[....] Starting enhanced syslogd: rsyslogd[ 17.055606] audit: type=1400 audit(1520076729.339:5): avc: denied { syslog } for pid=4102 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: [ 22.516248] audit: type=1400 audit(1520076734.799:6): avc: denied { map } for pid=4242 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 '10.128.10.8' (ECDSA) to the list of known hosts. [ 28.867739] audit: type=1400 audit(1520076741.151:7): avc: denied { map } for pid=4256 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 2018/03/03 11:32:21 parsed 1 programs 2018/03/03 11:32:21 executed programs: 0 [ 29.099347] audit: type=1400 audit(1520076741.382:8): avc: denied { map } for pid=4256 comm="syz-execprog" path="/root/syzkaller-shm658273399" 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 [ 29.109402] IPVS: ftp: loaded support on port[0] = 21 [ 29.155785] audit: type=1400 audit(1520076741.439:9): avc: denied { map } for pid=4265 comm="syz-executor0" path="/dev/ashmem" dev="devtmpfs" ino=9499 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 29.156057] [ 29.181952] ====================================================== [ 29.188676] WARNING: possible circular locking dependency detected [ 29.194965] 4.16.0-rc3+ #247 Not tainted [ 29.198993] ------------------------------------------------------ [ 29.205282] syz-executor0/4265 is trying to acquire lock: [ 29.210784] (&mm->mmap_sem){++++}, at: [<0000000006fbaffc>] __might_fault+0xe0/0x1d0 [ 29.218737] [ 29.218737] but task is already holding lock: [ 29.224678] (ashmem_mutex){+.+.}, at: [<0000000010fc4b31>] ashmem_ioctl+0x3db/0x11b0 [ 29.232622] [ 29.232622] which lock already depends on the new lock. [ 29.232622] [ 29.240901] [ 29.240901] the existing dependency chain (in reverse order) is: [ 29.248486] [ 29.248486] -> #1 (ashmem_mutex){+.+.}: [ 29.253914] __mutex_lock+0x16f/0x1a80 [ 29.258288] mutex_lock_nested+0x16/0x20 [ 29.262836] ashmem_mmap+0x53/0x410 [ 29.266954] mmap_region+0xa99/0x15a0 [ 29.271242] do_mmap+0x6c0/0xe00 [ 29.275100] vm_mmap_pgoff+0x1de/0x280 [ 29.279474] SyS_mmap_pgoff+0x462/0x5f0 [ 29.283939] do_fast_syscall_32+0x3ec/0xf9f [ 29.288752] entry_SYSENTER_compat+0x70/0x7f [ 29.293649] [ 29.293649] -> #0 (&mm->mmap_sem){++++}: [ 29.299165] lock_acquire+0x1d5/0x580 [ 29.303454] __might_fault+0x13a/0x1d0 [ 29.307831] _copy_from_user+0x2c/0x110 [ 29.312296] ashmem_ioctl+0x438/0x11b0 [ 29.316668] compat_ashmem_ioctl+0x3e/0x50 [ 29.321393] compat_SyS_ioctl+0x151/0x2a30 [ 29.326134] do_fast_syscall_32+0x3ec/0xf9f [ 29.330972] entry_SYSENTER_compat+0x70/0x7f [ 29.335866] [ 29.335866] other info that might help us debug this: [ 29.335866] [ 29.343973] Possible unsafe locking scenario: [ 29.343973] [ 29.349996] CPU0 CPU1 [ 29.354628] ---- ---- [ 29.359259] lock(ashmem_mutex); [ 29.362683] lock(&mm->mmap_sem); [ 29.368706] lock(ashmem_mutex); [ 29.374643] lock(&mm->mmap_sem); [ 29.378151] [ 29.378151] *** DEADLOCK *** [ 29.378151] [ 29.384177] 1 lock held by syz-executor0/4265: [ 29.388723] #0: (ashmem_mutex){+.+.}, at: [<0000000010fc4b31>] ashmem_ioctl+0x3db/0x11b0 [ 29.397109] [ 29.397109] stack backtrace: [ 29.401577] CPU: 1 PID: 4265 Comm: syz-executor0 Not tainted 4.16.0-rc3+ #247 [ 29.408817] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.418140] Call Trace: [ 29.420709] dump_stack+0x194/0x24d [ 29.424307] ? arch_local_irq_restore+0x53/0x53 [ 29.428952] print_circular_bug.isra.38+0x2cd/0x2dc [ 29.433940] ? save_trace+0xe0/0x2b0 [ 29.437625] __lock_acquire+0x30a8/0x3e00 [ 29.441744] ? ashmem_ioctl+0x3db/0x11b0 [ 29.445790] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 29.450956] ? __might_sleep+0x95/0x190 [ 29.454902] ? ashmem_ioctl+0x3db/0x11b0 [ 29.458935] ? __mutex_lock+0x16f/0x1a80 [ 29.462963] ? ashmem_ioctl+0x3db/0x11b0 [ 29.466995] ? ashmem_ioctl+0x3db/0x11b0 [ 29.471029] ? lock_downgrade+0x980/0x980 [ 29.475151] ? mutex_lock_io_nested+0x1900/0x1900 [ 29.479979] ? lock_release+0xa40/0xa40 [ 29.483927] ? do_futex+0x86f/0x22a0 [ 29.487616] ? vma_set_page_prot+0x16b/0x230 [ 29.491999] ? avc_ss_reset+0x110/0x110 [ 29.495946] lock_acquire+0x1d5/0x580 [ 29.499716] ? lock_acquire+0x1d5/0x580 [ 29.503662] ? __might_fault+0xe0/0x1d0 [ 29.507607] ? userfaultfd_unmap_complete+0x327/0x510 [ 29.512769] ? lock_release+0xa40/0xa40 [ 29.516712] ? check_same_owner+0x320/0x320 [ 29.521003] ? __might_sleep+0x95/0x190 [ 29.524947] __might_fault+0x13a/0x1d0 [ 29.528805] ? __might_fault+0xe0/0x1d0 [ 29.532750] _copy_from_user+0x2c/0x110 [ 29.536696] ashmem_ioctl+0x438/0x11b0 [ 29.540552] ? selinux_file_ioctl+0x444/0x690 [ 29.545018] ? __fget_light+0x2b2/0x3c0 [ 29.548973] ? ashmem_release+0x190/0x190 [ 29.553091] ? perf_trace_sched_process_exec+0x109/0x9f0 [ 29.558517] ? compat_SyS_futex+0x288/0x380 [ 29.562812] compat_ashmem_ioctl+0x3e/0x50 [ 29.567018] compat_SyS_ioctl+0x151/0x2a30 [ 29.571224] ? do_fast_syscall_32+0x156/0xf9f [ 29.575689] ? ashmem_ioctl+0x11b0/0x11b0 [ 29.579804] ? do_ioctl+0x60/0x60 [ 29.583228] do_fast_syscall_32+0x3ec/0xf9f [ 29.587520] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.592072] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.596798] ? syscall_return_slowpath+0x2ac/0x550 [ 29.601697] ? prepare_exit_to_usermode+0x350/0x350 [ 29.606690] ? sysret32_from_system_call+0x5/0x3c [ 29.611514] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.616326] entry_SYSENTER_compat+0x70/0x7f [ 29.620853] RIP: 0023:0xf7fd6c99 [ 29.624188] RSP: 002b:00000000ff86968c EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 29.631869] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000007709 [ 29.639108] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.646348] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 29.653590] R10: 0000000000000000 R11: 000000000000