[....] Starting enhanced syslogd: rsyslogd[ 15.632648] audit: type=1400 audit(1520889632.536:5): avc: denied { syslog } for pid=3948 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: [ 17.994590] audit: type=1400 audit(1520889634.898:6): avc: denied { map } for pid=4086 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 '10.128.0.23' (ECDSA) to the list of known hosts. [ 24.270552] audit: type=1400 audit(1520889641.174:7): avc: denied { map } for pid=4100 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 2018/03/12 21:20:41 parsed 1 programs 2018/03/12 21:20:41 executed programs: 0 [ 24.524195] audit: type=1400 audit(1520889641.427:8): avc: denied { map } for pid=4100 comm="syz-execprog" path="/root/syzkaller-shm929737915" 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 [ 24.537254] IPVS: ftp: loaded support on port[0] = 21 [ 24.580686] audit: type=1400 audit(1520889641.484:9): avc: denied { map } for pid=4108 comm="syz-executor0" path="/dev/ashmem" dev="devtmpfs" ino=9479 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 24.581090] [ 24.606867] ====================================================== [ 24.613150] WARNING: possible circular locking dependency detected [ 24.619436] 4.16.0-rc5+ #261 Not tainted [ 24.623460] ------------------------------------------------------ [ 24.629741] syz-executor0/4108 is trying to acquire lock: [ 24.635241] (&mm->mmap_sem){++++}, at: [<00000000d3a93aec>] __might_fault+0xe0/0x1d0 [ 24.643188] [ 24.643188] but task is already holding lock: [ 24.649127] (ashmem_mutex){+.+.}, at: [<000000007fe580f6>] ashmem_ioctl+0x3db/0x11b0 [ 24.657081] [ 24.657081] which lock already depends on the new lock. [ 24.657081] [ 24.665362] [ 24.665362] the existing dependency chain (in reverse order) is: [ 24.672949] [ 24.672949] -> #1 (ashmem_mutex){+.+.}: [ 24.678378] __mutex_lock+0x16f/0x1a80 [ 24.682755] mutex_lock_nested+0x16/0x20 [ 24.687306] ashmem_mmap+0x53/0x410 [ 24.691425] mmap_region+0xa99/0x15a0 [ 24.695715] do_mmap+0x6c0/0xe00 [ 24.699580] vm_mmap_pgoff+0x1de/0x280 [ 24.703954] SyS_mmap_pgoff+0x462/0x5f0 [ 24.708418] do_fast_syscall_32+0x3ec/0xf9f [ 24.713230] entry_SYSENTER_compat+0x70/0x7f [ 24.718126] [ 24.718126] -> #0 (&mm->mmap_sem){++++}: [ 24.723644] lock_acquire+0x1d5/0x580 [ 24.727935] __might_fault+0x13a/0x1d0 [ 24.732314] _copy_from_user+0x2c/0x110 [ 24.736789] ashmem_ioctl+0x438/0x11b0 [ 24.741166] compat_ashmem_ioctl+0x3e/0x50 [ 24.745893] compat_SyS_ioctl+0x151/0x2a30 [ 24.750625] do_fast_syscall_32+0x3ec/0xf9f [ 24.755437] entry_SYSENTER_compat+0x70/0x7f [ 24.760337] [ 24.760337] other info that might help us debug this: [ 24.760337] [ 24.768452] Possible unsafe locking scenario: [ 24.768452] [ 24.774475] CPU0 CPU1 [ 24.779109] ---- ---- [ 24.783743] lock(ashmem_mutex); [ 24.787172] lock(&mm->mmap_sem); [ 24.793198] lock(ashmem_mutex); [ 24.799136] lock(&mm->mmap_sem); [ 24.802643] [ 24.802643] *** DEADLOCK *** [ 24.802643] [ 24.808671] 1 lock held by syz-executor0/4108: [ 24.813216] #0: (ashmem_mutex){+.+.}, at: [<000000007fe580f6>] ashmem_ioctl+0x3db/0x11b0 [ 24.821597] [ 24.821597] stack backtrace: [ 24.826064] CPU: 0 PID: 4108 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #261 [ 24.833304] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.842625] Call Trace: [ 24.845182] dump_stack+0x194/0x24d [ 24.848865] ? arch_local_irq_restore+0x53/0x53 [ 24.853505] print_circular_bug.isra.38+0x2cd/0x2dc [ 24.858489] ? save_trace+0xe0/0x2b0 [ 24.862179] __lock_acquire+0x30a8/0x3e00 [ 24.866300] ? ashmem_ioctl+0x3db/0x11b0 [ 24.870334] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 24.875493] ? __might_sleep+0x95/0x190 [ 24.879436] ? ashmem_ioctl+0x3db/0x11b0 [ 24.883465] ? __mutex_lock+0x16f/0x1a80 [ 24.887494] ? ashmem_ioctl+0x3db/0x11b0 [ 24.891526] ? ashmem_ioctl+0x3db/0x11b0 [ 24.895559] ? lock_downgrade+0x980/0x980 [ 24.899688] ? mutex_lock_io_nested+0x1900/0x1900 [ 24.904498] ? lock_release+0xa40/0xa40 [ 24.908449] ? do_futex+0x86f/0x22a0 [ 24.912138] ? vma_set_page_prot+0x16b/0x230 [ 24.916521] ? avc_ss_reset+0x110/0x110 [ 24.920470] lock_acquire+0x1d5/0x580 [ 24.924245] ? lock_acquire+0x1d5/0x580 [ 24.928190] ? __might_fault+0xe0/0x1d0 [ 24.932140] ? userfaultfd_unmap_complete+0x327/0x510 [ 24.937302] ? lock_release+0xa40/0xa40 [ 24.941253] ? check_same_owner+0x320/0x320 [ 24.945546] ? __might_sleep+0x95/0x190 [ 24.949503] __might_fault+0x13a/0x1d0 [ 24.953360] ? __might_fault+0xe0/0x1d0 [ 24.957307] _copy_from_user+0x2c/0x110 [ 24.961253] ashmem_ioctl+0x438/0x11b0 [ 24.965113] ? selinux_file_ioctl+0x444/0x690 [ 24.969579] ? __fget_light+0x2b2/0x3c0 [ 24.973523] ? ashmem_release+0x190/0x190 [ 24.977640] ? ttwu_stat+0x1c9/0x620 [ 24.981327] ? compat_SyS_futex+0x288/0x380 [ 24.985620] compat_ashmem_ioctl+0x3e/0x50 [ 24.989829] compat_SyS_ioctl+0x151/0x2a30 [ 24.994038] ? do_fast_syscall_32+0x156/0xf9f [ 24.998502] ? ashmem_ioctl+0x11b0/0x11b0 [ 25.002625] ? do_ioctl+0x60/0x60 [ 25.006060] do_fast_syscall_32+0x3ec/0xf9f [ 25.010356] ? do_int80_syscall_32+0x9c0/0x9c0 [ 25.014910] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.019639] ? syscall_return_slowpath+0x2ac/0x550 [ 25.024541] ? prepare_exit_to_usermode+0x350/0x350 [ 25.029530] ? sysret32_from_system_call+0x5/0x3c [ 25.034342] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.039156] entry_SYSENTER_compat+0x70/0x7f [ 25.043532] RIP: 0023:0xf7fe5c99 [ 25.046864] RSP: 002b:00000000ffd2c27c EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 25.054542] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000007709 [ 25.061785] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 25.069027] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 25.076270] R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000