[....] Starting enhanced syslogd: rsyslogd[ 16.247422] audit: type=1400 audit(1519109796.705:5): avc: denied { syslog } for pid=4006 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?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. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.563151] audit: type=1400 audit(1519109803.020:6): avc: denied { map } for pid=4147 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 Warning: Permanently added '10.128.15.196' (ECDSA) to the list of known hosts. [ 28.917415] audit: type=1400 audit(1519109809.375:7): avc: denied { map } for pid=4161 comm="syz-execprog" path="/root/syz-execprog" dev="sda1" ino=16479 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 2018/02/20 06:56:49 parsed 1 programs 2018/02/20 06:56:49 executed programs: 0 [ 29.162141] audit: type=1400 audit(1519109809.619:8): avc: denied { map } for pid=4161 comm="syz-execprog" path="/root/syzkaller-shm425023044" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 [ 29.171524] IPVS: ftp: loaded support on port[0] = 21 [ 29.397752] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready [ 29.707470] [ 29.709108] ===================================== [ 29.713918] WARNING: bad unlock balance detected! [ 29.718728] 4.16.0-rc1+ #232 Not tainted [ 29.722752] ------------------------------------- [ 29.727558] syz-executor0/4295 is trying to release lock (rcu_read_lock_bh) at: [ 29.734986] [] hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 29.741963] but there are no more locks to release! [ 29.746943] [ 29.746943] other info that might help us debug this: [ 29.753582] 3 locks held by syz-executor0/4295: [ 29.758214] #0: (&tfile->napi_mutex){+.+.}, at: [<0000000015600dfa>] tun_get_user+0xe6c/0x3940 [ 29.767110] #1: (rcu_read_lock){....}, at: [<00000000bb0071af>] netif_receive_skb_internal+0xa2/0x670 [ 29.776622] #2: (rcu_read_lock){....}, at: [<00000000f61ecabf>] ipv6_rcv+0x1446/0x1fa0 [ 29.784821] [ 29.784821] stack backtrace: [ 29.789283] CPU: 0 PID: 4295 Comm: syz-executor0 Not tainted 4.16.0-rc1+ #232 [ 29.796526] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.805855] Call Trace: [ 29.808411] dump_stack+0x194/0x257 [ 29.812003] ? arch_local_irq_restore+0x53/0x53 [ 29.816642] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 29.822060] print_unlock_imbalance_bug+0x12f/0x140 [ 29.827052] lock_release+0x6fe/0xa40 [ 29.830818] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 29.836234] ? lock_downgrade+0x980/0x980 [ 29.840352] ? lock_release+0xa40/0xa40 [ 29.844293] ? __raw_spin_lock_init+0x1c/0x100 [ 29.848841] ? do_raw_spin_trylock+0x190/0x190 [ 29.853393] hashlimit_mt_common.isra.10+0x1c08/0x2610 [ 29.858635] ? lockdep_on+0x50/0x50 [ 29.862234] ? dsthash_find+0x5b0/0x5b0 [ 29.866177] ? __lock_acquire+0x664/0x3e00 [ 29.870378] ? check_noncircular+0x20/0x20 [ 29.874583] ? lock_release+0xa40/0xa40 [ 29.878523] ? __bfs+0xaa/0x750 [ 29.881774] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 29.886496] ? lock_downgrade+0x980/0x980 [ 29.890611] hashlimit_mt+0x78/0x90 [ 29.894204] ? hashlimit_mt+0x78/0x90 [ 29.897973] ip6t_do_table+0x98d/0x1a30 [ 29.901915] ? is_bpf_text_address+0x7b/0x120 [ 29.906378] ? lock_downgrade+0x980/0x980 [ 29.910491] ? __bfs+0xaa/0x750 [ 29.913736] ? check_noncircular+0x20/0x20 [ 29.917939] ? ip6t_error+0x60/0x60 [ 29.921531] ? find_held_lock+0x35/0x1d0 [ 29.925560] ? check_noncircular+0x20/0x20 [ 29.929763] ? lock_acquire+0x1d5/0x580 [ 29.933705] ? lock_acquire+0x1d5/0x580 [ 29.937645] ? ipv6_rcv+0x1446/0x1fa0 [ 29.941412] ? lock_release+0xa40/0xa40 [ 29.945355] ip6table_raw_hook+0x65/0x80 [ 29.949383] nf_hook_slow+0xba/0x1a0 [ 29.953066] ipv6_rcv+0x1687/0x1fa0 [ 29.956661] ? ip6_rcv_finish+0x8c0/0x8c0 [ 29.960777] ? __lock_acquire+0x664/0x3e00 [ 29.964979] ? ip6_input+0x560/0x560 [ 29.968660] ? ip6_rcv_finish+0x8c0/0x8c0 [ 29.972774] __netif_receive_skb_core+0x1a41/0x3460 [ 29.977756] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.982915] ? nf_ingress+0x9f0/0x9f0 [ 29.986685] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.991843] ? print_irqtrace_events+0x270/0x270 [ 29.996566] ? check_noncircular+0x20/0x20 [ 30.000766] ? lock_downgrade+0x980/0x980 [ 30.004969] ? check_noncircular+0x20/0x20 [ 30.009171] ? lock_release+0xa40/0xa40 [ 30.013116] ? find_held_lock+0x35/0x1d0 [ 30.017145] ? print_irqtrace_events+0x270/0x270 [ 30.021867] ? lock_downgrade+0x980/0x980 [ 30.025984] ? pvclock_read_flags+0x160/0x160 [ 30.030537] ? mark_held_locks+0xaf/0x100 [ 30.034653] ? lock_acquire+0x1d5/0x580 [ 30.038592] ? lock_acquire+0x1d5/0x580 [ 30.042531] ? netif_receive_skb_internal+0xa2/0x670 [ 30.047601] ? ktime_get_with_offset+0x2c1/0x420 [ 30.052324] ? lock_release+0xa40/0xa40 [ 30.056263] ? do_gettimeofday+0x190/0x190 [ 30.060466] ? lock_release+0xa40/0xa40 [ 30.064405] __netif_receive_skb+0x2c/0x1b0 [ 30.068693] ? __netif_receive_skb+0x2c/0x1b0 [ 30.073155] netif_receive_skb_internal+0x10b/0x670 [ 30.078137] ? dev_cpu_dead+0xb00/0xb00 [ 30.082078] ? net_rx_action+0x1910/0x1910 [ 30.086278] ? eth_type_trans+0x2b2/0x710 [ 30.090392] ? eth_gro_receive+0x820/0x820 [ 30.094594] napi_gro_frags+0x58a/0xaf0 [ 30.098533] ? napi_gro_receive+0x500/0x500 [ 30.102821] ? tun_get_user+0x2737/0x3940 [ 30.106933] tun_get_user+0x2760/0x3940 [ 30.110872] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 30.116026] ? is_bpf_text_address+0xa4/0x120 [ 30.120490] ? tun_build_skb.isra.50+0x1850/0x1850 [ 30.125385] ? find_held_lock+0x35/0x1d0 [ 30.129416] ? xt_table_unlock+0x52/0x60 [ 30.133448] ? mmdrop+0x18/0x30 [ 30.136698] ? drop_futex_key_refs.isra.13+0x63/0xa0 [ 30.141767] ? find_held_lock+0x35/0x1d0 [ 30.145805] ? tun_get+0x1ab/0x2e0 [ 30.149313] ? lock_release+0xa40/0xa40 [ 30.153252] ? __lock_is_held+0xb6/0x140 [ 30.157280] ? tun_get+0x1d4/0x2e0 [ 30.160786] ? tun_do_read+0x26c0/0x26c0 [ 30.164812] ? __check_object_size+0x8b/0x530 [ 30.169278] ? rcu_note_context_switch+0x710/0x710 [ 30.174176] tun_chr_write_iter+0xbd/0x1c0 [ 30.178379] do_iter_readv_writev+0x55c/0x830 [ 30.182840] ? vfs_dedupe_file_range+0x8f0/0x8f0 [ 30.187561] ? rw_verify_area+0xe5/0x2b0 [ 30.191588] do_iter_write+0x154/0x540 [ 30.195444] ? dup_iter+0x260/0x260 [ 30.199038] ? do_ip6t_set_ctl+0x104/0x5f0 [ 30.203240] vfs_writev+0x18a/0x340 [ 30.206846] ? vfs_iter_write+0xb0/0xb0 [ 30.210792] ? nf_setsockopt+0x93/0xc0 [ 30.214652] ? __fdget_pos+0x130/0x190 [ 30.218506] ? __fdget_raw+0x20/0x20 [ 30.222188] do_writev+0xfc/0x2a0 [ 30.225607] ? do_writev+0xfc/0x2a0 [ 30.229202] ? vfs_writev+0x340/0x340 [ 30.232972] ? mm_fault_error+0x2c0/0x2c0 [ 30.237089] ? move_addr_to_kernel+0x60/0x60 [ 30.241468] SyS_writev+0x27/0x30 [ 30.244890] ? SyS_readv+0x30/0x30 [ 30.248399] do_syscall_64+0x282/0x940 [ 30.252252] ? __do_page_fault+0xc90/0xc90 [ 30.256454] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.261177] ? syscall_return_slowpath+0x550/0x550 [ 30.266073] ? syscall_return_slowpath+0x2ac/0x550 [ 30.270968] ? prepare_exit_to_usermode+0x350/0x350 [ 30.275954] ? entry_SYSCALL_64_after_hwframe+0x36/0x9b [ 30.281288] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.286099] entry_SYSCALL_64_after_hwframe+0x26/0x9b [ 30.291256] RIP: 0033:0x453c60 [ 30.294413] RSP: 002b:00007fff48a9dba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 [ 30.302089] RAX: ffffffffffffffda RBX: 0000000000000066 RCX: 0000000000453c60 [ 30.3