[ 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 syzkaller login: [ 35.384277] IPVS: Creating netns size=2712 id=1 [ 35.390693] IPVS: ftp: loaded support on port[0] = 21 Warning: Permanently added '10.128.1.56' (ECDSA) to the list of known hosts. 2020/03/26 14:54:32 parsed 1 programs 2020/03/26 14:54:33 executed programs: 0 [ 43.381264] IPv6: ADDRCONF(NETDEV_CHANGE): nr2: link becomes ready [ 43.407959] IPv6: ADDRCONF(NETDEV_CHANGE): nr0: link becomes ready [ 43.425366] IPVS: Creating netns size=2712 id=2 [ 43.425515] IPVS: ftp: loaded support on port[0] = 21 [ 43.456506] IPv6: ADDRCONF(NETDEV_CHANGE): nr1: link becomes ready [ 43.465427] IPv6: ADDRCONF(NETDEV_CHANGE): nr4: link becomes ready [ 43.473802] IPv6: ADDRCONF(NETDEV_CHANGE): nr5: link becomes ready [ 43.488490] IPv6: ADDRCONF(NETDEV_CHANGE): nr3: link becomes ready [ 43.558441] IPVS: Creating netns size=2712 id=3 [ 43.563284] IPVS: ftp: loaded support on port[0] = 21 [ 43.708412] chnl_net:caif_netlink_parms(): no params data found [ 43.743099] IPVS: Creating netns size=2712 id=4 [ 43.748579] IPVS: ftp: loaded support on port[0] = 21 [ 43.942646] chnl_net:caif_netlink_parms(): no params data found [ 43.983671] IPVS: Creating netns size=2712 id=5 [ 43.989099] IPVS: ftp: loaded support on port[0] = 21 [ 44.075663] bridge0: port 1(bridge_slave_0) entered blocking state [ 44.082571] bridge0: port 1(bridge_slave_0) entered disabled state [ 44.092994] device bridge_slave_0 entered promiscuous mode [ 44.142042] bridge0: port 2(bridge_slave_1) entered blocking state [ 44.149158] bridge0: port 2(bridge_slave_1) entered disabled state [ 44.158926] device bridge_slave_1 entered promiscuous mode [ 44.232256] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 44.261621] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 44.369537] IPVS: Creating netns size=2712 id=6 [ 44.376043] IPVS: ftp: loaded support on port[0] = 21 [ 44.476840] bridge0: port 1(bridge_slave_0) entered blocking state [ 44.483398] bridge0: port 1(bridge_slave_0) entered disabled state [ 44.492801] device bridge_slave_0 entered promiscuous mode [ 44.500857] bridge0: port 2(bridge_slave_1) entered blocking state [ 44.508798] bridge0: port 2(bridge_slave_1) entered disabled state [ 44.517924] device bridge_slave_1 entered promiscuous mode [ 44.532068] chnl_net:caif_netlink_parms(): no params data found [ 44.667784] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 44.682210] batman_adv: Unable to register the batman interface 'batadv0': -12 [ 44.708994] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 44.723682] batman_adv: Unable to register the batman interface 'batadv0': -12 [ 44.789946] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 44.876060] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 44.931595] IPVS: Creating netns size=2712 id=7 [ 44.936550] IPVS: ftp: loaded support on port[0] = 21 [ 45.026692] chnl_net:caif_netlink_parms(): no params data found [ 45.113235] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 45.236832] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 45.262985] bridge0: port 1(bridge_slave_0) entered blocking state [ 45.270197] bridge0: port 1(bridge_slave_0) entered disabled state [ 45.279705] device bridge_slave_0 entered promiscuous mode [ 45.335369] bridge0: port 2(bridge_slave_1) entered blocking state [ 45.341800] bridge0: port 2(bridge_slave_1) entered disabled state [ 45.351365] device bridge_slave_1 entered promiscuous mode [ 45.403848] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 45.460768] chnl_net:caif_netlink_parms(): no params data found [ 45.476804] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 45.498591] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 45.512760] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 45.824075] bridge0: port 1(bridge_slave_0) entered blocking state [ 45.832892] bridge0: port 1(bridge_slave_0) entered disabled state [ 45.842792] device bridge_slave_0 entered promiscuous mode [ 45.851011] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 45.957452] bridge0: port 2(bridge_slave_1) entered blocking state [ 45.964963] bridge0: port 2(bridge_slave_1) entered disabled state [ 45.974738] device bridge_slave_1 entered promiscuous mode [ 45.981534] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 46.056446] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 46.148762] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 46.177884] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 46.206799] bridge0: port 1(bridge_slave_0) entered blocking state [ 46.213771] bridge0: port 1(bridge_slave_0) entered disabled state [ 46.222604] device bridge_slave_0 entered promiscuous mode [ 46.251185] chnl_net:caif_netlink_parms(): no params data found [ 46.279537] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 46.302267] bridge0: port 2(bridge_slave_1) entered blocking state [ 46.309310] bridge0: port 2(bridge_slave_1) entered disabled state [ 46.318723] device bridge_slave_1 entered promiscuous mode [ 46.428196] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 46.488554] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 46.501878] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 46.582884] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 46.749408] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready [ 46.891822] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 46.900272] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 46.920317] bridge0: port 1(bridge_slave_0) entered blocking state [ 46.927383] bridge0: port 1(bridge_slave_0) entered disabled state [ 46.937015] device bridge_slave_0 entered promiscuous mode [ 46.984100] bridge0: port 2(bridge_slave_1) entered blocking state [ 46.990607] bridge0: port 2(bridge_slave_1) entered disabled state [ 47.000280] device bridge_slave_1 entered promiscuous mode [ 47.007683] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready [ 47.061621] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready [ 47.096927] IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready [ 47.196009] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 47.225101] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready [ 47.257390] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 47.290943] IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready [ 47.307742] ------------[ cut here ]------------ [ 47.312657] WARNING: CPU: 0 PID: 5893 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x7b/0xa0 [ 47.321047] sysfs: cannot create duplicate filename '/class/macvtap/tap50' [ 47.328169] Kernel panic - not syncing: panic_on_warn set ... [ 47.328169] [ 47.335576] CPU: 0 PID: 5893 Comm: syz-executor.1 Not tainted 4.6.0-syzkaller #0 [ 47.343098] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.354256] 1ffffffff0d95756 ffff8800b9896fb0 ffffffff82c74fc6 ffffffff85c81040 [ 47.362309] ffff8800b9897088 ffffffff85d2bac0 ffffffff81922ccb ffff8800b9897078 [ 47.370666] ffffffff8160cf4e 0000000041b58ab3 ffffffff868f1f61 ffffffff8160cd9f [ 47.378952] Call Trace: [ 47.381528] [] dump_stack+0xe6/0x120 [ 47.387056] [] ? sysfs_warn_dup+0x7b/0xa0 [ 47.392857] [] panic+0x1af/0x348 [ 47.398238] [] ? set_ti_thread_flag+0xf/0xf [ 47.404205] [] ? sysfs_warn_dup+0x7b/0xa0 [ 47.409999] [] __warn+0x18d/0x1b0 [ 47.415221] [] warn_slowpath_fmt+0x92/0xb0 [ 47.421110] [] ? __warn+0x1b0/0x1b0 [ 47.426459] [] ? kernfs_path_from_node+0x4a/0x60 [ 47.433136] [] sysfs_warn_dup+0x7b/0xa0 [ 47.438893] [] sysfs_do_create_link_sd.isra.2+0xd1/0xf0 [ 47.446951] [] sysfs_create_link+0x43/0xb0 [ 47.452944] [] device_add+0x689/0x1360 [ 47.458466] [] ? device_private_init+0x180/0x180 [ 47.464850] [] ? kfree_const+0x1d/0x20 [ 47.470428] [] ? kobject_set_name_vargs+0xb4/0x130 [ 47.477216] [] device_create_groups_vargs+0x1c8/0x220 [ 47.484107] [] device_create+0x88/0xa0 [ 47.489830] [] ? device_create_vargs+0x20/0x20 [ 47.496092] [] ? macvlan_set_mac_address+0x150/0x150 [ 47.502836] [] macvtap_device_event+0x1c4/0x2a0 [ 47.509150] [] notifier_call_chain+0x8b/0x170 [ 47.515275] [] raw_notifier_call_chain+0x11/0x20 [ 47.522019] [] call_netdevice_notifiers_info+0x47/0x80 [ 47.528921] [] register_netdevice+0x88a/0xce0 [ 47.535048] [] ? netdev_change_features+0x80/0x80 [ 47.541513] [] ? kmem_cache_alloc_trace+0x34f/0x6b0 [ 47.548164] [] ? dev_get_nest_level+0x10c/0x1a0 [ 47.554596] [] macvlan_common_newlink+0x8b9/0x1090 [ 47.561166] [] macvtap_newlink+0xbf/0x110 [ 47.566946] [] ? __netlink_ns_capable+0xc7/0xf0 [ 47.573263] [] rtnl_newlink+0xd4b/0x1230 [ 47.578949] [] ? rtnl_link_ops_get+0x5d/0x90 [ 47.584992] [] ? rtnl_newlink+0x319/0x1230 [ 47.590855] [] ? load_balance+0x990/0x1ea0 [ 47.596802] [] ? rtnl_setlink+0x2f0/0x2f0 [ 47.603098] [] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 47.610094] [] ? __netlink_ns_capable+0xc7/0xf0 [ 47.616409] [] rtnetlink_rcv_msg+0x222/0x680 [ 47.622458] [] ? memset+0x28/0x30 [ 47.627685] [] ? rtnetlink_rcv+0x30/0x30 [ 47.633426] [] ? mutex_lock_nested+0x638/0xb30 [ 47.639721] [] ? rtnetlink_rcv+0x16/0x30 [ 47.645417] [] ? netlink_lookup+0xd4/0x630 [ 47.651287] [] netlink_rcv_skb+0x242/0x350 [ 47.657522] [] ? rtnetlink_rcv+0x30/0x30 [ 47.663317] [] rtnetlink_rcv+0x25/0x30 [ 47.668868] [] netlink_unicast+0x455/0x660 [ 47.674781] [] ? netlink_unicast+0x3b5/0x660 [ 47.681094] [] ? netlink_attachskb+0x730/0x730 [ 47.687406] [] netlink_sendmsg+0x893/0xb40 [ 47.693718] [] ? netlink_unicast+0x660/0x660 [ 47.699855] [] ? __might_fault+0xf1/0x1b0 [ 47.705733] [] ? security_socket_sendmsg+0x6a/0xa0 [ 47.712295] [] ? netlink_unicast+0x660/0x660 [ 47.719231] [] sock_sendmsg+0xb5/0xf0 [ 47.724934] [] SYSC_sendto+0x1c9/0x300 [ 47.730579] [] ? SYSC_connect+0x2a0/0x2a0 [ 47.736485] [] ? mnt_get_count+0x1c0/0x1c0 [ 47.742365] [] ? mntput_no_expire+0xb1/0x600 [ 47.748674] [] ? mntput_no_expire+0xce/0x600 [ 47.754937] [] ? mnt_get_count+0x1c0/0x1c0 [ 47.761270] [] ? mntput+0x52/0x70 [ 47.766865] [] ? ___might_sleep+0x331/0x440 [ 47.773441] [] ? trace_hardirqs_off+0xd/0x10 [ 47.779825] [] ? exit_to_usermode_loop+0xcb/0x1c0 [ 47.786733] [] ? trace_hardirqs_on_thunk+0x1b/0x1d [ 47.793629] [] SyS_sendto+0x9/0x10 [ 47.798848] [] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 47.806851] Kernel Offset: disabled