[....] Starting enhanced syslogd: rsyslogd[ 17.345458] audit: type=1400 audit(1520340178.780:5): avc: denied { syslog } for pid=4093 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: [ 22.422491] audit: type=1400 audit(1520340183.857:6): avc: denied { map } for pid=4233 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 '10.128.0.40' (ECDSA) to the list of known hosts. [ 28.730809] audit: type=1400 audit(1520340190.165:7): avc: denied { map } for pid=4247 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 2018/03/06 12:43:10 parsed 1 programs 2018/03/06 12:43:10 executed programs: 0 [ 28.974948] audit: type=1400 audit(1520340190.409:8): avc: denied { map } for pid=4247 comm="syz-execprog" path="/root/syzkaller-shm264364554" 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 [ 28.991143] IPVS: ftp: loaded support on port[0] = 21 [ 29.031314] audit: type=1400 audit(1520340190.466:9): avc: denied { map } for pid=4256 comm="syz-executor0" path="/dev/ashmem" dev="devtmpfs" ino=123 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 29.031634] [ 29.057405] ====================================================== [ 29.064192] WARNING: possible circular locking dependency detected [ 29.070477] 4.16.0-rc4+ #252 Not tainted [ 29.074505] ------------------------------------------------------ [ 29.080790] syz-executor0/4256 is trying to acquire lock: [ 29.086294] (&mm->mmap_sem){++++}, at: [<000000000e8c4468>] __might_fault+0xe0/0x1d0 [ 29.094251] [ 29.094251] but task is already holding lock: [ 29.100186] (ashmem_mutex){+.+.}, at: [<0000000078c75599>] ashmem_ioctl+0x3db/0x11b0 [ 29.108127] [ 29.108127] which lock already depends on the new lock. [ 29.108127] [ 29.116407] [ 29.116407] the existing dependency chain (in reverse order) is: [ 29.123992] [ 29.123992] -> #1 (ashmem_mutex){+.+.}: [ 29.129421] __mutex_lock+0x16f/0x1a80 [ 29.133799] mutex_lock_nested+0x16/0x20 [ 29.138352] ashmem_mmap+0x53/0x410 [ 29.142469] mmap_region+0xa99/0x15a0 [ 29.146756] do_mmap+0x6c0/0xe00 [ 29.150613] vm_mmap_pgoff+0x1de/0x280 [ 29.154988] SyS_mmap_pgoff+0x462/0x5f0 [ 29.159454] do_fast_syscall_32+0x3ec/0xf9f [ 29.164266] entry_SYSENTER_compat+0x70/0x7f [ 29.169166] [ 29.169166] -> #0 (&mm->mmap_sem){++++}: [ 29.174676] lock_acquire+0x1d5/0x580 [ 29.178981] __might_fault+0x13a/0x1d0 [ 29.183357] _copy_from_user+0x2c/0x110 [ 29.187820] ashmem_ioctl+0x438/0x11b0 [ 29.192218] compat_ashmem_ioctl+0x3e/0x50 [ 29.196943] compat_SyS_ioctl+0x151/0x2a30 [ 29.201668] do_fast_syscall_32+0x3ec/0xf9f [ 29.206479] entry_SYSENTER_compat+0x70/0x7f [ 29.211371] [ 29.211371] other info that might help us debug this: [ 29.211371] [ 29.219480] Possible unsafe locking scenario: [ 29.219480] [ 29.225502] CPU0 CPU1 [ 29.230138] ---- ---- [ 29.234773] lock(ashmem_mutex); [ 29.238194] lock(&mm->mmap_sem); [ 29.244222] lock(ashmem_mutex); [ 29.250159] lock(&mm->mmap_sem); [ 29.253665] [ 29.253665] *** DEADLOCK *** [ 29.253665] [ 29.259694] 1 lock held by syz-executor0/4256: [ 29.264243] #0: (ashmem_mutex){+.+.}, at: [<0000000078c75599>] ashmem_ioctl+0x3db/0x11b0 [ 29.272623] [ 29.272623] stack backtrace: [ 29.277087] CPU: 1 PID: 4256 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #252 [ 29.284327] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.293650] Call Trace: [ 29.296208] dump_stack+0x194/0x24d [ 29.299806] ? arch_local_irq_restore+0x53/0x53 [ 29.304446] print_circular_bug.isra.38+0x2cd/0x2dc [ 29.309428] ? save_trace+0xe0/0x2b0 [ 29.313114] __lock_acquire+0x30a8/0x3e00 [ 29.317235] ? ashmem_ioctl+0x3db/0x11b0 [ 29.321271] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.326515] ? __might_sleep+0x95/0x190 [ 29.330457] ? ashmem_ioctl+0x3db/0x11b0 [ 29.334488] ? __mutex_lock+0x16f/0x1a80 [ 29.338517] ? ashmem_ioctl+0x3db/0x11b0 [ 29.342546] ? ashmem_ioctl+0x3db/0x11b0 [ 29.346576] ? lock_downgrade+0x980/0x980 [ 29.350692] ? mutex_lock_io_nested+0x1900/0x1900 [ 29.355501] ? lock_release+0xa40/0xa40 [ 29.359449] ? do_futex+0x86f/0x22a0 [ 29.363138] ? vma_set_page_prot+0x16b/0x230 [ 29.367522] ? avc_ss_reset+0x110/0x110 [ 29.371466] lock_acquire+0x1d5/0x580 [ 29.375236] ? lock_acquire+0x1d5/0x580 [ 29.379179] ? __might_fault+0xe0/0x1d0 [ 29.383123] ? userfaultfd_unmap_complete+0x327/0x510 [ 29.388282] ? lock_release+0xa40/0xa40 [ 29.392225] ? check_same_owner+0x320/0x320 [ 29.396517] ? __might_sleep+0x95/0x190 [ 29.400462] __might_fault+0x13a/0x1d0 [ 29.404316] ? __might_fault+0xe0/0x1d0 [ 29.408261] _copy_from_user+0x2c/0x110 [ 29.412205] ashmem_ioctl+0x438/0x11b0 [ 29.416075] ? selinux_file_ioctl+0x444/0x690 [ 29.420543] ? __fget_light+0x2b2/0x3c0 [ 29.424489] ? ashmem_release+0x190/0x190 [ 29.428609] ? perf_trace_sched_switch+0x759/0xf60 [ 29.433508] ? compat_SyS_futex+0x288/0x380 [ 29.437799] compat_ashmem_ioctl+0x3e/0x50 [ 29.442006] compat_SyS_ioctl+0x151/0x2a30 [ 29.446211] ? do_fast_syscall_32+0x156/0xf9f [ 29.450675] ? ashmem_ioctl+0x11b0/0x11b0 [ 29.454795] ? do_ioctl+0x60/0x60 [ 29.458225] do_fast_syscall_32+0x3ec/0xf9f [ 29.462517] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.467071] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.471798] ? syscall_return_slowpath+0x2ac/0x550 [ 29.476698] ? prepare_exit_to_usermode+0x350/0x350 [ 29.481687] ? sysret32_from_system_call+0x5/0x3c [ 29.486499] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.491310] entry_SYSENTER_compat+0x70/0x7f [ 29.495689] RIP: 0023:0xf7f29c99 [ 29.499029] RSP: 002b:00000000ff9bdf9c EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 29.506713] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000007709 [ 29.513965] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.521204] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 29.528444] R10: 0000000000000000 R11: 0000000000000000 R12: