[....] Starting enhanced syslogd: rsyslogd[ 12.922935] audit: type=1400 audit(1515561822.815:5): avc: denied { syslog } for pid=3340 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: [ 18.260929] audit: type=1400 audit(1515561828.153:6): avc: denied { map } for pid=3481 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 '10.128.0.51' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 24.762954] audit: type=1400 audit(1515561834.655:7): avc: denied { map } for pid=3495 comm="syzkaller491750" path="/root/syzkaller491750084" 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 [ 24.884614] [ 24.884707] audit: type=1400 audit(1515561834.776:8): avc: denied { map } for pid=3495 comm="syzkaller491750" path="/dev/ashmem" dev="devtmpfs" ino=1178 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 24.910970] ====================================================== [ 24.917265] WARNING: possible circular locking dependency detected [ 24.923551] 4.15.0-rc7+ #255 Not tainted [ 24.927587] ------------------------------------------------------ [ 24.933874] syzkaller491750/3495 is trying to acquire lock: [ 24.939550] (&sb->s_type->i_mutex_key#11){++++}, at: [<000000008fab0d76>] shmem_file_llseek+0xef/0x240 [ 24.949063] [ 24.949063] but task is already holding lock: [ 24.954998] (ashmem_mutex){+.+.}, at: [<000000000fb2146b>] ashmem_llseek+0x56/0x1f0 [ 24.962864] [ 24.962864] which lock already depends on the new lock. [ 24.962864] [ 24.971151] [ 24.971151] the existing dependency chain (in reverse order) is: [ 24.978735] [ 24.978735] -> #2 (ashmem_mutex){+.+.}: [ 24.984163] __mutex_lock+0x16f/0x1a80 [ 24.988542] mutex_lock_nested+0x16/0x20 [ 24.993089] ashmem_mmap+0x53/0x410 [ 24.997211] mmap_region+0xa99/0x15a0 [ 25.001495] do_mmap+0x6c0/0xe00 [ 25.005353] vm_mmap_pgoff+0x1de/0x280 [ 25.009728] SyS_mmap_pgoff+0x462/0x5f0 [ 25.014190] SyS_mmap+0x16/0x20 [ 25.017959] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.023206] [ 25.023206] -> #1 (&mm->mmap_sem){++++}: [ 25.028715] __might_fault+0x13a/0x1d0 [ 25.033091] _copy_to_user+0x2c/0xc0 [ 25.037378] filldir+0x1a7/0x320 [ 25.041230] dcache_readdir+0x12d/0x5e0 [ 25.045713] iterate_dir+0x1ca/0x530 [ 25.049922] SyS_getdents+0x225/0x450 [ 25.054209] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.059448] [ 25.059448] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 25.066183] lock_acquire+0x1d5/0x580 [ 25.070478] down_write+0x87/0x120 [ 25.074507] shmem_file_llseek+0xef/0x240 [ 25.079148] vfs_llseek+0xa2/0xd0 [ 25.083091] ashmem_llseek+0xe7/0x1f0 [ 25.087376] SyS_lseek+0xeb/0x170 [ 25.091317] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.096563] [ 25.096563] other info that might help us debug this: [ 25.096563] [ 25.104670] Chain exists of: [ 25.104670] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 25.104670] [ 25.116176] Possible unsafe locking scenario: [ 25.116176] [ 25.122197] CPU0 CPU1 [ 25.126825] ---- ---- [ 25.131453] lock(ashmem_mutex); [ 25.134871] lock(&mm->mmap_sem); [ 25.140893] lock(ashmem_mutex); [ 25.146828] lock(&sb->s_type->i_mutex_key#11); [ 25.151548] [ 25.151548] *** DEADLOCK *** [ 25.151548] [ 25.157580] 1 lock held by syzkaller491750/3495: [ 25.162299] #0: (ashmem_mutex){+.+.}, at: [<000000000fb2146b>] ashmem_llseek+0x56/0x1f0 [ 25.170589] [ 25.170589] stack backtrace: [ 25.175053] CPU: 0 PID: 3495 Comm: syzkaller491750 Not tainted 4.15.0-rc7+ #255 [ 25.182463] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.191786] Call Trace: [ 25.194345] dump_stack+0x194/0x257 [ 25.197941] ? arch_local_irq_restore+0x53/0x53 [ 25.202582] print_circular_bug.isra.37+0x2cd/0x2dc [ 25.207566] ? save_trace+0xe0/0x2b0 [ 25.211258] __lock_acquire+0x30a8/0x3e00 [ 25.215376] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.220533] ? ashmem_llseek+0x56/0x1f0 [ 25.224472] ? lock_release+0xa40/0xa40 [ 25.228413] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.234266] ? rcu_note_context_switch+0x710/0x710 [ 25.239162] ? vma_wants_writenotify+0x3b0/0x3b0 [ 25.243886] ? __might_sleep+0x95/0x190 [ 25.247829] ? ashmem_llseek+0x56/0x1f0 [ 25.251772] ? __mutex_lock+0x16f/0x1a80 [ 25.255797] ? ashmem_llseek+0x56/0x1f0 [ 25.259740] ? mmap_region+0x52e/0x15a0 [ 25.263694] ? ashmem_llseek+0x56/0x1f0 [ 25.267634] ? mutex_lock_io_nested+0x1900/0x1900 [ 25.272455] ? vm_mmap_pgoff+0x1ed/0x280 [ 25.276484] ? userfaultfd_unmap_complete+0x327/0x510 [ 25.281653] lock_acquire+0x1d5/0x580 [ 25.285421] ? lock_acquire+0x1d5/0x580 [ 25.289372] ? shmem_file_llseek+0xef/0x240 [ 25.293664] ? lock_release+0xa40/0xa40 [ 25.297605] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.303457] ? rcu_note_context_switch+0x710/0x710 [ 25.308362] ? __fget_light+0x297/0x380 [ 25.312303] ? __might_sleep+0x95/0x190 [ 25.316246] down_write+0x87/0x120 [ 25.319757] ? shmem_file_llseek+0xef/0x240 [ 25.324046] ? down_read+0x150/0x150 [ 25.327729] ? selinux_capable+0x40/0x40 [ 25.331758] shmem_file_llseek+0xef/0x240 [ 25.335871] ? shmem_free_swap+0x80/0x80 [ 25.339900] vfs_llseek+0xa2/0xd0 [ 25.343320] ashmem_llseek+0xe7/0x1f0 [ 25.347088] ? ashmem_read_iter+0x230/0x230 [ 25.351376] SyS_lseek+0xeb/0x170 [ 25.354795] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.359529] RIP: 0033:0x444ac9 [ 25.362687] RSP: 002b:00007fffaa717778 EFLAGS: 00000217 ORIG_RAX: 0000000000000008 [ 25.370359] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000444ac9 [ 25.377597] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000004 [ 25.384834] RBP: 00