[....] Starting enhanced syslogd: rsyslogd[ 12.291946] audit: type=1400 audit(1515563223.823:5): avc: denied { syslog } for pid=3341 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: [ 16.632998] audit: type=1400 audit(1515563228.164:6): avc: denied { map } for pid=3479 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 '10.128.0.32' (ECDSA) to the list of known hosts. executing program [ 22.842713] audit: type=1400 audit(1515563234.374:7): avc: denied { map } for pid=3493 comm="syzkaller223469" path="/root/syzkaller223469276" 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 executing program executing program executing program executing program executing program executing program executing program [ 22.869130] audit: type=1400 audit(1515563234.374:8): avc: denied { map } for pid=3493 comm="syzkaller223469" path="/dev/ashmem" dev="devtmpfs" ino=8968 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 22.930288] [ 22.931917] ====================================================== [ 22.938198] WARNING: possible circular locking dependency detected [ 22.944479] 4.15.0-rc7+ #255 Not tainted [ 22.948514] ------------------------------------------------------ [ 22.954801] syzkaller223469/3495 is trying to acquire lock: [ 22.960477] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000ea9205c2>] shmem_file_llseek+0xef/0x240 [ 22.969989] [ 22.969989] but task is already holding lock: executing program [ 22.975928] (ashmem_mutex){+.+.}, at: [<000000003462001f>] ashmem_llseek+0x56/0x1f0 [ 22.983782] [ 22.983782] which lock already depends on the new lock. [ 22.983782] [ 22.992061] [ 22.992061] the existing dependency chain (in reverse order) is: [ 22.999644] [ 22.999644] -> #2 (ashmem_mutex){+.+.}: [ 23.005073] __mutex_lock+0x16f/0x1a80 [ 23.009446] mutex_lock_nested+0x16/0x20 [ 23.013993] ashmem_mmap+0x53/0x410 [ 23.018105] mmap_region+0xa99/0x15a0 [ 23.022394] do_mmap+0x6c0/0xe00 [ 23.026249] vm_mmap_pgoff+0x1de/0x280 [ 23.030620] SyS_mmap_pgoff+0x462/0x5f0 [ 23.035085] SyS_mmap+0x16/0x20 [ 23.038849] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.044086] [ 23.044086] -> #1 (&mm->mmap_sem){++++}: [ 23.049590] __might_fault+0x13a/0x1d0 [ 23.053980] _copy_to_user+0x2c/0xc0 [ 23.058177] filldir+0x1a7/0x320 [ 23.062027] dcache_readdir+0x12d/0x5e0 [ 23.066485] iterate_dir+0x1ca/0x530 [ 23.070683] SyS_getdents+0x225/0x450 [ 23.074981] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.080219] [ 23.080219] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 23.086945] lock_acquire+0x1d5/0x580 [ 23.091325] down_write+0x87/0x120 [ 23.095352] shmem_file_llseek+0xef/0x240 [ 23.099986] vfs_llseek+0xa2/0xd0 [ 23.103923] ashmem_llseek+0xe7/0x1f0 [ 23.108215] SyS_lseek+0xeb/0x170 [ 23.112153] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.117388] [ 23.117388] other info that might help us debug this: [ 23.117388] [ 23.125492] Chain exists of: [ 23.125492] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 23.125492] [ 23.136992] Possible unsafe locking scenario: [ 23.136992] [ 23.143015] CPU0 CPU1 [ 23.147643] ---- ---- [ 23.152272] lock(ashmem_mutex); [ 23.155689] lock(&mm->mmap_sem); [ 23.161714] lock(ashmem_mutex); [ 23.167652] lock(&sb->s_type->i_mutex_key#11); [ 23.172389] [ 23.172389] *** DEADLOCK *** [ 23.172389] [ 23.178413] 1 lock held by syzkaller223469/3495: [ 23.183127] #0: (ashmem_mutex){+.+.}, at: [<000000003462001f>] ashmem_llseek+0x56/0x1f0 [ 23.191416] [ 23.191416] stack backtrace: [ 23.195875] CPU: 0 PID: 3495 Comm: syzkaller223469 Not tainted 4.15.0-rc7+ #255 [ 23.203288] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.212604] Call Trace: [ 23.215173] dump_stack+0x194/0x257 [ 23.218766] ? arch_local_irq_restore+0x53/0x53 [ 23.223414] print_circular_bug.isra.37+0x2cd/0x2dc [ 23.228399] ? save_trace+0xe0/0x2b0 [ 23.232082] __lock_acquire+0x30a8/0x3e00 [ 23.236197] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.241350] ? ashmem_llseek+0x56/0x1f0 [ 23.245287] ? lock_release+0xa40/0xa40 [ 23.249224] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.255075] ? do_futex+0x86f/0x22a0 [ 23.258762] ? rcu_note_context_switch+0x710/0x710 [ 23.263654] ? __might_sleep+0x95/0x190 [ 23.267591] ? ashmem_llseek+0x56/0x1f0 [ 23.271530] ? __mutex_lock+0x16f/0x1a80 [ 23.275554] ? ashmem_llseek+0x56/0x1f0 [ 23.279491] ? lock_downgrade+0x980/0x980 [ 23.283601] ? ashmem_llseek+0x56/0x1f0 [ 23.287535] ? lock_release+0xa40/0xa40 [ 23.291477] ? mutex_lock_io_nested+0x1900/0x1900 [ 23.296282] ? __lock_is_held+0xb6/0x140 [ 23.300309] ? __fget+0x35c/0x570 [ 23.303728] ? userfaultfd_unmap_complete+0x327/0x510 [ 23.308884] lock_acquire+0x1d5/0x580 [ 23.312646] ? lock_acquire+0x1d5/0x580 [ 23.316585] ? shmem_file_llseek+0xef/0x240 [ 23.320876] ? lock_release+0xa40/0xa40 [ 23.324815] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.330665] ? rcu_note_context_switch+0x710/0x710 [ 23.335555] ? __fget_light+0x297/0x380 [ 23.339492] ? __might_sleep+0x95/0x190 [ 23.343436] down_write+0x87/0x120 [ 23.346938] ? shmem_file_llseek+0xef/0x240 [ 23.351224] ? down_read+0x150/0x150 [ 23.354903] shmem_file_llseek+0xef/0x240 [ 23.359018] ? shmem_free_swap+0x80/0x80 [ 23.363044] vfs_llseek+0xa2/0xd0 [ 23.366462] ashmem_llseek+0xe7/0x1f0 [ 23.370229] ? ashmem_read_iter+0x230/0x230 [ 23.374516] SyS_lseek+0xeb/0x170 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.377940] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.382659] RIP: 0033:0x445519 [ 23.385813] RSP: 002b:00007f60f5b34da8 EFLAGS: 00000293 ORIG_RAX: 0000000000000008 [ 23.393483] RAX: ffffffffffffffda RBX: 00007f60f5b35700 RCX: 0000000000445519 [ 23.400716] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000013 [ 23.407957] RBP: 00007ffdfed316a0 R08: 0000000000000000 R09: 0000000000000000 [ 23.415192] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 23.422426] R13: 00007ffdfed315ff R14: 00007f60f5b359c0 R15: 0000000000000005 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program