[ OK ] Started Getty on tty3. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.235' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 29.545547] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 29.558385] IPVS: ftp: loaded support on port[0] = 21 executing program [ 29.589866] traps: syz-executor088[7966] trap stack segment ip:404548 sp:7fff6a0c27e0 error:0 [ 29.589908] syz-executor088[7987]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 29.589953] in syz-executor088869503[401000+83000] [ 29.618530] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 29.631312] IPVS: ftp: loaded support on port[0] = 21 executing program [ 29.662004] traps: syz-executor088[7988] trap stack segment ip:404548 sp:7fff6a0c27e0 error:0 in syz-executor088869503[401000+83000] [ 29.662050] syz-executor088[8009]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 29.690601] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 30.621842] IPVS: ftp: loaded support on port[0] = 21 [ 30.654453] syz-executor088[8010]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 executing program [ 30.664572] traps: syz-executor088[8031] trap stack segment ip:404548 sp:7fff6a0c27e0 error:0 in syz-executor088869503[401000+83000] [ 30.693779] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 31.559821] IPVS: ftp: loaded support on port[0] = 21 [ 31.593756] [ 31.595744] ====================================================== [ 31.602309] WARNING: possible circular locking dependency detected [ 31.609083] 4.14.230-syzkaller #0 Not tainted [ 31.614003] ------------------------------------------------------ [ 31.620542] syz-executor088/8032 is trying to acquire lock: [ 31.626883] (&xt[i].mutex){+.+.}, at: [] target_revfn+0x43/0x210 [ 31.635520] [ 31.635520] but task is already holding lock: [ 31.641870] (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 [ 31.650973] [ 31.650973] which lock already depends on the new lock. [ 31.650973] [ 31.659689] [ 31.659689] the existing dependency chain (in reverse order) is: [ 31.667617] [ 31.667617] -> #2 (&table[i].mutex){+.+.}: [ 31.673681] __mutex_lock+0xc4/0x1310 [ 31.678093] nf_tables_netdev_event+0x10d/0x4d0 [ 31.683471] notifier_call_chain+0x108/0x1a0 [ 31.689019] rollback_registered_many+0x765/0xba0 [ 31.694687] unregister_netdevice_many.part.0+0x18/0x2e0 [ 31.700849] unregister_netdevice_many+0x36/0x50 [ 31.706301] ip6gre_exit_net+0x41e/0x570 [ 31.710892] ops_exit_list+0xa5/0x150 [ 31.715314] cleanup_net+0x3b3/0x840 [ 31.720074] process_one_work+0x793/0x14a0 [ 31.724840] worker_thread+0x5cc/0xff0 [ 31.729254] kthread+0x30d/0x420 [ 31.733263] ret_from_fork+0x24/0x30 [ 31.737663] [ 31.737663] -> #1 (rtnl_mutex){+.+.}: [ 31.743021] __mutex_lock+0xc4/0x1310 [ 31.747712] unregister_netdevice_notifier+0x5e/0x2b0 [ 31.753553] tee_tg_destroy+0x5c/0xb0 [ 31.758012] cleanup_entry+0x232/0x310 [ 31.762599] __do_replace+0x38d/0x580 [ 31.767165] do_ip6t_set_ctl+0x256/0x3b0 [ 31.771905] nf_setsockopt+0x5f/0xb0 [ 31.776367] ipv6_setsockopt+0xc0/0x120 [ 31.781023] tcp_setsockopt+0x7b/0xc0 [ 31.785663] SyS_setsockopt+0x110/0x1e0 [ 31.790446] do_syscall_64+0x1d5/0x640 [ 31.795130] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 31.801806] [ 31.801806] -> #0 (&xt[i].mutex){+.+.}: [ 31.807361] lock_acquire+0x170/0x3f0 [ 31.811836] __mutex_lock+0xc4/0x1310 [ 31.816285] target_revfn+0x43/0x210 [ 31.820694] xt_find_revision+0x15e/0x1d0 [ 31.825427] nfnl_compat_get+0x1f7/0x870 [ 31.830407] nfnetlink_rcv_msg+0x9bb/0xc00 [ 31.835166] netlink_rcv_skb+0x125/0x390 [ 31.840243] nfnetlink_rcv+0x1ab/0x1da0 [ 31.844830] netlink_unicast+0x437/0x610 [ 31.849572] netlink_sendmsg+0x62e/0xb80 [ 31.854310] sock_sendmsg+0xb5/0x100 [ 31.858774] ___sys_sendmsg+0x6c8/0x800 [ 31.863402] __sys_sendmsg+0xa3/0x120 [ 31.868265] SyS_sendmsg+0x27/0x40 [ 31.872326] do_syscall_64+0x1d5/0x640 [ 31.877502] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 31.883317] [ 31.883317] other info that might help us debug this: [ 31.883317] [ 31.891906] Chain exists of: [ 31.891906] &xt[i].mutex --> rtnl_mutex --> &table[i].mutex [ 31.891906] [ 31.902543] Possible unsafe locking scenario: [ 31.902543] [ 31.908978] CPU0 CPU1 [ 31.913869] ---- ---- [ 31.918703] lock(&table[i].mutex); [ 31.922628] lock(rtnl_mutex); [ 31.928562] lock(&table[i].mutex); [ 31.935015] lock(&xt[i].mutex); [ 31.938602] [ 31.938602] *** DEADLOCK *** [ 31.938602] [ 31.944772] 1 lock held by syz-executor088/8032: [ 31.949661] #0: (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 [ 31.958789] [ 31.958789] stack backtrace: [ 31.963647] CPU: 0 PID: 8032 Comm: syz-executor088 Not tainted 4.14.230-syzkaller #0 [ 31.972009] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.981592] Call Trace: [ 31.984203] dump_stack+0x1b2/0x281 [ 31.988072] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 31.994548] __lock_acquire+0x2e0e/0x3f20 [ 31.998877] ? trace_hardirqs_on+0x10/0x10 [ 32.003293] ? __lock_acquire+0x5fc/0x3f20 [ 32.007766] lock_acquire+0x170/0x3f0 [ 32.011582] ? target_revfn+0x43/0x210 [ 32.015477] ? target_revfn+0x43/0x210 [ 32.019635] __mutex_lock+0xc4/0x1310 [ 32.023535] ? target_revfn+0x43/0x210 [ 32.027421] ? trace_hardirqs_on+0x10/0x10 [ 32.031754] ? target_revfn+0x43/0x210 [ 32.035926] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 32.041761] ? __lock_acquire+0x5fc/0x3f20 [ 32.046326] ? __lock_acquire+0x5fc/0x3f20 [ 32.050837] target_revfn+0x43/0x210 [ 32.054571] xt_find_revision+0x15e/0x1d0 [ 32.058818] ? match_revfn+0x210/0x210 [ 32.062719] ? deref_stack_reg+0x124/0x1a0 [ 32.066958] ? nfnetlink_rcv_msg+0x726/0xc00 [ 32.071403] nfnl_compat_get+0x1f7/0x870 [ 32.075793] ? nft_target_validate+0x240/0x240 [ 32.080842] ? nft_target_validate+0x240/0x240 [ 32.085512] nfnetlink_rcv_msg+0x9bb/0xc00 [ 32.089938] ? lock_downgrade+0x740/0x740 [ 32.094449] netlink_rcv_skb+0x125/0x390 [ 32.098614] ? nfnetlink_net_exit_batch+0x150/0x150 [ 32.103644] ? netlink_ack+0x9a0/0x9a0 [ 32.107804] ? ns_capable_common+0x127/0x150 [ 32.112218] nfnetlink_rcv+0x1ab/0x1da0 [ 32.116340] ? do_syscall_64+0x1d5/0x640 [ 32.120551] ? entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.126149] ? trace_hardirqs_on+0x10/0x10 [ 32.130391] ? __netlink_lookup+0x345/0x5d0 [ 32.135058] ? lock_downgrade+0x740/0x740 [ 32.139625] ? nfnetlink_bind+0x240/0x240 [ 32.144086] ? netlink_table_grab.part.0+0x1f0/0x1f0 [ 32.149328] ? netlink_deliver_tap+0x90/0x7d0 [ 32.154071] ? lock_downgrade+0x740/0x740 [ 32.158423] netlink_unicast+0x437/0x610 [ 32.162953] ? netlink_sendskb+0xd0/0xd0 [ 32.167021] ? __check_object_size+0x179/0x230 [ 32.172027] netlink_sendmsg+0x62e/0xb80 [ 32.176253] ? nlmsg_notify+0x170/0x170 [ 32.180388] ? kernel_recvmsg+0x210/0x210 [ 32.184610] ? security_socket_sendmsg+0x83/0xb0 [ 32.189821] ? nlmsg_notify+0x170/0x170 [ 32.193892] sock_sendmsg+0xb5/0x100 [ 32.197696] ___sys_sendmsg+0x6c8/0x800 [ 32.201916] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 32.207508] ? trace_hardirqs_on+0x10/0x10 [ 32.211808] ? trace_hardirqs_on+0x10/0x10 [ 32.216248] ? __fget+0x1fe/0x360 [ 32.219703] ? lock_acquire+0x170/0x3f0 [ 32.223701] ? lock_downgrade+0x740/0x740 [ 32.227874] ? __fget+0x225/0x360 [ 32.231622] ? __fdget+0x196/0x1f0 [ 32.235165] ? sockfd_lookup_light+0xb2/0x160 [ 32.239789] __sys_sendmsg+0xa3/0x120 [ 32.243652] ? SyS_shutdown+0x160/0x160 [ 32.247639] ? move_addr_to_kernel+0x60/0x60 [ 32.252251] ? __do_page_fault+0x159/0xad0 [ 32.256838] SyS_sendmsg+0x27/0x40 [ 32.260544] ? __sys_sendmsg+0x120/0x120 [ 32.264625] do_syscall_64+0x1d5/0x640 [ 32.268699] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 32.274210] RIP: 0033:0x440c99 [ 32.277969] RSP: 002b:00007fff6a0c2848 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 32.286377] RAX: ffffffffffffffda RBX: 0000000000007404 RCX: 0000000000440c99 [ 32.293900] RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000004 [ 32.301525] RBP: 0000000000000000 R08: 00007fff6a0c29e8 R09: 00007fff6a0c29e8 [ 32.308893] R10: 00007fff6a0c29e8 R11: 0000000000000246 R12: 00007fff6a0c285c [ 32.316467] R13: 431bde82d7b634db R14: 00000000004af018 R15: 0000000000400488 executing program [ 32.436026] syz-executor088[8032]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 32.450812] ip6_tables: ip6tables: counters copy to user failed while replacing table executing program [ 32.953077] IPVS: ftp: loaded support on port[0] = 21 [ 32.980756] syz-executor088[8057]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 33.006988] ip6_tables: ip6tables: counters copy to user failed while replacing table *** stack smashing detected ***: terminated executing program [ 33.663028] IPVS: ftp: loaded support on port[0] = 21 [ 33.694537] ip6_tables: ip6tables: counters copy to user failed while replacing table *** stack smashing detected ***: terminated executing program executing program [ 34.750495] IPVS: ftp: loaded support on port[0] = 21 [ 34.781728] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 34.794472] IPVS: ftp: loaded support on port[0] = 21 [ 34.830082] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 34.839858] syz-executor088[8144]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 35.451159] IPVS: ftp: loaded support on port[0] = 21 [ 35.479537] syz-executor088[8146]: segfault at 1 ip 0000000000000001 sp 00007fff6a0c27b8 error 14 [ 35.479554] syz-executor088[8167]: segfault at d ip 000000000000000d sp 00007fff6a0c2800 error 14 executing program [ 35.479563] in syz-executor088869503[400000+1000] [ 35.489301] in syz-executor088869503[400000+1000] [ 35.529337] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 36.141037] IPVS: ftp: loaded support on port[0] = 21 [ 36.170700] traps: syz-executor088[8191] trap stack segment ip:404548 sp:7fff6a0c27e0 error:0 in syz-executor088869503[401000+83000] executing program [ 36.170729] syz-executor088[8170]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 36.205817] ip6_tables: ip6tables: counters copy to user failed while replacing table executing program [ 36.820648] IPVS: ftp: loaded support on port[0] = 21 [ 36.848820] syz-executor088[8192]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 36.861947] ip6_tables: ip6tables: counters copy to user failed while replacing table *** stack smashing detected ***: terminated executing program [ 37.522756] IPVS: ftp: loaded support on port[0] = 21 [ 37.556699] ip6_tables: ip6tables: counters copy to user failed while replacing table *** stack smashing detected ***: terminated executing program [ 38.618323] IPVS: ftp: loaded support on port[0] = 21 [ 38.649087] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 38.660868] IPVS: ftp: loaded support on port[0] = 21 executing program [ 38.706458] syz-executor088[8258]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 38.721213] ip6_tables: ip6tables: counters copy to user failed while replacing table *** stack smashing detected ***: terminated executing program executing program [ 39.319539] IPVS: ftp: loaded support on port[0] = 21 [ 39.351257] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 39.363893] IPVS: ftp: loaded support on port[0] = 21 [ 39.400728] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 39.410809] syz-executor088[8324]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 executing program [ 40.549258] IPVS: ftp: loaded support on port[0] = 21 [ 40.586827] syz-executor088[8326]: segfault at 7fff6a0c29e8 ip 00007fff6a0c29e8 sp 00007fff6a0c2858 error 15 [ 40.601585] ip6_tables: ip6tables: counters copy to user failed while replacing table [ 41.215880] IPVS: ftp: loaded support on port[0] = 21 [ 41.244073] syz-executor088[8370]: segfault at 1 ip 0000000000000001 sp 00007fff6a0c27b8 error 14 in syz-executor088869503[400000+1000] executing program [ 41.244099] syz-executor088[8349]: segfault at d ip 000000000000000d sp 00007fff6a0c2800 error 14 in syz-executor088869503[400000+1000] [ 41.274689] ip6_tables: ip6tables: counters copy to user failed while replacing table