[....] Starting enhanced syslogd: rsyslogd[ 14.548386] audit: type=1400 audit(1519077280.806:5): avc: denied { syslog } for pid=3908 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: [ 18.461207] audit: type=1400 audit(1519077284.719:6): avc: denied { map } for pid=4047 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 '10.128.15.213' (ECDSA) to the list of known hosts. [ 27.197373] audit: type=1400 audit(1519077293.455:7): avc: denied { map } for pid=4062 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 2018/02/19 21:54:53 parsed 1 programs 2018/02/19 21:54:53 executed programs: 0 [ 27.442671] audit: type=1400 audit(1519077293.700:8): avc: denied { map } for pid=4062 comm="syz-execprog" path="/root/syzkaller-shm083669173" 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 [ 27.453146] IPVS: ftp: loaded support on port[0] = 21 [ 27.682970] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready [ 28.010727] [ 28.012371] ===================================== [ 28.017180] WARNING: bad unlock balance detected! [ 28.021992] 4.16.0-rc1+ #232 Not tainted [ 28.026018] ------------------------------------- [ 28.030829] syz-executor0/4197 is trying to release lock (rcu_read_lock_bh) at: [ 28.038255] [] hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 28.045236] but there are no more locks to release! [ 28.050217] [ 28.050217] other info that might help us debug this: [ 28.056851] 3 locks held by syz-executor0/4197: [ 28.061484] #0: (&tfile->napi_mutex){+.+.}, at: [<0000000042dd1e08>] tun_get_user+0xe6c/0x3940 [ 28.070396] #1: (rcu_read_lock){....}, at: [<000000004a407b1c>] netif_receive_skb_internal+0xa2/0x670 [ 28.079905] #2: (rcu_read_lock){....}, at: [<00000000c7862fa2>] ipv6_rcv+0x1446/0x1fa0 [ 28.088115] [ 28.088115] stack backtrace: [ 28.092582] CPU: 1 PID: 4197 Comm: syz-executor0 Not tainted 4.16.0-rc1+ #232 [ 28.099822] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.109154] Call Trace: [ 28.111715] dump_stack+0x194/0x257 [ 28.115321] ? arch_local_irq_restore+0x53/0x53 [ 28.119975] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 28.125398] print_unlock_imbalance_bug+0x12f/0x140 [ 28.130385] lock_release+0x6fe/0xa40 [ 28.134157] ? hashlimit_mt_common.isra.10+0x1beb/0x2610 [ 28.139580] ? lock_downgrade+0x980/0x980 [ 28.143696] ? lock_release+0xa40/0xa40 [ 28.147637] ? __raw_spin_lock_init+0x1c/0x100 [ 28.152205] ? do_raw_spin_trylock+0x190/0x190 [ 28.156762] hashlimit_mt_common.isra.10+0x1c08/0x2610 [ 28.162010] ? dsthash_find+0x5b0/0x5b0 [ 28.165956] ? __lock_acquire+0x664/0x3e00 [ 28.170174] ? get_page_from_freelist+0x2d7f/0x52d0 [ 28.175162] ? get_page_from_freelist+0x2deb/0x52d0 [ 28.180152] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.185312] ? lock_release+0xa40/0xa40 [ 28.189254] ? __bfs+0xaa/0x750 [ 28.192507] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 28.197245] ? lock_downgrade+0x980/0x980 [ 28.201364] hashlimit_mt+0x78/0x90 [ 28.204962] ? hashlimit_mt+0x78/0x90 [ 28.208735] ip6t_do_table+0x98d/0x1a30 [ 28.212679] ? is_bpf_text_address+0x7b/0x120 [ 28.217150] ? lock_downgrade+0x980/0x980 [ 28.221267] ? __bfs+0xaa/0x750 [ 28.224524] ? check_noncircular+0x20/0x20 [ 28.228729] ? ip6t_error+0x60/0x60 [ 28.232324] ? find_held_lock+0x35/0x1d0 [ 28.236354] ? check_noncircular+0x20/0x20 [ 28.240566] ? lock_acquire+0x1d5/0x580 [ 28.244509] ? lock_acquire+0x1d5/0x580 [ 28.248457] ? ipv6_rcv+0x1446/0x1fa0 [ 28.252228] ? lock_release+0xa40/0xa40 [ 28.256174] ip6table_raw_hook+0x65/0x80 [ 28.260204] nf_hook_slow+0xba/0x1a0 [ 28.263886] ipv6_rcv+0x1687/0x1fa0 [ 28.267485] ? ip6_rcv_finish+0x8c0/0x8c0 [ 28.271608] ? __lock_acquire+0x664/0x3e00 [ 28.275824] ? ip6_input+0x560/0x560 [ 28.279510] ? ip6_rcv_finish+0x8c0/0x8c0 [ 28.283631] __netif_receive_skb_core+0x1a41/0x3460 [ 28.288615] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.293777] ? nf_ingress+0x9f0/0x9f0 [ 28.297551] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.302712] ? do_csum+0x288/0x360 [ 28.306227] ? csum_partial+0x21/0x30 [ 28.309998] ? csum_partial_ext+0x25/0x30 [ 28.314117] ? check_noncircular+0x20/0x20 [ 28.318319] ? __skb_checksum+0x4a9/0x7e0 [ 28.322437] ? find_held_lock+0x35/0x1d0 [ 28.326468] ? print_irqtrace_events+0x270/0x270 [ 28.331193] ? lock_downgrade+0x980/0x980 [ 28.335314] ? pvclock_read_flags+0x160/0x160 [ 28.339788] ? mark_held_locks+0xaf/0x100 [ 28.343907] ? lock_acquire+0x1d5/0x580 [ 28.347850] ? lock_acquire+0x1d5/0x580 [ 28.351794] ? netif_receive_skb_internal+0xa2/0x670 [ 28.356876] ? ktime_get_with_offset+0x2c1/0x420 [ 28.361604] ? lock_release+0xa40/0xa40 [ 28.365557] ? do_gettimeofday+0x190/0x190 [ 28.369764] ? lock_release+0xa40/0xa40 [ 28.373708] __netif_receive_skb+0x2c/0x1b0 [ 28.378001] ? __netif_receive_skb+0x2c/0x1b0 [ 28.382478] netif_receive_skb_internal+0x10b/0x670 [ 28.387464] ? dev_cpu_dead+0xb00/0xb00 [ 28.391408] ? net_rx_action+0x1910/0x1910 [ 28.395611] ? eth_type_trans+0x2b2/0x710 [ 28.399728] ? eth_gro_receive+0x820/0x820 [ 28.403930] napi_gro_frags+0x58a/0xaf0 [ 28.407872] ? napi_gro_receive+0x500/0x500 [ 28.412167] ? tun_get_user+0x2737/0x3940 [ 28.416282] tun_get_user+0x2760/0x3940 [ 28.420229] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.425390] ? do_huge_pmd_anonymous_page+0xab1/0x1b00 [ 28.430638] ? tun_build_skb.isra.50+0x1850/0x1850 [ 28.435538] ? clear_huge_page+0x309/0x730 [ 28.439746] ? _raw_spin_unlock+0x22/0x30 [ 28.443863] ? mmdrop+0x18/0x30 [ 28.447123] ? drop_futex_key_refs.isra.13+0x63/0xa0 [ 28.452195] ? find_held_lock+0x35/0x1d0 [ 28.456230] ? tun_get+0x1ab/0x2e0 [ 28.459740] ? lock_release+0xa40/0xa40 [ 28.463684] ? __lock_is_held+0xb6/0x140 [ 28.467717] ? tun_get+0x1d4/0x2e0 [ 28.471226] ? tun_do_read+0x26c0/0x26c0 [ 28.475257] ? __check_object_size+0x8b/0x530 [ 28.479722] ? rcu_note_context_switch+0x710/0x710 [ 28.484620] tun_chr_write_iter+0xbd/0x1c0 [ 28.488822] do_iter_readv_writev+0x55c/0x830 [ 28.493290] ? vfs_dedupe_file_range+0x8f0/0x8f0 [ 28.498015] ? rw_verify_area+0xe5/0x2b0 [ 28.502045] do_iter_write+0x154/0x540 [ 28.505912] ? dup_iter+0x260/0x260 [ 28.509515] vfs_writev+0x18a/0x340 [ 28.513115] ? vfs_iter_write+0xb0/0xb0 [ 28.517064] ? __fdget_pos+0x130/0x190 [ 28.520920] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 28.525470] ? __fdget_raw+0x20/0x20 [ 28.529151] do_writev+0xfc/0x2a0 [ 28.532571] ? do_writev+0xfc/0x2a0 [ 28.536167] ? vfs_writev+0x340/0x340 [ 28.539941] ? mm_fault_error+0x2c0/0x2c0 [ 28.544061] ? move_addr_to_kernel+0x60/0x60 [ 28.548439] SyS_writev+0x27/0x30 [ 28.551860] ? SyS_readv+0x30/0x30 [ 28.555368] do_syscall_64+0x282/0x940 [ 28.559221] ? __do_page_fault+0xc90/0xc90 [ 28.563425] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 28.568149] ? syscall_return_slowpath+0x550/0x550 [ 28.573054] ? syscall_return_slowpath+0x2ac/0x550 [ 28.577953] ? prepare_exit_to_usermode+0x350/0x350 [ 28.582939] ? entry_SYSCALL_64_after_hwframe+0x36/0x9b [ 28.588271] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.593086] entry_SYSCALL_64_after_hwframe+0x26/0x9b [ 28.598244] RIP: 0033:0x453c60 [ 28.601404] RSP: 002b:00007ffda8d41a78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 [ 28.609081] RAX: ffffffffffffffda RBX: 00000000000