[....] Starting enhanced syslogd: rsyslogd[ 17.232164] audit: type=1400 audit(1518852329.468:5): avc: denied { syslog } for pid=4067 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 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: [ 19.712330] audit: type=1400 audit(1518852331.949:6): avc: denied { map } for pid=4206 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 '10.128.0.43' (ECDSA) to the list of known hosts. executing program [ 26.001199] audit: type=1400 audit(1518852338.237:7): avc: denied { map } for pid=4220 comm="syzkaller474356" path="/root/syzkaller474356992" 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 [ 26.004663] [ 26.027137] audit: type=1400 audit(1518852338.241:8): avc: denied { map } for pid=4220 comm="syzkaller474356" path="/dev/ashmem" dev="devtmpfs" ino=1165 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 26.028693] ====================================================== [ 26.028695] WARNING: possible circular locking dependency detected [ 26.028700] 4.16.0-rc1+ #226 Not tainted [ 26.028702] ------------------------------------------------------ [ 26.028708] syzkaller474356/4220 is trying to acquire lock: [ 26.081940] (&sb->s_type->i_mutex_key#11){++++}, at: [<0000000012ce78de>] shmem_file_llseek+0xef/0x240 [ 26.091469] [ 26.091469] but task is already holding lock: [ 26.097421] (ashmem_mutex){+.+.}, at: [<000000003484150b>] ashmem_llseek+0x56/0x1f0 [ 26.105281] [ 26.105281] which lock already depends on the new lock. [ 26.105281] [ 26.113564] [ 26.113564] the existing dependency chain (in reverse order) is: [ 26.121152] [ 26.121152] -> #2 (ashmem_mutex){+.+.}: [ 26.126580] __mutex_lock+0x16f/0x1a80 [ 26.130958] mutex_lock_nested+0x16/0x20 [ 26.135507] ashmem_mmap+0x53/0x410 [ 26.139624] mmap_region+0xa99/0x15a0 [ 26.143913] do_mmap+0x6c0/0xe00 [ 26.147768] vm_mmap_pgoff+0x1de/0x280 [ 26.152146] SyS_mmap_pgoff+0x462/0x5f0 [ 26.156613] do_fast_syscall_32+0x3ec/0xf9f [ 26.161426] entry_SYSENTER_compat+0x70/0x7f [ 26.166375] [ 26.166375] -> #1 (&mm->mmap_sem){++++}: [ 26.171890] __might_fault+0x13a/0x1d0 [ 26.176267] _copy_to_user+0x2c/0xc0 [ 26.180478] filldir+0x1a7/0x320 [ 26.184335] dcache_readdir+0x12d/0x5e0 [ 26.188806] iterate_dir+0x1ca/0x530 [ 26.193011] SyS_getdents+0x225/0x450 [ 26.197311] do_syscall_64+0x280/0x940 [ 26.201688] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 26.207365] [ 26.207365] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 26.214095] lock_acquire+0x1d5/0x580 [ 26.218383] down_write+0x87/0x120 [ 26.222421] shmem_file_llseek+0xef/0x240 [ 26.227056] vfs_llseek+0xa2/0xd0 [ 26.230998] ashmem_llseek+0xe7/0x1f0 [ 26.235286] compat_SyS_lseek+0xeb/0x170 [ 26.239836] do_fast_syscall_32+0x3ec/0xf9f [ 26.244648] entry_SYSENTER_compat+0x70/0x7f [ 26.249541] [ 26.249541] other info that might help us debug this: [ 26.249541] [ 26.257655] Chain exists of: [ 26.257655] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 26.257655] [ 26.269158] Possible unsafe locking scenario: [ 26.269158] [ 26.275182] CPU0 CPU1 [ 26.279818] ---- ---- [ 26.284450] lock(ashmem_mutex); [ 26.287877] lock(&mm->mmap_sem); [ 26.293901] lock(ashmem_mutex); [ 26.299839] lock(&sb->s_type->i_mutex_key#11); [ 26.304562] [ 26.304562] *** DEADLOCK *** [ 26.304562] [ 26.310587] 1 lock held by syzkaller474356/4220: [ 26.315309] #0: (ashmem_mutex){+.+.}, at: [<000000003484150b>] ashmem_llseek+0x56/0x1f0 [ 26.323603] [ 26.323603] stack backtrace: [ 26.328068] CPU: 1 PID: 4220 Comm: syzkaller474356 Not tainted 4.16.0-rc1+ #226 [ 26.335482] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.344802] Call Trace: [ 26.347363] dump_stack+0x194/0x257 [ 26.350960] ? arch_local_irq_restore+0x53/0x53 [ 26.355603] print_circular_bug.isra.38+0x2cd/0x2dc [ 26.360586] ? save_trace+0xe0/0x2b0 [ 26.364277] __lock_acquire+0x30a8/0x3e00 [ 26.368396] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 26.373553] ? ashmem_llseek+0x56/0x1f0 [ 26.377495] ? lock_release+0xa40/0xa40 [ 26.381439] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 26.387296] ? rcu_note_context_switch+0x710/0x710 [ 26.392197] ? vma_set_page_prot+0x16b/0x230 [ 26.396573] ? __might_sleep+0x95/0x190 [ 26.400517] ? ashmem_llseek+0x56/0x1f0 [ 26.404459] ? __mutex_lock+0x16f/0x1a80 [ 26.408499] ? ashmem_llseek+0x56/0x1f0 [ 26.412443] ? mmap_region+0x52e/0x15a0 [ 26.416384] ? ashmem_llseek+0x56/0x1f0 [ 26.420327] ? mutex_lock_io_nested+0x1900/0x1900 [ 26.425137] ? find_held_lock+0x35/0x1d0 [ 26.429170] ? lock_downgrade+0x980/0x980 [ 26.433288] lock_acquire+0x1d5/0x580 [ 26.437060] ? lock_acquire+0x1d5/0x580 [ 26.441004] ? shmem_file_llseek+0xef/0x240 [ 26.445300] ? lock_release+0xa40/0xa40 [ 26.449244] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 26.455101] ? security_mmap_file+0x143/0x180 [ 26.459566] ? rcu_note_context_switch+0x710/0x710 [ 26.464468] ? __fget_light+0x2b2/0x3c0 [ 26.468414] ? __might_sleep+0x95/0x190 [ 26.472363] down_write+0x87/0x120 [ 26.475873] ? shmem_file_llseek+0xef/0x240 [ 26.480163] ? down_read+0x150/0x150 [ 26.483848] ? kmem_cache_free+0x258/0x2a0 [ 26.488054] shmem_file_llseek+0xef/0x240 [ 26.492173] ? shmem_free_swap+0x80/0x80 [ 26.496201] vfs_llseek+0xa2/0xd0 [ 26.499625] ashmem_llseek+0xe7/0x1f0 [ 26.503396] ? ashmem_read_iter+0x230/0x230 [ 26.507686] compat_SyS_lseek+0xeb/0x170 [ 26.511714] ? SyS_lseek+0x170/0x170 [ 26.515398] do_fast_syscall_32+0x3ec/0xf9f [ 26.519707] ? do_int80_syscall_32+0x9c0/0x9c0 [ 26.524259] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.528994] ? syscall_return_slowpath+0x550/0x550 [ 26.533895] ? syscall_return_slowpath+0x2ac/0x550 [ 26.538793] ? prepare_exit_to_usermode+0x350/0x350 [ 26.543778] ? sysret32_from_system_call+0x5/0x3c [ 26.548591] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.553410] entry_SYSENTER_compat+0x70/0x7f [ 26.557787] RIP: 0023:0xf7f80c79 [ 26.561119] RSP: 002b:00000000fffd956c EFLAGS: 00000286 ORIG_RAX: 0000000000000013 [ 26.568794] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000 [ 26.576031] RDX: 0000000000000003 RSI: 00000000080ea00c RDI: 000000000000003f [ 26.583272] RBP: 0000000000001000 R08: 0000000000000000 R09: 0000000000000000 [ 26.590510] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 26.597754] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000