[....] Starting enhanced syslogd: rsyslogd[ 6.198467] audit: type=1400 audit(1513736743.990:5): avc: denied { syslog } for pid=2976 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: [ 21.589690] audit: type=1400 audit(1513736759.381:6): avc: denied { map } for pid=3115 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 'ci-upstream-next-kasan-gce-2,10.128.15.226' (ECDSA) to the list of known hosts. net.ipv6.conf.syz5.accept_dad = 0 net.ipv6.conf.syz3.accept_dad = 0 net.ipv6.conf.syz1.accept_dad = 0 net.ipv6.conf.syz3.router_solicitations = 0 net.ipv6.conf.syz5.router_solicitations = 0 net.ipv6.conf.syz1.router_solicitations = 0 net.ipv6.conf.syz7.accept_dad = 0 net.ipv6.conf.syz6.accept_dad = 0 net.ipv6.conf.syz2.accept_dad = 0 net.ipv6.conf.syz7.router_solicitations = 0 net.ipv6.conf.syz4.accept_dad = 0 net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz6.router_solicitations = 0 net.ipv6.conf.syz2.router_solicitations = 0 net.ipv6.conf.syz0.router_solicitations = 0 net.ipv6.conf.syz4.router_solicitations = 0 [ 27.388062] audit: type=1400 audit(1513736765.179:7): avc: denied { map } for pid=3129 comm="syzkaller687838" path="/root/syzkaller687838288" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.560612] [ 31.562251] ====================================================== [ 31.568543] WARNING: possible circular locking dependency detected [ 31.574828] 4.15.0-rc3-next-20171214+ #67 Not tainted [ 31.579978] ------------------------------------------------------ [ 31.586259] syzkaller687838/4818 is trying to acquire lock: [ 31.591941] (&p->lock){+.+.}, at: [<0000000040844d02>] seq_read+0x41/0x520 [ 31.599017] [ 31.599017] but task is already holding lock: [ 31.604950] (&pipe->mutex/1){+.+.}, at: [<00000000deb3c5e2>] pipe_lock+0x29/0x40 [ 31.612546] [ 31.612546] which lock already depends on the new lock. [ 31.612546] [ 31.620825] [ 31.620825] the existing dependency chain (in reverse order) is: [ 31.628408] [ 31.628408] -> #2 (&pipe->mutex/1){+.+.}: [ 31.634008] __mutex_lock+0x6b/0xa00 [ 31.638203] mutex_lock_nested+0x16/0x20 [ 31.642747] fifo_open+0x7d/0x3e0 [ 31.646684] do_dentry_open+0x282/0x410 [ 31.651139] vfs_open+0x5d/0xb0 [ 31.654901] path_openat+0x24c/0x1050 [ 31.659181] do_filp_open+0xaa/0x120 [ 31.663374] do_open_execat+0x94/0x1e0 [ 31.667745] do_execveat_common.isra.30+0x311/0xb90 [ 31.673241] SyS_execve+0x39/0x50 [ 31.677182] do_syscall_64+0x7f/0x270 [ 31.681464] return_from_SYSCALL_64+0x0/0x75 [ 31.686351] [ 31.686351] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 31.692645] __mutex_lock+0x6b/0xa00 [ 31.696842] mutex_lock_killable_nested+0x16/0x20 [ 31.702170] lock_trace+0x25/0x70 [ 31.706107] proc_pid_stack+0x64/0xf0 [ 31.710391] proc_single_show+0x55/0x90 [ 31.714851] seq_read+0xf1/0x520 [ 31.718699] __vfs_read+0x43/0x1d0 [ 31.722723] vfs_read+0xce/0x1c0 [ 31.726570] SyS_read+0x57/0xd0 [ 31.730334] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 31.735572] [ 31.735572] -> #0 (&p->lock){+.+.}: [ 31.740641] lock_acquire+0xbf/0x220 [ 31.744835] __mutex_lock+0x6b/0xa00 [ 31.749029] mutex_lock_nested+0x16/0x20 [ 31.753574] seq_read+0x41/0x520 [ 31.757429] proc_reg_read+0x72/0xd0 [ 31.761627] do_iter_read+0x1c3/0x210 [ 31.765912] vfs_readv+0x87/0xc0 [ 31.769763] default_file_splice_read+0x205/0x360 [ 31.775093] do_splice_to+0x95/0xc0 [ 31.779201] SyS_splice+0x762/0x7b0 [ 31.783310] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 31.788544] [ 31.788544] other info that might help us debug this: [ 31.788544] [ 31.796659] Chain exists of: [ 31.796659] &p->lock --> &sig->cred_guard_mutex --> &pipe->mutex/1 [ 31.796659] [ 31.807458] Possible unsafe locking scenario: [ 31.807458] [ 31.813474] CPU0 CPU1 [ 31.818105] ---- ---- [ 31.822733] lock(&pipe->mutex/1); [ 31.826321] lock(&sig->cred_guard_mutex); [ 31.833122] lock(&pipe->mutex/1); [ 31.839227] lock(&p->lock); [ 31.842294] [ 31.842294] *** DEADLOCK *** [ 31.842294] [ 31.848313] 1 lock held by syzkaller687838/4818: [ 31.853028] #0: (&pipe->mutex/1){+.+.}, at: [<00000000deb3c5e2>] pipe_lock+0x29/0x40 [ 31.861048] [ 31.861048] stack backtrace: [ 31.865508] CPU: 1 PID: 4818 Comm: syzkaller687838 Not tainted 4.15.0-rc3-next-20171214+ #67 [ 31.874046] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.883409] Call Trace: [ 31.885968] dump_stack+0xe9/0x14b [ 31.889474] print_circular_bug.isra.38+0x1f3/0x201 [ 31.894450] __lock_acquire+0x1395/0x1430 [ 31.898564] lock_acquire+0xbf/0x220 [ 31.902241] ? lock_acquire+0xbf/0x220 [ 31.906091] ? seq_read+0x41/0x520 [ 31.909591] ? seq_read+0x41/0x520 [ 31.913098] __mutex_lock+0x6b/0xa00 [ 31.916772] ? seq_read+0x41/0x520 [ 31.920275] ? mark_held_locks+0x58/0x80 [ 31.924297] ? __lock_is_held+0x5a/0xa0 [ 31.928234] ? seq_lseek+0x140/0x140 [ 31.931908] mutex_lock_nested+0x16/0x20 [ 31.935929] ? mutex_lock_nested+0x16/0x20 [ 31.940127] seq_read+0x41/0x520 [ 31.943454] ? seq_lseek+0x140/0x140 [ 31.947132] proc_reg_read+0x72/0xd0 [ 31.950822] do_iter_read+0x1c3/0x210 [ 31.954583] vfs_readv+0x87/0xc0 [ 31.957915] ? push_pipe+0x132/0x240 [ 31.961591] ? iov_iter_get_pages_alloc+0x1b0/0x570 [ 31.966573] default_file_splice_read+0x205/0x360 [ 31.971376] ? default_file_splice_read+0x205/0x360 [ 31.976371] ? __might_sleep+0x45/0x80 [ 31.980220] ? fsnotify+0x2de/0x650 [ 31.983813] ? security_file_permission+0x55/0x100 [ 31.988702] ? do_splice_direct+0xe0/0xe0 [ 31.992810] do_splice_to+0x95/0xc0 [ 31.996400] ? do_splice_to+0x95/0xc0 [ 32.000165] SyS_splice+0x762/0x7b0 [ 32.003760] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 32.008481] RIP: 0033:0x44bc19 executing program [ 32.011637] RSP: 002b:00007ff7930abcf8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 [ 32.019307] RAX: ffffffffffffffda RBX: 00007ff7930ac700 RCX: 000000000044bc19 [ 32.026542] RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000006 [ 32.033781] RBP: 00007ffe84e6b1f0 R08: 0000000000000082 R09: 0000000000000000 [ 32.041019] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 [ 32.048251] R13: 00007ffe84e6b1ef R14: 00007ff7930ac9c0 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 program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program