[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 17.522340] audit: type=1400 audit(1519203300.763:6): avc: denied { map } for pid=4156 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.15.193' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 syzkaller login: [ 24.023212] audit: type=1400 audit(1519203307.264:7): avc: denied { map } for pid=4170 comm="syzkaller679696" path="/root/syzkaller679696929" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 RTNETLINK answers: Operation not supported RTNETLINK answers: No buffer space available RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported [ 24.390763] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument executing program [ 24.718914] [ 24.720615] ===================================== [ 24.725427] WARNING: bad unlock balance detected! [ 24.730240] 4.16.0-rc2+ #323 Not tainted [ 24.734268] ------------------------------------- [ 24.739083] syzkaller679696/4170 is trying to release lock (rcu_read_lock_bh) at: [ 24.746683] [] hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 24.753665] but there are no more locks to release! [ 24.758647] [ 24.758647] other info that might help us debug this: [ 24.765283] 3 locks held by syzkaller679696/4170: [ 24.770090] #0: (&tfile->napi_mutex){+.+.}, at: [<00000000491c2332>] tun_get_user+0xe93/0x3810 [ 24.778992] #1: (rcu_read_lock){....}, at: [<00000000182c8f5d>] netif_receive_skb_internal+0xa2/0x670 [ 24.788504] #2: (rcu_read_lock){....}, at: [<000000000ddd2092>] ipv6_rcv+0x1446/0x1fa0 [ 24.796715] [ 24.796715] stack backtrace: [ 24.801182] CPU: 1 PID: 4170 Comm: syzkaller679696 Not tainted 4.16.0-rc2+ #323 [ 24.808597] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.817923] Call Trace: [ 24.821012] dump_stack+0x194/0x257 [ 24.824626] ? arch_local_irq_restore+0x53/0x53 [ 24.829283] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 24.834702] print_unlock_imbalance_bug+0x12f/0x140 [ 24.839689] lock_release+0x6fe/0xa40 [ 24.843460] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 24.848882] ? lock_downgrade+0x980/0x980 [ 24.853001] ? lock_release+0xa40/0xa40 [ 24.856951] ? __raw_spin_lock_init+0x1c/0x100 [ 24.861509] ? do_raw_spin_trylock+0x190/0x190 [ 24.866062] hashlimit_mt_common.isra.10+0x1c08/0x2610 [ 24.871310] ? dsthash_find+0x5b0/0x5b0 [ 24.875254] ? __lock_acquire+0x664/0x3e00 [ 24.879469] ? check_noncircular+0x20/0x20 [ 24.883680] ? __put_compound_page+0xc0/0xc0 [ 24.888061] ? lock_release+0xa40/0xa40 [ 24.892004] ? __bfs+0xaa/0x750 [ 24.895259] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 24.899982] ? lock_downgrade+0x980/0x980 [ 24.904103] hashlimit_mt+0x78/0x90 [ 24.907698] ? hashlimit_mt+0x78/0x90 [ 24.911470] ip6t_do_table+0x98d/0x1a30 [ 24.915412] ? is_bpf_text_address+0x7b/0x120 [ 24.919875] ? lock_downgrade+0x980/0x980 [ 24.923991] ? check_noncircular+0x20/0x20 [ 24.928199] ? ip6t_error+0x60/0x60 [ 24.931793] ? find_held_lock+0x35/0x1d0 [ 24.935821] ? check_noncircular+0x20/0x20 [ 24.940026] ? lock_acquire+0x1d5/0x580 [ 24.943968] ? lock_acquire+0x1d5/0x580 [ 24.947910] ? ipv6_rcv+0x1446/0x1fa0 [ 24.951681] ? lock_release+0xa40/0xa40 [ 24.955624] ip6table_raw_hook+0x65/0x80 [ 24.959658] nf_hook_slow+0xba/0x1a0 [ 24.963339] ipv6_rcv+0x1687/0x1fa0 [ 24.966937] ? ip6_rcv_finish+0x8c0/0x8c0 [ 24.971059] ? __lock_acquire+0x664/0x3e00 [ 24.975265] ? ip6_input+0x560/0x560 [ 24.978946] ? ip6_rcv_finish+0x8c0/0x8c0 [ 24.983063] __netif_receive_skb_core+0x1a41/0x3460 [ 24.988052] ? nf_ingress+0x9f0/0x9f0 [ 24.991830] ? __skb_flow_get_ports+0x3b0/0x420 [ 24.996471] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.001630] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.006788] ? print_irqtrace_events+0x270/0x270 [ 25.011516] ? check_noncircular+0x20/0x20 [ 25.015719] ? check_noncircular+0x20/0x20 [ 25.019923] ? lock_downgrade+0x980/0x980 [ 25.024042] ? check_noncircular+0x20/0x20 [ 25.028245] ? lock_release+0xa40/0xa40 [ 25.032190] ? is_bpf_text_address+0xa4/0x120 [ 25.036654] ? find_held_lock+0x35/0x1d0 [ 25.040689] ? print_irqtrace_events+0x270/0x270 [ 25.045416] ? netif_receive_skb_internal+0x1d7/0x670 [ 25.050575] ? lock_downgrade+0x980/0x980 [ 25.054694] ? pvclock_read_flags+0x160/0x160 [ 25.059157] ? mark_held_locks+0xaf/0x100 [ 25.063274] ? lock_acquire+0x1d5/0x580 [ 25.067215] ? lock_acquire+0x1d5/0x580 [ 25.071156] ? netif_receive_skb_internal+0xa2/0x670 [ 25.076231] ? ktime_get_with_offset+0x2c1/0x420 [ 25.080954] ? lock_release+0xa40/0xa40 [ 25.084894] ? do_gettimeofday+0x190/0x190 [ 25.089099] ? lock_release+0xa40/0xa40 [ 25.093041] __netif_receive_skb+0x2c/0x1b0 [ 25.097330] ? __netif_receive_skb+0x2c/0x1b0 [ 25.101793] netif_receive_skb_internal+0x10b/0x670 [ 25.106775] ? dev_cpu_dead+0xb00/0xb00 [ 25.110716] ? net_rx_action+0x1910/0x1910 [ 25.114923] ? eth_type_trans+0x2b2/0x710 [ 25.119039] ? eth_gro_receive+0x820/0x820 [ 25.123242] napi_gro_frags+0x58a/0xaf0 [ 25.127187] ? napi_gro_receive+0x500/0x500 [ 25.131481] ? tun_get_user+0x26f7/0x3810 [ 25.135598] tun_get_user+0x2720/0x3810 [ 25.139544] ? kernel_text_address+0x102/0x140 [ 25.144096] ? tun_build_skb.isra.50+0x1850/0x1850 [ 25.148995] ? xt_table_unlock+0x52/0x60 [ 25.153029] ? lock_downgrade+0x980/0x980 [ 25.157148] ? rawv6_setsockopt+0x4a/0xf0 [ 25.161266] ? SyS_setsockopt+0x189/0x360 [ 25.165385] ? do_syscall_64+0x280/0x940 [ 25.169418] ? tun_get+0x1ab/0x2e0 [ 25.172930] ? lock_release+0xa40/0xa40 [ 25.176874] ? __lock_is_held+0xb6/0x140 [ 25.180906] ? tun_get+0x1d4/0x2e0 [ 25.184413] ? tun_do_read+0x26c0/0x26c0 [ 25.188442] ? __check_object_size+0x8b/0x530 [ 25.192909] ? rcu_note_context_switch+0x710/0x710 [ 25.197806] tun_chr_write_iter+0xbd/0x1c0 [ 25.202015] do_iter_readv_writev+0x55c/0x830 [ 25.206485] ? vfs_dedupe_file_range+0x8f0/0x8f0 [ 25.211212] ? rw_verify_area+0xe5/0x2b0 [ 25.215241] do_iter_write+0x154/0x540 [ 25.219097] ? dup_iter+0x260/0x260 [ 25.222692] ? do_ip6t_set_ctl+0x104/0x5f0 [ 25.226896] vfs_writev+0x18a/0x340 [ 25.230491] ? vfs_iter_write+0xb0/0xb0 [ 25.234439] ? nf_setsockopt+0x93/0xc0 [ 25.238296] ? __fdget_pos+0x130/0x190 [ 25.242153] ? __fdget_raw+0x20/0x20 [ 25.245837] ? sock_common_setsockopt+0x95/0xd0 [ 25.250472] do_writev+0xfc/0x2a0 [ 25.253892] ? do_writev+0xfc/0x2a0 [ 25.257487] ? vfs_writev+0x340/0x340 [ 25.261260] ? mm_fault_error+0x2c0/0x2c0 [ 25.265386] ? move_addr_to_kernel+0x60/0x60 [ 25.269763] ? SyS_readv+0x30/0x30 [ 25.273272] SyS_writev+0x27/0x30 [ 25.276693] do_syscall_64+0x280/0x940 [ 25.280550] ? __do_page_fault+0xc90/0xc90 [ 25.284752] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.289478] ? syscall_return_slowpath+0x550/0x550 [ 25.294373] ? syscall_return_slowpath+0x2ac/0x550 [ 25.299279] ? prepare_exit_to_usermode+0x350/0x350 [ 25.304265] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 25.309597] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.314417] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.319573] RIP: 0033