[....] Starting enhanced syslogd: rsyslogd[ 16.582616] audit: type=1400 audit(1520496996.690:5): avc: denied { syslog } for pid=4079 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: [ 22.137142] audit: type=1400 audit(1520497002.244:6): avc: denied { map } for pid=4219 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 '10.128.10.0' (ECDSA) to the list of known hosts. executing program [ 28.459330] audit: type=1400 audit(1520497008.566:7): avc: denied { map } for pid=4233 comm="syzkaller411811" path="/root/syzkaller411811551" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 28.462715] [ 28.485278] audit: type=1400 audit(1520497008.567:8): avc: denied { map } for pid=4233 comm="syzkaller411811" path="/dev/ashmem" dev="devtmpfs" ino=9500 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 28.486835] ====================================================== [ 28.486837] WARNING: possible circular locking dependency detected [ 28.486842] 4.16.0-rc4+ #345 Not tainted [ 28.486843] ------------------------------------------------------ [ 28.486846] syzkaller411811/4233 is trying to acquire lock: [ 28.486848] (&mm->mmap_sem){++++}, at: [<00000000ff8e482a>] __might_fault+0xe0/0x1d0 [ 28.486871] [ 28.486871] but task is already holding lock: [ 28.553994] (ashmem_mutex){+.+.}, at: [<00000000f5df116b>] ashmem_ioctl+0x3db/0x11b0 [ 28.561947] [ 28.561947] which lock already depends on the new lock. [ 28.561947] [ 28.570230] [ 28.570230] the existing dependency chain (in reverse order) is: [ 28.577820] [ 28.577820] -> #1 (ashmem_mutex){+.+.}: [ 28.583251] __mutex_lock+0x16f/0x1a80 [ 28.587627] mutex_lock_nested+0x16/0x20 [ 28.592178] ashmem_mmap+0x53/0x410 [ 28.596296] mmap_region+0xa99/0x15a0 [ 28.600585] do_mmap+0x6c0/0xe00 [ 28.604442] vm_mmap_pgoff+0x1de/0x280 [ 28.608820] SyS_mmap_pgoff+0x462/0x5f0 [ 28.613285] SyS_mmap+0x16/0x20 [ 28.617055] do_syscall_64+0x281/0x940 [ 28.621433] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.627114] [ 28.627114] -> #0 (&mm->mmap_sem){++++}: [ 28.632632] lock_acquire+0x1d5/0x580 [ 28.636923] __might_fault+0x13a/0x1d0 [ 28.641304] _copy_from_user+0x2c/0x110 [ 28.645782] ashmem_ioctl+0x438/0x11b0 [ 28.650181] do_vfs_ioctl+0x1b1/0x1520 [ 28.654579] SyS_ioctl+0x8f/0xc0 [ 28.658456] do_syscall_64+0x281/0x940 [ 28.662854] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.668543] [ 28.668543] other info that might help us debug this: [ 28.668543] [ 28.676672] Possible unsafe locking scenario: [ 28.676672] [ 28.682711] CPU0 CPU1 [ 28.687347] ---- ---- [ 28.691978] lock(ashmem_mutex); [ 28.695443] lock(&mm->mmap_sem); [ 28.701471] lock(ashmem_mutex); [ 28.707409] lock(&mm->mmap_sem); [ 28.710916] [ 28.710916] *** DEADLOCK *** [ 28.710916] [ 28.716942] 1 lock held by syzkaller411811/4233: [ 28.721662] #0: (ashmem_mutex){+.+.}, at: [<00000000f5df116b>] ashmem_ioctl+0x3db/0x11b0 [ 28.730043] [ 28.730043] stack backtrace: [ 28.734509] CPU: 0 PID: 4233 Comm: syzkaller411811 Not tainted 4.16.0-rc4+ #345 [ 28.741923] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.751250] Call Trace: [ 28.753817] dump_stack+0x194/0x24d [ 28.757414] ? arch_local_irq_restore+0x53/0x53 [ 28.762057] print_circular_bug.isra.38+0x2cd/0x2dc [ 28.767047] ? save_trace+0xe0/0x2b0 [ 28.770732] __lock_acquire+0x30a8/0x3e00 [ 28.774851] ? ashmem_ioctl+0x3db/0x11b0 [ 28.778886] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.784048] ? __might_sleep+0x95/0x190 [ 28.788001] ? ashmem_ioctl+0x3db/0x11b0 [ 28.792035] ? __mutex_lock+0x16f/0x1a80 [ 28.796065] ? ashmem_ioctl+0x3db/0x11b0 [ 28.800097] ? proc_nr_files+0x60/0x60 [ 28.803951] ? ashmem_ioctl+0x3db/0x11b0 [ 28.807982] ? find_held_lock+0x35/0x1d0 [ 28.812011] ? mutex_lock_io_nested+0x1900/0x1900 [ 28.816826] ? uprobe_mmap+0x15a/0xc90 [ 28.820681] ? lock_downgrade+0x980/0x980 [ 28.824800] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 28.829613] ? find_held_lock+0x35/0x1d0 [ 28.833655] ? lock_downgrade+0x980/0x980 [ 28.837776] ? vma_set_page_prot+0x16b/0x230 [ 28.842157] lock_acquire+0x1d5/0x580 [ 28.846361] ? lock_acquire+0x1d5/0x580 [ 28.850306] ? __might_fault+0xe0/0x1d0 [ 28.854251] ? lock_release+0xa40/0xa40 [ 28.858195] ? check_same_owner+0x320/0x320 [ 28.862487] ? __might_sleep+0x95/0x190 [ 28.866430] __might_fault+0x13a/0x1d0 [ 28.870285] ? __might_fault+0xe0/0x1d0 [ 28.874232] _copy_from_user+0x2c/0x110 [ 28.878176] ashmem_ioctl+0x438/0x11b0 [ 28.882034] ? ashmem_release+0x190/0x190 [ 28.886152] ? check_same_owner+0x320/0x320 [ 28.890446] ? down_read_killable+0x180/0x180 [ 28.894915] ? rcu_note_context_switch+0x710/0x710 [ 28.899823] ? ashmem_release+0x190/0x190 [ 28.903949] do_vfs_ioctl+0x1b1/0x1520 [ 28.907810] ? ioctl_preallocate+0x2b0/0x2b0 [ 28.912190] ? selinux_capable+0x40/0x40 [ 28.916873] ? putname+0xf3/0x130 [ 28.920297] ? fput+0xd2/0x140 [ 28.923462] ? SyS_mmap_pgoff+0x243/0x5f0 [ 28.927579] ? security_file_ioctl+0x7d/0xb0 [ 28.931957] ? security_file_ioctl+0x89/0xb0 [ 28.936335] SyS_ioctl+0x8f/0xc0 [ 28.939670] ? do_vfs_ioctl+0x1520/0x1520 [ 28.943791] do_syscall_64+0x281/0x940 [ 28.947649] ? __do_page_fault+0xc90/0xc90 [ 28.951854] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 28.957358] ? syscall_return_slowpath+0x550/0x550 [ 28.962254] ? syscall_return_slowpath+0x2ac/0x550 [ 28.967155] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 28.972487] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.977298] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.982456] RIP: 0033:0x43fd19 [ 28.985613] RSP: 002b:00007ffd41d2b528 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 [ 28.993287] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd19 [ 29.000526] RDX: 0000000000000000 RSI: 0000000000007709 RDI: 0000000000000003 [ 29.007777] RBP: 00000000006ca018 R08: 00000