[....] Starting enhanced syslogd: rsyslogd[ 12.811763] audit: type=1400 audit(1515564560.076:5): avc: denied { syslog } for pid=3346 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: [ 19.305979] audit: type=1400 audit(1515564566.570:6): avc: denied { map } for pid=3485 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 '10.128.0.49' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 25.520375] audit: type=1400 audit(1515564572.785:7): avc: denied { map } for pid=3500 comm="syzkaller121296" path="/root/syzkaller121296013" 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 executing program [ 25.643537] [ 25.645210] ====================================================== [ 25.645331] audit: type=1400 audit(1515564572.907:8): avc: denied { map } for pid=3500 comm="syzkaller121296" path="/dev/ashmem" dev="devtmpfs" ino=1166 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 25.676211] WARNING: possible circular locking dependency detected [ 25.682496] 4.15.0-rc7+ #165 Not tainted [ 25.686519] ------------------------------------------------------ [ 25.692807] syzkaller121296/3500 is trying to acquire lock: [ 25.698746] (&sb->s_type->i_mutex_key#11){++++}, at: [<0000000072addd43>] shmem_file_llseek+0xef/0x240 [ 25.708256] [ 25.708256] but task is already holding lock: [ 25.714195] (ashmem_mutex){+.+.}, at: [<000000006dc50381>] ashmem_llseek+0x56/0x1f0 [ 25.722051] [ 25.722051] which lock already depends on the new lock. [ 25.722051] [ 25.730333] [ 25.730333] the existing dependency chain (in reverse order) is: [ 25.737917] [ 25.737917] -> #2 (ashmem_mutex){+.+.}: [ 25.743348] __mutex_lock+0x16f/0x1a80 [ 25.747720] mutex_lock_nested+0x16/0x20 [ 25.752266] ashmem_mmap+0x53/0x410 [ 25.756385] mmap_region+0xa99/0x15a0 [ 25.760676] do_mmap+0x6c0/0xe00 [ 25.764536] vm_mmap_pgoff+0x1de/0x280 [ 25.768909] SyS_mmap_pgoff+0x462/0x5f0 [ 25.773371] do_fast_syscall_32+0x3ee/0xf9d [ 25.778177] entry_SYSENTER_compat+0x54/0x63 [ 25.783069] [ 25.783069] -> #1 (&mm->mmap_sem){++++}: [ 25.788587] __might_fault+0x13a/0x1d0 [ 25.792972] _copy_to_user+0x2c/0xc0 [ 25.797178] filldir+0x1a7/0x320 [ 25.801049] dcache_readdir+0x12d/0x5e0 [ 25.805508] iterate_dir+0x1ca/0x530 [ 25.809707] SyS_getdents+0x225/0x450 [ 25.814003] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.819247] [ 25.819247] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 25.825974] lock_acquire+0x1d5/0x580 [ 25.830261] down_write+0x87/0x120 [ 25.834287] shmem_file_llseek+0xef/0x240 [ 25.838927] vfs_llseek+0xa2/0xd0 [ 25.842869] ashmem_llseek+0xe7/0x1f0 [ 25.847155] compat_SyS_lseek+0xeb/0x170 [ 25.851706] do_fast_syscall_32+0x3ee/0xf9d [ 25.856512] entry_SYSENTER_compat+0x54/0x63 [ 25.861403] [ 25.861403] other info that might help us debug this: [ 25.861403] [ 25.869520] Chain exists of: [ 25.869520] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 25.869520] [ 25.881022] Possible unsafe locking scenario: [ 25.881022] [ 25.887044] CPU0 CPU1 [ 25.891681] ---- ---- [ 25.896309] lock(ashmem_mutex); [ 25.899729] lock(&mm->mmap_sem); [ 25.905751] lock(ashmem_mutex); [ 25.911701] lock(&sb->s_type->i_mutex_key#11); [ 25.916423] [ 25.916423] *** DEADLOCK *** [ 25.916423] [ 25.922445] 1 lock held by syzkaller121296/3500: [ 25.927161] #0: (ashmem_mutex){+.+.}, at: [<000000006dc50381>] ashmem_llseek+0x56/0x1f0 [ 25.935452] [ 25.935452] stack backtrace: [ 25.939915] CPU: 0 PID: 3500 Comm: syzkaller121296 Not tainted 4.15.0-rc7+ #165 [ 25.947328] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.956652] Call Trace: [ 25.959215] dump_stack+0x194/0x257 [ 25.962810] ? arch_local_irq_restore+0x53/0x53 [ 25.967448] print_circular_bug.isra.37+0x2cd/0x2dc [ 25.972437] ? save_trace+0xe0/0x2b0 [ 25.976116] __lock_acquire+0x30a8/0x3e00 [ 25.980239] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.985398] ? ashmem_llseek+0x56/0x1f0 [ 25.989341] ? lock_release+0xa40/0xa40 [ 25.993283] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.999134] ? rcu_note_context_switch+0x710/0x710 [ 26.004039] ? check_noncircular+0x20/0x20 [ 26.008248] ? __might_sleep+0x95/0x190 [ 26.012194] ? ashmem_llseek+0x56/0x1f0 [ 26.016162] ? __mutex_lock+0x16f/0x1a80 [ 26.020188] ? ashmem_llseek+0x56/0x1f0 [ 26.024130] ? mmap_region+0x52e/0x15a0 [ 26.028071] ? ashmem_llseek+0x56/0x1f0 [ 26.032023] ? mutex_lock_io_nested+0x1900/0x1900 [ 26.036841] ? find_held_lock+0x35/0x1d0 [ 26.040868] ? check_noncircular+0x20/0x20 [ 26.045077] ? lock_downgrade+0x980/0x980 [ 26.049196] lock_acquire+0x1d5/0x580 [ 26.052969] ? lock_acquire+0x1d5/0x580 [ 26.056912] ? shmem_file_llseek+0xef/0x240 [ 26.061205] ? lock_release+0xa40/0xa40 [ 26.065150] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 26.071004] ? security_mmap_file+0x143/0x180 [ 26.075476] ? rcu_note_context_switch+0x710/0x710 [ 26.080384] ? __fget_light+0x297/0x380 [ 26.084324] ? __might_sleep+0x95/0x190 [ 26.088268] down_write+0x87/0x120 [ 26.091780] ? shmem_file_llseek+0xef/0x240 [ 26.096064] ? down_read+0x150/0x150 [ 26.099744] ? kmem_cache_free+0x267/0x2a0 [ 26.103950] shmem_file_llseek+0xef/0x240 [ 26.108064] ? shmem_free_swap+0x80/0x80 [ 26.112093] vfs_llseek+0xa2/0xd0 [ 26.115512] ashmem_llseek+0xe7/0x1f0 [ 26.119277] ? ashmem_read_iter+0x230/0x230 [ 26.123569] compat_SyS_lseek+0xeb/0x170 [ 26.127596] ? SyS_lseek+0x170/0x170 [ 26.131290] do_fast_syscall_32+0x3ee/0xf9d [ 26.135581] ? do_int80_syscall_32+0x9d0/0x9d0 [ 26.140151] ? kasan_check_read+0x11/0x20 [ 26.144269] ? syscall_return_slowpath+0x550/0x550 [ 26.149168] ? SyS_rt_sigaction+0x94/0x1b0 [ 26.153374] ? SyS_sigprocmask+0x4b0/0x4b0 [ 26.157573] ? SyS_read+0x184/0x220 [ 26.161175] ? sysret32_from_system_call+0x5/0x3b [ 26.165986] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.170798] entry_SYSENTER_compat+0x54/0x63 [ 26.175183] RIP: 0023:0xf7f0bc79 [ 26.178520] RSP: 002b:00000000ffbc129c EFLAGS: 00000282 ORIG_RAX: 0000000000000013 [ 26.186190] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000000 [ 26.193424] RDX: 0000000000