ 37.533371][ T9076] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.540482][ T9076] bridge0: port 2(bridge_slave_1) entered disabled state [ 37.548047][ T9076] device bridge_slave_1 entered promiscuous mode [ 37.557818][ T9120] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.566009][ T9120] bridge0: port 2(bridge_slave_1) entered disabled state [ 37.574236][ T9120] device bridge_slave_1 entered promiscuous mode [ 37.589722][ T9120] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 37.608124][ T9076] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 37.619099][ T9076] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 37.629114][ T9120] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 37.639746][ T5047] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 37.649495][ T5047] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 37.658000][ T5047] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.665333][ T5047] bridge0: port 1(bridge_slave_0) entered forwarding state [ 37.743553][ T8827] device hsr_slave_0 entered promiscuous mode [ 37.782348][ T8827] device hsr_slave_1 entered promiscuous mode [ 37.812026][ T8827] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 37.820030][ T8827] Cannot create hsr debugfs directory [ 37.839183][ T9120] team0: Port device team_slave_0 added [ 37.846986][ T49] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 37.856725][ T49] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 37.865206][ T49] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.872340][ T49] bridge0: port 2(bridge_slave_1) entered forwarding state [ 37.880809][ T49] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready [ 37.902699][ T3326] ================================================================== [ 37.910808][ T3326] BUG: KCSAN: data-race in copy_process / release_task [ 37.913795][ T8660] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network [ 37.917989][ T3326] [ 37.928347][ T8660] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network [ 37.930644][ T3326] write to 0xffffffff89281410 of 4 bytes by task 9557 on cpu 0: [ 37.948654][ T3326] release_task+0x6c8/0xb90 [ 37.953146][ T3326] do_exit+0x1140/0x16e0 [ 37.956818][ T8660] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 37.957559][ T3326] call_usermodehelper_exec_async+0x2da/0x2e0 [ 37.970609][ T3326] ret_from_fork+0x1f/0x30 [ 37.975006][ T3326] [ 37.977326][ T3326] read to 0xffffffff89281410 of 4 bytes by task 3326 on cpu 1: [ 37.984868][ T3326] copy_process+0xab5/0x32b0 [ 37.985530][ T8660] device veth0_vlan entered promiscuous mode [ 37.989454][ T3326] _do_fork+0xf1/0x660 [ 37.999480][ T3326] kernel_thread+0x85/0xb0 [ 38.000919][ T8660] device veth1_vlan entered promiscuous mode [ 38.003909][ T3326] call_usermodehelper_exec_work+0x4f/0x1b0 [ 38.003917][ T3326] process_one_work+0x3cb/0x990 [ 38.003924][ T3326] worker_thread+0x665/0xbe0 [ 38.003932][ T3326] kthread+0x210/0x220 [ 38.003942][ T3326] ret_from_fork+0x1f/0x30 [ 38.003949][ T3326] [ 38.022273][ T9120] team0: Port device team_slave_1 added [ 38.025278][ T3326] Reported by Kernel Concurrency Sanitizer on: [ 38.040418][ T9120] batman_adv: batadv0: Adding interface: batadv_slave_0 [ 38.041694][ T3326] CPU: 1 PID: 3326 Comm: kworker/u4:4 Not tainted 5.8.0-rc2-syzkaller #0 [ 38.048029][ T9120] 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. [ 38.054761][ T3326] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.054779][ T3326] Workqueue: events_unbound call_usermodehelper_exec_work [ 38.054783][ T3326] ================================================================== [ 38.054788][ T3326] Kernel panic - not syncing: panic_on_warn set ... [ 38.054799][ T3326] CPU: 1 PID: 3326 Comm: kworker/u4:4 Not tainted 5.8.0-rc2-syzkaller #0 [ 38.054804][ T3326] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.054814][ T3326] Workqueue: events_unbound call_usermodehelper_exec_work [ 38.054818][ T3326] Call Trace: [ 38.054833][ T3326] dump_stack+0x10f/0x19d [ 38.054847][ T3326] panic+0x1f8/0x63a [ 38.068448][ T9120] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active [ 38.089820][ T3326] ? vprintk_emit+0x44a/0x4f0 [ 38.089834][ T3326] kcsan_report+0x684/0x690 [ 38.089846][ T3326] ? kcsan_setup_watchpoint+0x453/0x4d0 [ 38.089855][ T3326] ? copy_process+0xab5/0x32b0 [ 38.089862][ T3326] ? _do_fork+0xf1/0x660 [ 38.089870][ T3326] ? kernel_thread+0x85/0xb0 [ 38.089888][ T3326] ? call_usermodehelper_exec_work+0x4f/0x1b0 [ 38.104539][ T9120] batman_adv: batadv0: Adding interface: batadv_slave_1 [ 38.108177][ T3326] ? process_one_work+0x3cb/0x990 [ 38.117446][ T9120] 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. [ 38.123226][ T3326] ? worker_thread+0x665/0xbe0 [ 38.123235][ T3326] ? kthread+0x210/0x220 [ 38.123247][ T3326] ? ret_from_fork+0x1f/0x30 [ 38.123271][ T3326] ? debug_smp_processor_id+0x18/0x20 [ 38.123281][ T3326] ? sysvec_hyperv_callback+0x90/0x140 [ 38.123295][ T3326] ? copy_creds+0x280/0x350 [ 38.134099][ T9120] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active [ 38.141924][ T3326] ? copy_creds+0x280/0x350 [ 38.141937][ T3326] kcsan_setup_watchpoint+0x453/0x4d0 [ 38.141947][ T3326] ? copy_creds+0x280/0x350 [ 38.141956][ T3326] copy_process+0xab5/0x32b0 [ 38.141972][ T3326] ? check_preempt_wakeup+0x1cb/0x370 [ 38.141983][ T3326] ? proc_cap_handler+0x280/0x280 [ 38.141996][ T3326] _do_fork+0xf1/0x660 [ 38.317649][ T3326] ? check_preemption_disabled+0x8f/0x1a0 [ 38.323628][ T3326] ? proc_cap_handler+0x280/0x280 [ 38.328653][ T3326] kernel_thread+0x85/0xb0 [ 38.333068][ T3326] ? proc_cap_handler+0x280/0x280 [ 38.338171][ T3326] call_usermodehelper_exec_work+0x4f/0x1b0 [ 38.344073][ T3326] process_one_work+0x3cb/0x990 [ 38.348917][ T3326] worker_thread+0x665/0xbe0 [ 38.353660][ T3326] ? finish_task_switch+0x8b/0x270 [ 38.358745][ T3326] ? process_one_work+0x990/0x990 [ 38.363756][ T3326] kthread+0x210/0x220 [ 38.367795][ T3326] ? process_one_work+0x990/0x990 [ 38.372806][ T3326] ? constant_test_bit+0x30/0x30 [ 38.377948][ T3326] ret_from_fork+0x1f/0x30 [ 38.384127][ T3326] Kernel Offset: disabled [ 38.388452][ T3326] Rebooting in 86400 seconds..