[ 12.066536] audit: type=1400 audit(1512852283.843:5): avc: denied { syslog } for pid=2997 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [....] Starting enhanced syslogd: rsyslogd[?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: [ 20.481968] audit: type=1400 audit(1512852292.258:6): avc: denied { map } for pid=3140 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-mmots-kasan-gce-5,10.128.15.223' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 26.777452] audit: type=1400 audit(1512852298.554:7): avc: denied { map } for pid=3154 comm="syzkaller408042" path="/root/syzkaller408042539" 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 [ 26.904406] [ 26.906037] ====================================================== [ 26.912314] WARNING: possible circular locking dependency detected [ 26.918594] 4.15.0-rc2-mm1+ #39 Not tainted [ 26.922879] ------------------------------------------------------ [ 26.929157] syzkaller408042/3177 is trying to acquire lock: [ 26.934827] (&sig->cred_guard_mutex){+.+.}, at: [<00000000d8b74695>] lock_trace+0x44/0xc0 [ 26.943199] [ 26.943199] but task is already holding lock: executing program [ 26.949129] (&p->lock){+.+.}, at: [<00000000453b9d10>] seq_read+0xd5/0x13d0 [ 26.956285] [ 26.956285] which lock already depends on the new lock. [ 26.956285] [ 26.964559] [ 26.964559] the existing dependency chain (in reverse order) is: [ 26.972145] [ 26.972145] -> #2 (&p->lock){+.+.}: [ 26.977216] lock_acquire+0x1d5/0x580 [ 26.981502] __mutex_lock+0x16f/0x1a80 [ 26.985871] mutex_lock_nested+0x16/0x20 [ 26.990413] seq_read+0xd5/0x13d0 [ 26.994348] do_iter_read+0x3db/0x5b0 [ 26.998640] vfs_readv+0x121/0x1c0 [ 27.002672] default_file_splice_read+0x508/0xae0 [ 27.008000] do_splice_to+0x110/0x170 [ 27.012292] SyS_splice+0x11a8/0x1630 [ 27.016579] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 27.021818] [ 27.021818] -> #1 (&pipe->mutex/1){+.+.}: [ 27.027418] lock_acquire+0x1d5/0x580 [ 27.031704] __mutex_lock+0x16f/0x1a80 [ 27.036078] mutex_lock_nested+0x16/0x20 [ 27.040623] fifo_open+0x15c/0xa40 [ 27.044650] do_dentry_open+0x682/0xd70 [ 27.049112] vfs_open+0x107/0x230 [ 27.053049] path_openat+0x1157/0x3530 [ 27.057421] do_filp_open+0x25b/0x3b0 [ 27.061707] do_open_execat+0x1b9/0x5c0 [ 27.066166] do_execveat_common.isra.30+0x90c/0x22a0 [ 27.071752] SyS_execve+0x39/0x50 [ 27.075690] do_syscall_64+0x26c/0x920 [ 27.080062] return_from_SYSCALL_64+0x0/0x75 [ 27.084951] [ 27.084951] -> #0 (&sig->cred_guard_mutex){+.+.}: [ 27.091241] __lock_acquire+0x3498/0x47f0 [ 27.095878] lock_acquire+0x1d5/0x580 [ 27.100163] __mutex_lock+0x16f/0x1a80 [ 27.104536] mutex_lock_killable_nested+0x16/0x20 [ 27.109864] lock_trace+0x44/0xc0 [ 27.113801] proc_pid_syscall+0xa3/0x550 [ 27.118346] proc_single_show+0xf8/0x170 [ 27.122893] seq_read+0x385/0x13d0 [ 27.126919] do_iter_read+0x3db/0x5b0 [ 27.131206] vfs_readv+0x121/0x1c0 [ 27.135235] default_file_splice_read+0x508/0xae0 [ 27.140561] do_splice_to+0x110/0x170 [ 27.144849] SyS_splice+0x11a8/0x1630 [ 27.149134] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 27.154373] [ 27.154373] other info that might help us debug this: [ 27.154373] [ 27.162477] Chain exists of: [ 27.162477] &sig->cred_guard_mutex --> &pipe->mutex/1 --> &p->lock [ 27.162477] [ 27.173285] Possible unsafe locking scenario: [ 27.173285] [ 27.179304] CPU0 CPU1 [ 27.183933] ---- ---- [ 27.188562] lock(&p->lock); [ 27.191631] lock(&pipe->mutex/1); [ 27.197741] lock(&p->lock); [ 27.203329] lock(&sig->cred_guard_mutex); [ 27.207613] [ 27.207613] *** DEADLOCK *** [ 27.207613] [ 27.213635] 2 locks held by syzkaller408042/3177: [ 27.218440] #0: (&pipe->mutex/1){+.+.}, at: [<00000000989db40a>] pipe_lock+0x56/0x70 [ 27.226470] #1: (&p->lock){+.+.}, at: [<00000000453b9d10>] seq_read+0xd5/0x13d0 [ 27.234061] [ 27.234061] stack backtrace: [ 27.238522] CPU: 1 PID: 3177 Comm: syzkaller408042 Not tainted 4.15.0-rc2-mm1+ #39 [ 27.246193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.255514] Call Trace: [ 27.258072] dump_stack+0x194/0x257 [ 27.261664] ? arch_local_irq_restore+0x53/0x53 [ 27.266303] print_circular_bug+0x42d/0x610 [ 27.270590] ? save_stack_trace+0x1a/0x20 [ 27.274702] check_prev_add+0x666/0x15f0 [ 27.278729] ? lock_release+0xda0/0xda0 [ 27.282668] ? copy_trace+0x150/0x150 [ 27.286434] ? check_usage+0xb60/0xb60 [ 27.290287] ? check_usage_forwards+0x410/0x410 [ 27.294932] __lock_acquire+0x3498/0x47f0 [ 27.299045] ? __lock_acquire+0x3498/0x47f0 [ 27.303335] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 27.308494] ? unwind_next_frame.part.6+0x1a6/0xb40 [ 27.313475] ? unwind_next_frame.part.6+0x1a6/0xb40 [ 27.318454] ? unwind_dump+0x4d0/0x4d0 [ 27.322307] ? unwind_dump+0x4d0/0x4d0 [ 27.326161] ? unwind_get_return_address+0x61/0xa0 [ 27.331059] ? __unwind_start+0x169/0x330 [ 27.335173] ? unwind_get_return_address+0x61/0xa0 [ 27.340068] ? __save_stack_trace+0x61/0xd0 [ 27.344354] ? check_noncircular+0x20/0x20 [ 27.348555] ? seq_read+0x7cd/0x13d0 [ 27.352234] ? __lock_acquire+0x324e/0x47f0 [ 27.356521] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 27.361676] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 27.366834] lock_acquire+0x1d5/0x580 [ 27.370601] ? lock_trace+0x44/0xc0 [ 27.374195] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 27.379352] ? lock_release+0xda0/0xda0 [ 27.383293] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 27.389144] ? rcu_note_context_switch+0x710/0x710 [ 27.394038] ? __might_sleep+0x95/0x190 [ 27.397977] ? lock_trace+0x44/0xc0 [ 27.401568] __mutex_lock+0x16f/0x1a80 [ 27.405422] ? lock_trace+0x44/0xc0 [ 27.409017] ? lock_trace+0x44/0xc0 [ 27.412611] ? __free_insn_slot+0x5c0/0x5c0 [ 27.416899] ? mutex_lock_io_nested+0x1900/0x1900 [ 27.421711] ? __lock_acquire+0x6e9/0x47f0 [ 27.425912] ? find_held_lock+0x39/0x1d0 [ 27.429945] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 27.435099] ? rcutorture_record_progress+0x10/0x10 [ 27.440082] ? lock_release+0xda0/0xda0 [ 27.444022] ? is_bpf_text_address+0xa4/0x120 [ 27.448485] ? mark_held_locks+0xb2/0x100 [ 27.452601] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 27.457672] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 27.462652] ? trace_hardirqs_on+0xd/0x10 [ 27.466765] ? check_noncircular+0x20/0x20 [ 27.470966] ? depot_save_stack+0x2ca/0x460 [ 27.475255] ? save_stack+0xa3/0xd0 [ 27.478847] ? save_stack+0x43/0xd0 [ 27.482440] ? kasan_kmalloc+0xad/0xe0 [ 27.486292] ? __kmalloc_node+0x47/0x70 [ 27.490234] ? check_noncircular+0x20/0x20 [ 27.494434] ? vfs_readv+0x121/0x1c0 [ 27.498112] ? default_file_splice_read+0x508/0xae0 [ 27.503093] mutex_lock_killable_nested+0x16/0x20 [ 27.507903] ? mutex_lock_killable_nested+0x16/0x20 [ 27.512883] lock_trace+0x44/0xc0 [ 27.516302] proc_pid_syscall+0xa3/0x550 [ 27.520331] ? proc_pid_stack+0x340/0x340 [ 27.524442] ? __lock_is_held+0xbc/0x140 [ 27.528475] ? rcu_read_lock_held+0xa9/0xc0 [ 27.532761] ? pid_task+0xf7/0x1a0 [ 27.536270] ? kasan_kmalloc+0xad/0xe0 [ 27.540124] proc_single_show+0xf8/0x170 [ 27.544151] seq_read+0x385/0x13d0 [ 27.547659] ? seq_lseek+0x3c0/0x3c0 [ 27.551339] ? selinux_file_permission+0x82/0x460 [ 27.556150] ? security_file_permission+0x89/0x1f0 [ 27.561044] ? rw_verify_area+0xe5/0x2b0 [ 27.565072] do_iter_read+0x3db/0x5b0 [ 27.568841] ? dup_iter+0x260/0x260 [ 27.572433] vfs_readv+0x121/0x1c0 [ 27.575939] ? compat_rw_copy_check_uvector+0x2e0/0x2e0 [ 27.581270] ? lock_acquire+0x1d5/0x580 [ 27.585207] ? pipe_lock+0x56/0x70 [ 27.588712] ? lock_release+0xda0/0xda0 [ 27.592654] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 27.598505] ? rcu_note_context_switch+0x710/0x710 [ 27.603401] ? __might_sleep+0x95/0x190 [ 27.607340] ? pipe_lock+0x56/0x70 [ 27.610844] ? __mutex_lock+0x16f/0x1a80 [ 27.614869] ? pipe_lock+0x56/0x70 [ 27.618374] default_file_splice_read+0x508/0xae0 [ 27.623181] ? default_file_splice_read+0x508/0xae0 [ 27.628164] ? do_splice_direct+0x3d0/0x3d0 [ 27.632449] ? __lock_is_held+0xbc/0x140 [ 27.636480] ? __lock_is_held+0xbc/0x140 [ 27.640511] ? fsnotify+0x7b3/0x1140 [ 27.644196] ? security_file_permission+0x89/0x1f0 [ 27.649093] ? do_splice_direct+0x3d0/0x3d0 [ 27.653380] do_splice_to+0x110/0x170 [ 27.657146] ? do_splice_to+0x110/0x170 [ 27.661086] SyS_splice+0x11a8/0x1630 [ 27.664852] ? lockdep_sys_exit+0x47/0xf0 [ 27.668968] ? compat_SyS_vmsplice+0x250/0x250 [ 27.673516] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 27.678497] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 27.683221] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 27.687940] RIP: 0033:0x44a559 [ 27.691094] RSP: 002b:00007fc37ca0bd28 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 [ 27.698769] RAX: ffffffffffffffda RBX: 00007fc37ca0c700 RCX: 000000000044a559 executing program [ 27.706004] RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000006 [ 27.713241] RBP: 00007ffdb54a6600 R08: 000000000000a3ea R09: 0000000000000000 [ 27.720476] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 [ 27.727710] R13: 00007ffdb54a65ff R14: 00007fc37ca0c9c0 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