[....] Starting enhanced syslogd: rsyslogd[ 17.843220] audit: type=1400 audit(1520235874.709:5): avc: denied { syslog } for pid=4109 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: [ 22.292480] audit: type=1400 audit(1520235879.159:6): avc: denied { map } for pid=4250 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 '10.128.0.11' (ECDSA) to the list of known hosts. [ 28.603112] audit: type=1400 audit(1520235885.469:7): avc: denied { map } for pid=4263 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 2018/03/05 07:44:45 parsed 1 programs 2018/03/05 07:44:45 executed programs: 0 [ 28.893126] audit: type=1400 audit(1520235885.759:8): avc: denied { map } for pid=4263 comm="syz-execprog" path="/root/syzkaller-shm722272623" 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 [ 28.902379] IPVS: ftp: loaded support on port[0] = 21 [ 28.951055] audit: type=1400 audit(1520235885.817:9): avc: denied { map } for pid=4272 comm="syz-executor0" path="/dev/ashmem" dev="devtmpfs" ino=9432 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 28.951366] [ 28.977275] ====================================================== [ 28.983565] WARNING: possible circular locking dependency detected [ 28.989854] 4.16.0-rc3+ #250 Not tainted [ 28.993884] ------------------------------------------------------ [ 29.000186] syz-executor0/4272 is trying to acquire lock: [ 29.005689] (&mm->mmap_sem){++++}, at: [<00000000791718ca>] __might_fault+0xe0/0x1d0 [ 29.013652] [ 29.013652] but task is already holding lock: [ 29.019594] (ashmem_mutex){+.+.}, at: [<00000000d8afa1ec>] ashmem_ioctl+0x3db/0x11b0 [ 29.027545] [ 29.027545] which lock already depends on the new lock. [ 29.027545] [ 29.035830] [ 29.035830] the existing dependency chain (in reverse order) is: [ 29.043434] [ 29.043434] -> #1 (ashmem_mutex){+.+.}: [ 29.048865] __mutex_lock+0x16f/0x1a80 [ 29.053246] mutex_lock_nested+0x16/0x20 [ 29.057798] ashmem_mmap+0x53/0x410 [ 29.061918] mmap_region+0xa99/0x15a0 [ 29.066211] do_mmap+0x6c0/0xe00 [ 29.070071] vm_mmap_pgoff+0x1de/0x280 [ 29.074456] SyS_mmap_pgoff+0x462/0x5f0 [ 29.079203] do_fast_syscall_32+0x3ec/0xf9f [ 29.084022] entry_SYSENTER_compat+0x70/0x7f [ 29.088923] [ 29.088923] -> #0 (&mm->mmap_sem){++++}: [ 29.094439] lock_acquire+0x1d5/0x580 [ 29.098730] __might_fault+0x13a/0x1d0 [ 29.103121] _copy_from_user+0x2c/0x110 [ 29.107585] ashmem_ioctl+0x438/0x11b0 [ 29.111963] compat_ashmem_ioctl+0x3e/0x50 [ 29.116693] compat_SyS_ioctl+0x151/0x2a30 [ 29.121420] do_fast_syscall_32+0x3ec/0xf9f [ 29.126246] entry_SYSENTER_compat+0x70/0x7f [ 29.131142] [ 29.131142] other info that might help us debug this: [ 29.131142] [ 29.139255] Possible unsafe locking scenario: [ 29.139255] [ 29.145292] CPU0 CPU1 [ 29.149932] ---- ---- [ 29.154567] lock(ashmem_mutex); [ 29.157990] lock(&mm->mmap_sem); [ 29.164018] lock(ashmem_mutex); [ 29.169983] lock(&mm->mmap_sem); [ 29.173492] [ 29.173492] *** DEADLOCK *** [ 29.173492] [ 29.179521] 1 lock held by syz-executor0/4272: [ 29.184070] #0: (ashmem_mutex){+.+.}, at: [<00000000d8afa1ec>] ashmem_ioctl+0x3db/0x11b0 [ 29.192451] [ 29.192451] stack backtrace: [ 29.196922] CPU: 1 PID: 4272 Comm: syz-executor0 Not tainted 4.16.0-rc3+ #250 [ 29.204167] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.213492] Call Trace: [ 29.216070] dump_stack+0x194/0x24d [ 29.219673] ? arch_local_irq_restore+0x53/0x53 [ 29.224317] print_circular_bug.isra.38+0x2cd/0x2dc [ 29.229389] ? save_trace+0xe0/0x2b0 [ 29.233073] __lock_acquire+0x30a8/0x3e00 [ 29.237963] ? ashmem_ioctl+0x3db/0x11b0 [ 29.242004] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.247167] ? __might_sleep+0x95/0x190 [ 29.251112] ? ashmem_ioctl+0x3db/0x11b0 [ 29.255146] ? __mutex_lock+0x16f/0x1a80 [ 29.259177] ? ashmem_ioctl+0x3db/0x11b0 [ 29.263210] ? ashmem_ioctl+0x3db/0x11b0 [ 29.267243] ? lock_downgrade+0x980/0x980 [ 29.271479] ? mutex_lock_io_nested+0x1900/0x1900 [ 29.276293] ? lock_release+0xa40/0xa40 [ 29.280240] ? do_futex+0x86f/0x22a0 [ 29.283926] ? vma_set_page_prot+0x16b/0x230 [ 29.288310] ? avc_ss_reset+0x110/0x110 [ 29.292347] lock_acquire+0x1d5/0x580 [ 29.296121] ? lock_acquire+0x1d5/0x580 [ 29.300082] ? __might_fault+0xe0/0x1d0 [ 29.304037] ? userfaultfd_unmap_complete+0x327/0x510 [ 29.309202] ? lock_release+0xa40/0xa40 [ 29.313149] ? check_same_owner+0x320/0x320 [ 29.317443] ? __might_sleep+0x95/0x190 [ 29.321390] __might_fault+0x13a/0x1d0 [ 29.325251] ? __might_fault+0xe0/0x1d0 [ 29.329221] _copy_from_user+0x2c/0x110 [ 29.333171] ashmem_ioctl+0x438/0x11b0 [ 29.337040] ? selinux_file_ioctl+0x444/0x690 [ 29.341510] ? __fget_light+0x2b2/0x3c0 [ 29.345458] ? ashmem_release+0x190/0x190 [ 29.349580] ? perf_trace_sched_switch+0x759/0xf60 [ 29.354485] ? compat_SyS_futex+0x288/0x380 [ 29.358779] compat_ashmem_ioctl+0x3e/0x50 [ 29.362986] compat_SyS_ioctl+0x151/0x2a30 [ 29.367194] ? do_fast_syscall_32+0x156/0xf9f [ 29.371660] ? ashmem_ioctl+0x11b0/0x11b0 [ 29.375780] ? do_ioctl+0x60/0x60 [ 29.379205] do_fast_syscall_32+0x3ec/0xf9f [ 29.383510] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.388078] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.392818] ? syscall_return_slowpath+0x2ac/0x550 [ 29.397729] ? prepare_exit_to_usermode+0x350/0x350 [ 29.402721] ? sysret32_from_system_call+0x5/0x3c [ 29.407536] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.412351] entry_SYSENTER_compat+0x70/0x7f [ 29.416731] RIP: 0023:0xf7f79c99 [ 29.420065] RSP: 002b:00000000ffc6bb1c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 29.427747] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000007709 [ 29.434988] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.442231] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 29.449474] R10: 0000000000000000 R11: 000