[....] Starting enhanced syslogd: rsyslogd[ 13.258848] audit: type=1400 audit(1516178273.453:5): avc: denied { syslog } for pid=3511 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: [ 18.373968] audit: type=1400 audit(1516178278.568:6): avc: denied { map } for pid=3650 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 '10.128.0.27' (ECDSA) to the list of known hosts. executing program [ 24.664219] audit: type=1400 audit(1516178284.859:7): avc: denied { map } for pid=3664 comm="syzkaller552356" path="/root/syzkaller552356112" 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 [ 24.667075] [ 24.690191] audit: type=1400 audit(1516178284.861:8): avc: denied { map } for pid=3664 comm="syzkaller552356" path="/dev/ashmem" dev="devtmpfs" ino=125 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 24.691759] ====================================================== [ 24.691761] WARNING: possible circular locking dependency detected [ 24.691764] 4.15.0-rc8-next-20180117+ #99 Not tainted [ 24.691765] ------------------------------------------------------ [ 24.691767] syzkaller552356/3664 is trying to acquire lock: [ 24.691772] (&sb->s_type->i_mutex_key#11){++++}, at: [<000000007cfa2ba3>] shmem_file_llseek+0xef/0x240 [ 24.755605] [ 24.755605] but task is already holding lock: [ 24.761541] (ashmem_mutex){+.+.}, at: [<0000000027e1881f>] ashmem_llseek+0x56/0x1f0 [ 24.769398] [ 24.769398] which lock already depends on the new lock. [ 24.769398] [ 24.777679] [ 24.777679] the existing dependency chain (in reverse order) is: [ 24.785266] [ 24.785266] -> #2 (ashmem_mutex){+.+.}: [ 24.790697] __mutex_lock+0x16f/0x1a80 [ 24.795074] mutex_lock_nested+0x16/0x20 [ 24.799625] ashmem_mmap+0x53/0x410 [ 24.803743] mmap_region+0xa99/0x15a0 [ 24.808045] do_mmap+0x73c/0xf70 [ 24.811922] vm_mmap_pgoff+0x1de/0x280 [ 24.816300] SyS_mmap_pgoff+0x462/0x5f0 [ 24.820765] SyS_mmap+0x16/0x20 [ 24.824544] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 24.829789] [ 24.829789] -> #1 (&mm->mmap_sem){++++}: [ 24.835314] __might_fault+0x13a/0x1d0 [ 24.839702] _copy_to_user+0x2c/0xc0 [ 24.843908] filldir+0x1a7/0x320 [ 24.847763] dcache_readdir+0x12d/0x5e0 [ 24.852226] iterate_dir+0x1ca/0x530 [ 24.856432] SyS_getdents+0x225/0x450 [ 24.860741] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 24.865985] [ 24.865985] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 24.873255] lock_acquire+0x1d5/0x580 [ 24.878940] down_write+0x87/0x120 [ 24.882973] shmem_file_llseek+0xef/0x240 [ 24.887622] vfs_llseek+0xa2/0xd0 [ 24.891567] ashmem_llseek+0xe7/0x1f0 [ 24.895857] SyS_lseek+0xeb/0x170 [ 24.899805] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 24.905048] [ 24.905048] other info that might help us debug this: [ 24.905048] [ 24.913158] Chain exists of: [ 24.913158] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 24.913158] [ 24.924751] Possible unsafe locking scenario: [ 24.924751] [ 24.930865] CPU0 CPU1 [ 24.935502] ---- ---- [ 24.940136] lock(ashmem_mutex); [ 24.943558] lock(&mm->mmap_sem); [ 24.949582] lock(ashmem_mutex); [ 24.955520] lock(&sb->s_type->i_mutex_key#11); [ 24.960246] [ 24.960246] *** DEADLOCK *** [ 24.960246] [ 24.966272] 1 lock held by syzkaller552356/3664: [ 24.970992] #0: (ashmem_mutex){+.+.}, at: [<0000000027e1881f>] ashmem_llseek+0x56/0x1f0 [ 24.979289] [ 24.979289] stack backtrace: [ 24.983764] CPU: 1 PID: 3664 Comm: syzkaller552356 Not tainted 4.15.0-rc8-next-20180117+ #99 [ 24.992316] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.001641] Call Trace: [ 25.004210] dump_stack+0x194/0x257 [ 25.007814] ? arch_local_irq_restore+0x53/0x53 [ 25.012457] print_circular_bug.isra.37+0x2cd/0x2dc [ 25.017443] ? save_trace+0xe0/0x2b0 [ 25.021127] __lock_acquire+0x30a8/0x3e00 [ 25.025242] ? lock_downgrade+0x980/0x980 [ 25.029361] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 25.034189] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.039351] ? ashmem_llseek+0x56/0x1f0 [ 25.043297] ? lock_release+0xa40/0xa40 [ 25.047239] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.053093] ? vma_set_page_prot+0x16b/0x230 [ 25.057472] ? rcu_note_context_switch+0x710/0x710 [ 25.062370] ? vma_wants_writenotify+0x3b0/0x3b0 [ 25.067104] ? __might_sleep+0x95/0x190 [ 25.071052] ? ashmem_llseek+0x56/0x1f0 [ 25.075001] ? __mutex_lock+0x16f/0x1a80 [ 25.079039] ? ashmem_llseek+0x56/0x1f0 [ 25.082990] ? ashmem_llseek+0x56/0x1f0 [ 25.086937] ? mutex_lock_io_nested+0x1900/0x1900 [ 25.091753] ? vm_mmap_pgoff+0x1ed/0x280 [ 25.095786] ? selinux_mmap_addr+0x1f/0xf0 [ 25.099995] ? userfaultfd_unmap_complete+0x327/0x510 [ 25.105154] ? get_unmapped_area+0x265/0x300 [ 25.109559] lock_acquire+0x1d5/0x580 [ 25.113344] ? lock_acquire+0x1d5/0x580 [ 25.117292] ? shmem_file_llseek+0xef/0x240 [ 25.121588] ? lock_release+0xa40/0xa40 [ 25.125534] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.131396] ? rcu_note_context_switch+0x710/0x710 [ 25.136298] ? __fget_light+0x297/0x380 [ 25.140242] ? __might_sleep+0x95/0x190 [ 25.144189] down_write+0x87/0x120 [ 25.147701] ? shmem_file_llseek+0xef/0x240 [ 25.151993] ? down_read+0x150/0x150 [ 25.155697] ? selinux_capable+0x40/0x40 [ 25.159735] shmem_file_llseek+0xef/0x240 [ 25.163859] ? shmem_free_swap+0x80/0x80 [ 25.167895] vfs_llseek+0xa2/0xd0 [ 25.171338] ashmem_llseek+0xe7/0x1f0 [ 25.175112] ? ashmem_read_iter+0x230/0x230 [ 25.179404] SyS_lseek+0xeb/0x170 [ 25.182830] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.187558] RIP: 0033:0x43fcd9 [ 25.190717] RSP: 002b:00007ffc0944ae08 EFLAGS: 00000217 ORIG_RAX: 0000000000000008 [ 25.199014] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fcd9 [ 25.206256] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000003 [ 25.213496] RBP: 00000000006ca018