[....] Starting enhanced syslogd: rsyslogd[ 17.276769] audit: type=1400 audit(1519944598.484:5): avc: denied { syslog } for pid=4074 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.933804] audit: type=1400 audit(1519944603.141:6): avc: denied { map } for pid=4213 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 '10.128.0.14' (ECDSA) to the list of known hosts. [ 28.300427] audit: type=1400 audit(1519944609.508:7): avc: denied { map } for pid=4227 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 2018/03/01 22:50:09 parsed 1 programs 2018/03/01 22:50:09 executed programs: 0 [ 28.562305] audit: type=1400 audit(1519944609.770:8): avc: denied { map } for pid=4227 comm="syz-execprog" path="/root/syzkaller-shm903238524" 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 [ 28.599879] IPVS: ftp: loaded support on port[0] = 21 [ 28.631300] audit: type=1400 audit(1519944609.839:9): avc: denied { map } for pid=4237 comm="syz-executor0" path="/dev/ashmem" dev="devtmpfs" ino=1110 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 28.631663] [ 28.657498] ====================================================== [ 28.663788] WARNING: possible circular locking dependency detected [ 28.670077] 4.16.0-rc3+ #245 Not tainted [ 28.674107] ------------------------------------------------------ [ 28.680393] syz-executor0/4237 is trying to acquire lock: [ 28.685895] (&mm->mmap_sem){++++}, at: [<0000000088cea99c>] __might_fault+0xe0/0x1d0 [ 28.693844] [ 28.693844] but task is already holding lock: [ 28.699785] (ashmem_mutex){+.+.}, at: [<000000002fc4b556>] ashmem_ioctl+0x3db/0x11b0 [ 28.707735] [ 28.707735] which lock already depends on the new lock. [ 28.707735] [ 28.716025] [ 28.716025] the existing dependency chain (in reverse order) is: [ 28.723621] [ 28.723621] -> #1 (ashmem_mutex){+.+.}: [ 28.729056] __mutex_lock+0x16f/0x1a80 [ 28.733438] mutex_lock_nested+0x16/0x20 [ 28.737992] ashmem_mmap+0x53/0x410 [ 28.742110] mmap_region+0xa99/0x15a0 [ 28.746401] do_mmap+0x6c0/0xe00 [ 28.750262] vm_mmap_pgoff+0x1de/0x280 [ 28.754650] SyS_mmap_pgoff+0x462/0x5f0 [ 28.759122] do_fast_syscall_32+0x3ec/0xf9f [ 28.763938] entry_SYSENTER_compat+0x70/0x7f [ 28.768837] [ 28.768837] -> #0 (&mm->mmap_sem){++++}: [ 28.774360] lock_acquire+0x1d5/0x580 [ 28.778652] __might_fault+0x13a/0x1d0 [ 28.783033] _copy_from_user+0x2c/0x110 [ 28.787524] ashmem_ioctl+0x438/0x11b0 [ 28.791901] compat_ashmem_ioctl+0x3e/0x50 [ 28.796634] compat_SyS_ioctl+0x151/0x2a30 [ 28.801369] do_fast_syscall_32+0x3ec/0xf9f [ 28.806185] entry_SYSENTER_compat+0x70/0x7f [ 28.811082] [ 28.811082] other info that might help us debug this: [ 28.811082] [ 28.819195] Possible unsafe locking scenario: [ 28.819195] [ 28.825224] CPU0 CPU1 [ 28.829858] ---- ---- [ 28.834494] lock(ashmem_mutex); [ 28.837917] lock(&mm->mmap_sem); [ 28.843945] lock(ashmem_mutex); [ 28.849885] lock(&mm->mmap_sem); [ 28.853394] [ 28.853394] *** DEADLOCK *** [ 28.853394] [ 28.859825] 1 lock held by syz-executor0/4237: [ 28.864374] #0: (ashmem_mutex){+.+.}, at: [<000000002fc4b556>] ashmem_ioctl+0x3db/0x11b0 [ 28.872772] [ 28.872772] stack backtrace: [ 28.877245] CPU: 1 PID: 4237 Comm: syz-executor0 Not tainted 4.16.0-rc3+ #245 [ 28.884489] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.893827] Call Trace: [ 28.896393] dump_stack+0x194/0x24d [ 28.899992] ? arch_local_irq_restore+0x53/0x53 [ 28.904656] print_circular_bug.isra.38+0x2cd/0x2dc [ 28.909651] ? save_trace+0xe0/0x2b0 [ 28.913344] __lock_acquire+0x30a8/0x3e00 [ 28.917466] ? ashmem_ioctl+0x3db/0x11b0 [ 28.921504] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.926666] ? __might_sleep+0x95/0x190 [ 28.930613] ? ashmem_ioctl+0x3db/0x11b0 [ 28.934645] ? __mutex_lock+0x16f/0x1a80 [ 28.938676] ? ashmem_ioctl+0x3db/0x11b0 [ 28.942707] ? ashmem_ioctl+0x3db/0x11b0 [ 28.946743] ? lock_downgrade+0x980/0x980 [ 28.950863] ? mutex_lock_io_nested+0x1900/0x1900 [ 28.955679] ? lock_release+0xa40/0xa40 [ 28.959625] ? do_futex+0x86f/0x22a0 [ 28.963326] ? vma_set_page_prot+0x16b/0x230 [ 28.967722] ? avc_ss_reset+0x110/0x110 [ 28.971677] lock_acquire+0x1d5/0x580 [ 28.975449] ? lock_acquire+0x1d5/0x580 [ 28.979395] ? __might_fault+0xe0/0x1d0 [ 28.983344] ? userfaultfd_unmap_complete+0x327/0x510 [ 28.988505] ? lock_release+0xa40/0xa40 [ 28.992454] ? check_same_owner+0x320/0x320 [ 28.996751] ? __might_sleep+0x95/0x190 [ 29.000699] __might_fault+0x13a/0x1d0 [ 29.004557] ? __might_fault+0xe0/0x1d0 [ 29.008507] _copy_from_user+0x2c/0x110 [ 29.012458] ashmem_ioctl+0x438/0x11b0 [ 29.016321] ? selinux_file_ioctl+0x444/0x690 [ 29.020789] ? __fget_light+0x2b2/0x3c0 [ 29.024758] ? ashmem_release+0x190/0x190 [ 29.028880] ? perf_trace_sched_process_exec+0x109/0x9f0 [ 29.034308] ? compat_SyS_futex+0x288/0x380 [ 29.038605] compat_ashmem_ioctl+0x3e/0x50 [ 29.042818] compat_SyS_ioctl+0x151/0x2a30 [ 29.047035] ? do_fast_syscall_32+0x156/0xf9f [ 29.051507] ? ashmem_ioctl+0x11b0/0x11b0 [ 29.055629] ? do_ioctl+0x60/0x60 [ 29.059056] do_fast_syscall_32+0x3ec/0xf9f [ 29.063351] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.067917] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.072648] ? syscall_return_slowpath+0x2ac/0x550 [ 29.077550] ? prepare_exit_to_usermode+0x350/0x350 [ 29.082539] ? sysret32_from_system_call+0x5/0x3c [ 29.087357] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.092177] entry_SYSENTER_compat+0x70/0x7f [ 29.096566] RIP: 0023:0xf7f39c99 [ 29.099900] RSP: 002b:00000000ffa34cec EFLAGS: 00000286 ORIG_RAX: 0000000000000036 [ 29.107578] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000007709 [ 29.114820] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.122060] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 29.129301] R10: 0000000000000000 R11: 000000000