[....] Starting enhanced syslogd: rsyslogd[ 13.537124] audit: type=1400 audit(1516399542.298:5): avc: denied { syslog } for pid=3520 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 19.258384] audit: type=1400 audit(1516399548.020:6): avc: denied { map } for pid=3660 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 '10.128.0.15' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 25.491236] audit: type=1400 audit(1516399554.253:7): avc: denied { map } for pid=3674 comm="syzkaller936067" path="/root/syzkaller936067954" 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 [ 25.757522] 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 [ 26.070215] [ 26.071856] ============================================ [ 26.077443] WARNING: possible recursive locking detected [ 26.082859] 4.15.0-rc8+ #269 Not tainted [ 26.086886] -------------------------------------------- [ 26.092313] syzkaller936067/3674 is trying to acquire lock: [ 26.097987] (&vq->mutex){+.+.}, at: [<000000002a9560fc>] vhost_chr_write_iter+0x278/0x1580 [ 26.106453] [ 26.106453] but task is already holding lock: [ 26.112389] (&vq->mutex){+.+.}, at: [<000000002a9560fc>] vhost_chr_write_iter+0x278/0x1580 [ 26.120849] [ 26.120849] other info that might help us debug this: [ 26.127482] Possible unsafe locking scenario: [ 26.127482] [ 26.133504] CPU0 [ 26.136051] ---- [ 26.138602] lock(&vq->mutex); [ 26.141848] lock(&vq->mutex); [ 26.145092] [ 26.145092] *** DEADLOCK *** [ 26.145092] [ 26.151117] May be due to missing lock nesting notation [ 26.151117] [ 26.158011] 1 lock held by syzkaller936067/3674: [ 26.162730] #0: (&vq->mutex){+.+.}, at: [<000000002a9560fc>] vhost_chr_write_iter+0x278/0x1580 [ 26.171629] [ 26.171629] stack backtrace: [ 26.176092] CPU: 0 PID: 3674 Comm: syzkaller936067 Not tainted 4.15.0-rc8+ #269 [ 26.183512] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.192832] Call Trace: [ 26.195390] dump_stack+0x194/0x257 [ 26.198983] ? arch_local_irq_restore+0x53/0x53 [ 26.203624] __lock_acquire+0xe8f/0x3e00 [ 26.207655] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 26.212813] ? get_kernel_page+0x110/0x110 [ 26.217017] ? __lru_cache_add+0x2a4/0x410 [ 26.221230] ? save_stack+0xa3/0xd0 [ 26.224829] ? print_irqtrace_events+0x270/0x270 [ 26.229551] ? __handle_mm_fault+0x1a0c/0x3ce0 [ 26.234103] ? check_noncircular+0x20/0x20 [ 26.238305] ? get_mem_cgroup_from_mm+0x710/0x710 [ 26.243115] ? lru_cache_add_file+0x20/0x20 [ 26.247403] ? check_noncircular+0x20/0x20 [ 26.251604] ? __lock_acquire+0x664/0x3e00 [ 26.255804] ? mark_held_locks+0xaf/0x100 [ 26.259922] lock_acquire+0x1d5/0x580 [ 26.263689] ? lock_acquire+0x1d5/0x580 [ 26.267633] ? vhost_chr_write_iter+0x278/0x1580 [ 26.272360] ? lock_release+0xa40/0xa40 [ 26.276304] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 26.282157] ? do_raw_spin_trylock+0x190/0x190 [ 26.286708] ? rcu_note_context_switch+0x710/0x710 [ 26.291604] ? __might_sleep+0x95/0x190 [ 26.295545] ? vhost_chr_write_iter+0x278/0x1580 [ 26.300269] __mutex_lock+0x16f/0x1a80 [ 26.304121] ? vhost_chr_write_iter+0x278/0x1580 [ 26.308848] ? vhost_chr_write_iter+0x278/0x1580 [ 26.313571] ? __thp_get_unmapped_area+0x130/0x130 [ 26.318470] ? __lock_acquire+0x664/0x3e00 [ 26.322673] ? mutex_lock_io_nested+0x1900/0x1900 [ 26.329274] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 26.334788] ? find_held_lock+0x35/0x1d0 [ 26.338819] ? __might_fault+0x110/0x1d0 [ 26.342851] ? lock_downgrade+0x980/0x980 [ 26.346967] ? lock_release+0xa40/0xa40 [ 26.350910] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 26.356762] ? __might_sleep+0x95/0x190 [ 26.360705] ? kasan_check_write+0x14/0x20 [ 26.364907] ? copyin+0x91/0xb0 [ 26.368156] ? _copy_from_iter+0x367/0xf30 [ 26.372360] ? __handle_mm_fault+0x80e/0x3ce0 [ 26.376822] ? check_noncircular+0x20/0x20 [ 26.381026] ? copy_page_to_iter+0xe10/0xe10 [ 26.385404] mutex_lock_nested+0x16/0x20 [ 26.389433] ? mutex_lock_nested+0x16/0x20 [ 26.393639] vhost_chr_write_iter+0x278/0x1580 [ 26.398191] ? handle_mm_fault+0x248/0x8d0 [ 26.402397] ? find_held_lock+0x3/0x1d0 [ 26.406339] ? vhost_new_umem_range+0x740/0x740 [ 26.410979] ? __do_page_fault+0x5f7/0xc90 [ 26.415185] vhost_net_chr_write_iter+0x59/0x70 [ 26.419822] __vfs_write+0x684/0x970 [ 26.423516] ? kernel_read+0x120/0x120 [ 26.427376] ? _cond_resched+0x14/0x30 [ 26.431236] ? avc_policy_seqno+0x9/0x20 [ 26.435264] ? selinux_file_permission+0x82/0x460 [ 26.440075] ? rw_verify_area+0xe5/0x2b0 [ 26.444104] ? __fdget_raw+0x20/0x20 [ 26.447786] vfs_write+0x189/0x510 [ 26.451302] SyS_write+0xef/0x220 [ 26.454721] ? filp_open+0x70/0x70 [ 26.458231] ? SyS_read+0x220/0x220 [ 26.461826] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 26.466811] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.471537] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 26.476264] RIP: 0033:0x444d89 [ 26.479426] RSP: 002b:00007ffeee5fa4b8 EFLAGS: 00000207 ORIG_RAX: 0000000000000001 [ 26.487101] RAX: ffffffffffffffda RBX: 00000000004a6692 RCX: 0000000000444d89 [ 26.494338] RDX: 0000000000000068 RSI: 00000000209e6f98 RDI: 0000000000000004 [ 26.501574] RBP: 00007ffeee5fa568 R08: 0000000000000000 R09: 0000000000000000 [ 26.508810] R10: 0000000000000000 R11: 0000000000000207 R12: 00007ffeee5fa568 [ 26.516046] R13: 00000000004022b0 R14: 0000000000000000 R15: 0000000