[....] Starting enhanced syslogd: rsyslogd[ 12.306366] audit: type=1400 audit(1516401381.650:5): avc: denied { syslog } for pid=3506 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: [ 19.390239] audit: type=1400 audit(1516401388.734:6): avc: denied { map } for pid=3646 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 '10.128.15.216' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 32.439529] audit: type=1400 audit(1516401401.783:7): avc: denied { map } for pid=3662 comm="syzkaller242507" path="/root/syzkaller242507902" 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 [ 32.683564] ip (3729) used greatest stack depth: 16464 bytes left [ 32.714297] IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument executing program [ 33.043358] [ 33.044996] ============================================ [ 33.050418] WARNING: possible recursive locking detected [ 33.055839] 4.15.0-rc8+ #179 Not tainted [ 33.059874] -------------------------------------------- [ 33.065295] syzkaller242507/3662 is trying to acquire lock: [ 33.070970] (&vq->mutex){+.+.}, at: [<000000009c270901>] vhost_chr_write_iter+0x278/0x1580 [ 33.079434] [ 33.079434] but task is already holding lock: [ 33.085368] (&vq->mutex){+.+.}, at: [<000000009c270901>] vhost_chr_write_iter+0x278/0x1580 [ 33.093826] [ 33.093826] other info that might help us debug this: [ 33.100455] Possible unsafe locking scenario: [ 33.100455] [ 33.106478] CPU0 [ 33.109026] ---- [ 33.111575] lock(&vq->mutex); [ 33.114822] lock(&vq->mutex); [ 33.118067] [ 33.118067] *** DEADLOCK *** [ 33.118067] [ 33.124092] May be due to missing lock nesting notation [ 33.124092] [ 33.130987] 1 lock held by syzkaller242507/3662: [ 33.135795] #0: (&vq->mutex){+.+.}, at: [<000000009c270901>] vhost_chr_write_iter+0x278/0x1580 [ 33.145476] [ 33.145476] stack backtrace: [ 33.149940] CPU: 0 PID: 3662 Comm: syzkaller242507 Not tainted 4.15.0-rc8+ #179 [ 33.157353] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.166673] Call Trace: [ 33.169231] dump_stack+0x194/0x257 [ 33.172824] ? arch_local_irq_restore+0x53/0x53 [ 33.177478] __lock_acquire+0xe8f/0x3e00 [ 33.181510] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 33.186667] ? print_irqtrace_events+0x270/0x270 [ 33.191391] ? pagevec_lru_move_fn+0x178/0x230 [ 33.195940] ? lock_downgrade+0x980/0x980 [ 33.200058] ? print_irqtrace_events+0x270/0x270 [ 33.204782] ? lock_release+0xa40/0xa40 [ 33.208724] ? print_irqtrace_events+0x270/0x270 [ 33.213710] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 33.218781] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.223765] ? mark_held_locks+0xaf/0x100 [ 33.227880] ? get_kernel_page+0x110/0x110 [ 33.232083] ? check_noncircular+0x20/0x20 [ 33.236286] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.241271] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.245997] ? retint_kernel+0x10/0x10 [ 33.249856] lock_acquire+0x1d5/0x580 [ 33.253633] ? lock_acquire+0x1d5/0x580 [ 33.257579] ? vhost_chr_write_iter+0x278/0x1580 [ 33.262307] ? lru_cache_add+0x1c7/0x3a0 [ 33.266511] ? lock_release+0xa40/0xa40 [ 33.272371] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 33.278223] ? __mem_cgroup_threshold+0x8f0/0x8f0 [ 33.283036] ? rcu_note_context_switch+0x710/0x710 [ 33.287949] ? __might_sleep+0x95/0x190 [ 33.291894] ? vhost_chr_write_iter+0x278/0x1580 [ 33.296617] __mutex_lock+0x16f/0x1a80 [ 33.300473] ? vhost_chr_write_iter+0x278/0x1580 [ 33.305197] ? vhost_chr_write_iter+0x278/0x1580 [ 33.309923] ? check_noncircular+0x20/0x20 [ 33.314128] ? do_huge_pmd_anonymous_page+0xab4/0x1b00 [ 33.319376] ? mutex_lock_io_nested+0x1900/0x1900 [ 33.324198] ? pudp_huge_clear_flush+0x1f0/0x1f0 [ 33.328925] ? lock_release+0xa40/0xa40 [ 33.332870] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 33.338724] ? do_raw_spin_trylock+0x190/0x190 [ 33.343275] ? find_held_lock+0x35/0x1d0 [ 33.347306] ? __might_fault+0x110/0x1d0 [ 33.351336] ? lock_downgrade+0x980/0x980 [ 33.355452] ? lock_release+0xa40/0xa40 [ 33.359393] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 33.365255] ? __might_sleep+0x95/0x190 [ 33.369198] ? kasan_check_write+0x14/0x20 [ 33.373399] ? copyin+0x91/0xb0 [ 33.376732] ? _copy_from_iter+0x367/0xf30 [ 33.380934] ? depot_save_stack+0x3b5/0x490 [ 33.385223] ? lock_downgrade+0x980/0x980 [ 33.389339] ? lock_release+0xa40/0xa40 [ 33.393290] ? copy_page_to_iter+0xe10/0xe10 [ 33.397664] ? do_raw_spin_trylock+0x190/0x190 [ 33.402214] mutex_lock_nested+0x16/0x20 [ 33.406243] ? mutex_lock_nested+0x16/0x20 [ 33.410447] vhost_chr_write_iter+0x278/0x1580 [ 33.415000] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 33.420419] ? depot_save_stack+0x3b5/0x490 [ 33.424968] ? match_held_lock+0x3/0xa00 [ 33.429005] ? vhost_new_umem_range+0x740/0x740 [ 33.433644] ? __handle_mm_fault+0x80e/0x3ce0 [ 33.438119] ? find_held_lock+0x35/0x1d0 [ 33.442148] vhost_net_chr_write_iter+0x59/0x70 [ 33.447054] __vfs_write+0x684/0x970 [ 33.450738] ? kernel_read+0x120/0x120 [ 33.454594] ? _cond_resched+0x14/0x30 [ 33.458453] ? avc_policy_seqno+0x9/0x20 [ 33.462482] ? selinux_file_permission+0x82/0x460 [ 33.467295] ? rw_verify_area+0xe5/0x2b0 [ 33.471325] ? __fdget_raw+0x20/0x20 [ 33.475012] vfs_write+0x189/0x510 [ 33.478530] SyS_write+0xef/0x220 [ 33.481962] ? __do_page_fault+0x3d6/0xc90 [ 33.486599] ? SyS_read+0x220/0x220 [ 33.490197] ? do_fast_syscall_32+0x156/0xf9d [ 33.494664] ? SyS_read+0x220/0x220 [ 33.498260] do_fast_syscall_32+0x3ee/0xf9d [ 33.502989] ? do_int80_syscall_32+0x9d0/0x9d0 [ 33.508929] ? kasan_check_read+0x11/0x20 [ 33.513044] ? syscall_return_slowpath+0x550/0x550 [ 33.517942] ? SyS_rt_sigaction+0x94/0x1b0 [ 33.522147] ? SyS_sigprocmask+0x4b0/0x4b0 [ 33.526350] ? SyS_read+0x184/0x220 [ 33.529945] ? retint_user+0x18/0x18 [ 33.533630] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.538445] entry_SYSENTER_compat+0x54/0x63 [ 33.544043] RIP