[....] Starting enhanced syslogd: rsyslogd[ 12.431886] audit: type=1400 audit(1515563289.731:5): 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: [ 19.409831] audit: type=1400 audit(1515563296.709:6): 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 '10.128.15.216' (ECDSA) to the list of known hosts. executing program executing program executing program executing program [ 25.609197] audit: type=1400 audit(1515563302.909:7): avc: denied { map } for pid=3499 comm="syzkaller696274" path="/root/syzkaller696274983" 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 [ 25.635181] audit: type=1400 audit(1515563302.909:8): avc: denied { map } for pid=3499 comm="syzkaller696274" path="/dev/ashmem" dev="devtmpfs" ino=8866 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 25.668086] [ 25.669718] ====================================================== [ 25.676002] WARNING: possible circular locking dependency detected [ 25.682286] 4.15.0-rc7+ #165 Not tainted [ 25.686308] ------------------------------------------------------ [ 25.692596] syzkaller696274/3501 is trying to acquire lock: [ 25.698273] (&sb->s_type->i_mutex_key#11){++++}, at: [<000000009bf49635>] shmem_file_llseek+0xef/0x240 [ 25.707784] executing program [ 25.707784] but task is already holding lock: [ 25.713717] (ashmem_mutex){+.+.}, at: [<000000007388b0a1>] ashmem_llseek+0x56/0x1f0 [ 25.721569] [ 25.721569] which lock already depends on the new lock. [ 25.721569] [ 25.729847] [ 25.729847] the existing dependency chain (in reverse order) is: [ 25.737429] [ 25.737429] -> #2 (ashmem_mutex){+.+.}: [ 25.742862] __mutex_lock+0x16f/0x1a80 [ 25.747234] mutex_lock_nested+0x16/0x20 [ 25.751779] ashmem_mmap+0x53/0x410 [ 25.755890] mmap_region+0xa99/0x15a0 [ 25.760173] do_mmap+0x6c0/0xe00 [ 25.764025] vm_mmap_pgoff+0x1de/0x280 [ 25.768396] SyS_mmap_pgoff+0x462/0x5f0 [ 25.772853] do_fast_syscall_32+0x3ee/0xf9d [ 25.777665] entry_SYSENTER_compat+0x54/0x63 [ 25.782558] [ 25.782558] -> #1 (&mm->mmap_sem){++++}: [ 25.788063] __might_fault+0x13a/0x1d0 [ 25.792469] _copy_to_user+0x2c/0xc0 [ 25.796667] filldir+0x1a7/0x320 [ 25.800523] dcache_readdir+0x12d/0x5e0 [ 25.804993] iterate_dir+0x1ca/0x530 [ 25.809190] SyS_getdents+0x225/0x450 [ 25.813473] entry_SYSCALL_64_fastpath+0x23/0x9a [ 25.818711] [ 25.818711] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 25.825432] lock_acquire+0x1d5/0x580 [ 25.829721] down_write+0x87/0x120 [ 25.833744] shmem_file_llseek+0xef/0x240 [ 25.838374] vfs_llseek+0xa2/0xd0 [ 25.842311] ashmem_llseek+0xe7/0x1f0 [ 25.846594] compat_SyS_lseek+0xeb/0x170 [ 25.851137] do_fast_syscall_32+0x3ee/0xf9d [ 25.855949] entry_SYSENTER_compat+0x54/0x63 [ 25.860842] [ 25.860842] other info that might help us debug this: [ 25.860842] [ 25.868944] Chain exists of: [ 25.868944] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 25.868944] [ 25.880444] Possible unsafe locking scenario: [ 25.880444] [ 25.886463] CPU0 CPU1 [ 25.891322] ---- ---- [ 25.895951] lock(ashmem_mutex); [ 25.899371] lock(&mm->mmap_sem); [ 25.905390] lock(ashmem_mutex); [ 25.911323] lock(&sb->s_type->i_mutex_key#11); [ 25.916041] [ 25.916041] *** DEADLOCK *** [ 25.916041] [ 25.922068] 1 lock held by syzkaller696274/3501: [ 25.926784] #0: (ashmem_mutex){+.+.}, at: [<000000007388b0a1>] ashmem_llseek+0x56/0x1f0 [ 25.935082] [ 25.935082] stack backtrace: [ 25.939547] CPU: 0 PID: 3501 Comm: syzkaller696274 Not tainted 4.15.0-rc7+ #165 [ 25.946958] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.956285] Call Trace: [ 25.958839] dump_stack+0x194/0x257 [ 25.962429] ? arch_local_irq_restore+0x53/0x53 [ 25.967064] print_circular_bug.isra.37+0x2cd/0x2dc [ 25.972041] ? save_trace+0xe0/0x2b0 [ 25.975717] __lock_acquire+0x30a8/0x3e00 [ 25.979832] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.984986] ? ashmem_llseek+0x56/0x1f0 [ 25.988935] ? lock_release+0xa40/0xa40 [ 25.992874] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.998724] ? do_futex+0x86f/0x22a0 [ 26.002401] ? rcu_note_context_switch+0x710/0x710 [ 26.007296] ? __might_sleep+0x95/0x190 [ 26.011232] ? ashmem_llseek+0x56/0x1f0 [ 26.015184] ? __mutex_lock+0x16f/0x1a80 [ 26.019206] ? ashmem_llseek+0x56/0x1f0 [ 26.023145] ? __fget+0x333/0x570 [ 26.026561] ? lock_downgrade+0x980/0x980 [ 26.030671] ? ashmem_llseek+0x56/0x1f0 [ 26.034609] ? mutex_lock_io_nested+0x1900/0x1900 [ 26.039413] ? __lock_is_held+0xb6/0x140 [ 26.043435] ? check_noncircular+0x20/0x20 [ 26.047632] ? __fget+0x35c/0x570 [ 26.051234] lock_acquire+0x1d5/0x580 [ 26.054999] ? lock_acquire+0x1d5/0x580 [ 26.058940] ? shmem_file_llseek+0xef/0x240 [ 26.063237] ? lock_release+0xa40/0xa40 [ 26.067184] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 26.073034] ? security_mmap_file+0x143/0x180 [ 26.077493] ? rcu_note_context_switch+0x710/0x710 [ 26.082387] ? __fget_light+0x297/0x380 [ 26.086326] ? __might_sleep+0x95/0x190 [ 26.090263] down_write+0x87/0x120 [ 26.093766] ? shmem_file_llseek+0xef/0x240 [ 26.098050] ? down_read+0x150/0x150 [ 26.101727] shmem_file_llseek+0xef/0x240 [ 26.105837] ? shmem_free_swap+0x80/0x80 [ 26.109862] vfs_llseek+0xa2/0xd0 [ 26.113280] ashmem_llseek+0xe7/0x1f0 [ 26.117045] ? ashmem_read_iter+0x230/0x230 [ 26.121329] compat_SyS_lseek+0xeb/0x170 [ 26.125351] ? SyS_lseek+0x170/0x170 [ 26.129042] do_fast_syscall_32+0x3ee/0xf9d [ 26.133328] ? do_raw_spin_trylock+0x190/0x190 [ 26.137874] ? do_int80_syscall_32+0x9d0/0x9d0 [ 26.142422] ? syscall_return_slowpath+0x2ad/0x550 [ 26.147319] ? prepare_exit_to_usermode+0x340/0x340 [ 26.152299] ? sysret32_from_system_call+0x5/0x3b [ 26.157118] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.161928] entry_SYSENTER_compat+0x54/0x63 [ 26.166303] RIP: 0023:0xf7ff5c79 [ 26.169632] RSP: 002b:00000000f7fd01fc EFLAGS: 00000293 ORIG_RAX: 0000000000000013 [ 26.177305] RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000000000 [ 26.184554] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 [ 26.191928] RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000 [ 26.199166] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 26.206399] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program