[....] Starting enhanced syslogd: rsyslogd[ 11.607197] audit: type=1400 audit(1515560901.923:5): avc: denied { syslog } for pid=3344 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: [ 19.298154] audit: type=1400 audit(1515560909.613:6): avc: denied { map } for pid=3483 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 '10.128.15.196' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 25.471378] audit: type=1400 audit(1515560915.787:7): avc: denied { map } for pid=3498 comm="syzkaller051776" path="/root/syzkaller051776737" 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 [ 25.591474] [ 25.593124] ====================================================== [ 25.593560] audit: type=1400 audit(1515560915.906:8): avc: denied { map } for pid=3498 comm="syzkaller051776" path="/dev/ashmem" dev="devtmpfs" ino=8984 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 25.624104] WARNING: possible circular locking dependency detected [ 25.630401] 4.15.0-rc6-mm1+ #52 Not tainted [ 25.634690] ------------------------------------------------------ [ 25.640976] syzkaller051776/3498 is trying to acquire lock: [ 25.646648] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000be95fd7e>] shmem_file_llseek+0xef/0x240 [ 25.656155] [ 25.656155] but task is already holding lock: [ 25.662089] (ashmem_mutex){+.+.}, at: [<000000008bbe76b3>] ashmem_llseek+0x56/0x1f0 [ 25.669940] [ 25.669940] which lock already depends on the new lock. [ 25.669940] [ 25.678220] [ 25.678220] the existing dependency chain (in reverse order) is: [ 25.685806] [ 25.685806] -> #2 (ashmem_mutex){+.+.}: [ 25.691234] __mutex_lock+0x16f/0x1a80 [ 25.695611] mutex_lock_nested+0x16/0x20 [ 25.700168] ashmem_mmap+0x53/0x410 [ 25.704284] mmap_region+0xa99/0x15a0 [ 25.708567] do_mmap+0x73c/0xf70 [ 25.712420] vm_mmap_pgoff+0x1de/0x280 [ 25.716796] SyS_mmap_pgoff+0x462/0x5f0 [ 25.721257] SyS_mmap+0x16/0x20 [ 25.725023] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.730261] [ 25.730261] -> #1 (&mm->mmap_sem){++++}: [ 25.735778] __might_fault+0x13a/0x1d0 [ 25.740152] _copy_to_user+0x2c/0xc0 [ 25.744351] filldir+0x1a7/0x320 [ 25.748202] dcache_readdir+0x12d/0x5e0 [ 25.752659] iterate_dir+0x1ca/0x530 [ 25.756857] SyS_getdents+0x225/0x450 [ 25.761142] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.766379] [ 25.766379] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 25.773112] lock_acquire+0x1d5/0x580 [ 25.777401] down_write+0x87/0x120 [ 25.781434] shmem_file_llseek+0xef/0x240 [ 25.786071] vfs_llseek+0xa2/0xd0 [ 25.790013] ashmem_llseek+0xe7/0x1f0 [ 25.794304] SyS_lseek+0xeb/0x170 [ 25.798243] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.803485] [ 25.803485] other info that might help us debug this: [ 25.803485] [ 25.811589] Chain exists of: [ 25.811589] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 25.811589] [ 25.823089] Possible unsafe locking scenario: [ 25.823089] [ 25.829108] CPU0 CPU1 [ 25.833738] ---- ---- [ 25.838366] lock(ashmem_mutex); [ 25.841782] lock(&mm->mmap_sem); [ 25.847802] lock(ashmem_mutex); [ 25.853736] lock(&sb->s_type->i_mutex_key#11); [ 25.858457] [ 25.858457] *** DEADLOCK *** [ 25.858457] [ 25.864568] 1 lock held by syzkaller051776/3498: [ 25.869300] #0: (ashmem_mutex){+.+.}, at: [<000000008bbe76b3>] ashmem_llseek+0x56/0x1f0 [ 25.877589] [ 25.877589] stack backtrace: [ 25.882052] CPU: 1 PID: 3498 Comm: syzkaller051776 Not tainted 4.15.0-rc6-mm1+ #52 [ 25.889725] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.899050] Call Trace: [ 25.901606] dump_stack+0x194/0x257 [ 25.905199] ? arch_local_irq_restore+0x53/0x53 [ 25.909835] print_circular_bug.isra.37+0x2cd/0x2dc [ 25.914821] ? save_trace+0xe0/0x2b0 [ 25.918500] __lock_acquire+0x30a8/0x3e00 [ 25.922619] ? lock_downgrade+0x980/0x980 [ 25.926732] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 25.931542] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.936698] ? ashmem_llseek+0x56/0x1f0 [ 25.940640] ? lock_release+0xa40/0xa40 [ 25.944580] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.950430] ? vma_set_page_prot+0x16b/0x230 [ 25.954805] ? rcu_note_context_switch+0x710/0x710 [ 25.959697] ? vma_wants_writenotify+0x3b0/0x3b0 [ 25.964418] ? __might_sleep+0x95/0x190 [ 25.968357] ? ashmem_llseek+0x56/0x1f0 [ 25.972298] ? __mutex_lock+0x16f/0x1a80 [ 25.976324] ? ashmem_llseek+0x56/0x1f0 [ 25.980270] ? ashmem_llseek+0x56/0x1f0 [ 25.984216] ? mutex_lock_io_nested+0x1900/0x1900 [ 25.989029] ? vm_mmap_pgoff+0x1ed/0x280 [ 25.993057] ? selinux_mmap_addr+0x1f/0xf0 [ 25.997261] ? userfaultfd_unmap_complete+0x327/0x510 [ 26.002415] ? get_unmapped_area+0x265/0x300 [ 26.006792] lock_acquire+0x1d5/0x580 [ 26.010565] ? lock_acquire+0x1d5/0x580 [ 26.014505] ? shmem_file_llseek+0xef/0x240 [ 26.018793] ? lock_release+0xa40/0xa40 [ 26.022734] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 26.028591] ? rcu_note_context_switch+0x710/0x710 [ 26.033489] ? __fget_light+0x297/0x380 [ 26.037441] ? __might_sleep+0x95/0x190 [ 26.041383] down_write+0x87/0x120 [ 26.044890] ? shmem_file_llseek+0xef/0x240 [ 26.049174] ? down_read+0x150/0x150 [ 26.052855] ? selinux_capable+0x40/0x40 [ 26.056880] shmem_file_llseek+0xef/0x240 [ 26.060991] ? shmem_free_swap+0x80/0x80 [ 26.065021] vfs_llseek+0xa2/0xd0 [ 26.068441] ashmem_llseek+0xe7/0x1f0 [ 26.072207] ? ashmem_read_iter+0x230/0x230 [ 26.076499] SyS_lseek+0xeb/0x170 [ 26.079926] entry_SYSCALL_64_fastpath+0x23/0x9a [ 26.084652] RIP: 0033:0x444ac9 [ 26.087806] RSP: 002b:00007ffeff760128 EFLAGS: 00000217 ORIG_RAX: