[....] Starting enhanced syslogd: rsyslogd[ 12.723445] audit: type=1400 audit(1513702099.687:5): avc: denied { syslog } for pid=2998 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 OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.874708] audit: type=1400 audit(1513702105.838:6): avc: denied { map } for pid=3138 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-3,10.128.0.32' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program [ 27.982800] audit: type=1400 audit(1513702114.946:7): avc: denied { map } for pid=3153 comm="syzkaller406451" path="/root/syzkaller406451447" 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 [ 28.046000] [ 28.047655] ====================================================== [ 28.053935] WARNING: possible circular locking dependency detected [ 28.060217] 4.15.0-rc2-mm1+ #39 Not tainted [ 28.064501] ------------------------------------------------------ [ 28.070783] syzkaller406451/3206 is trying to acquire lock: [ 28.076456] (&p->lock){+.+.}, at: [<00000000345e6443>] seq_read+0xd5/0x13d0 [ 28.083620] [ 28.083620] but task is already holding lock: executing program executing program [ 28.089570] (&pipe->mutex/1){+.+.}, at: [<00000000112c390a>] pipe_lock+0x56/0x70 [ 28.097163] [ 28.097163] which lock already depends on the new lock. [ 28.097163] [ 28.105453] [ 28.105453] the existing dependency chain (in reverse order) is: [ 28.113037] [ 28.113037] -> #2 (&pipe->mutex/1){+.+.}: [ 28.118637] lock_acquire+0x1d5/0x580 [ 28.122923] __mutex_lock+0x16f/0x1a80 [ 28.127296] mutex_lock_nested+0x16/0x20 [ 28.131841] fifo_open+0x15c/0xa40 [ 28.135869] do_dentry_open+0x682/0xd70 [ 28.140341] vfs_open+0x107/0x230 [ 28.144280] path_openat+0x1157/0x3530 [ 28.148653] do_filp_open+0x25b/0x3b0 [ 28.152942] do_open_execat+0x1b9/0x5c0 [ 28.157399] do_execveat_common.isra.30+0x90c/0x22a0 [ 28.162986] SyS_execve+0x39/0x50 [ 28.166926] do_syscall_64+0x26c/0x920 [ 28.171302] return_from_SYSCALL_64+0x0/0x75 [ 28.176192] [ 28.176192] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 28.182481] lock_acquire+0x1d5/0x580 [ 28.186766] __mutex_lock+0x16f/0x1a80 [ 28.191139] mutex_lock_killable_nested+0x16/0x20 [ 28.196475] lock_trace+0x44/0xc0 [ 28.200413] proc_pid_stack+0x170/0x340 [ 28.204871] proc_single_show+0xf8/0x170 [ 28.209419] seq_read+0x385/0x13d0 [ 28.213461] __vfs_read+0xef/0xa00 [ 28.217483] vfs_read+0x124/0x360 [ 28.221424] SyS_read+0xef/0x220 [ 28.225275] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 28.230511] [ 28.230511] -> #0 (&p->lock){+.+.}: [ 28.235588] __lock_acquire+0x3498/0x47f0 [ 28.240221] lock_acquire+0x1d5/0x580 [ 28.244504] __mutex_lock+0x16f/0x1a80 [ 28.248876] mutex_lock_nested+0x16/0x20 [ 28.253420] seq_read+0xd5/0x13d0 [ 28.257357] proc_reg_read+0xef/0x170 [ 28.261641] do_iter_read+0x3db/0x5b0 [ 28.265926] vfs_readv+0x121/0x1c0 [ 28.269953] default_file_splice_read+0x508/0xae0 [ 28.275278] do_splice_to+0x110/0x170 [ 28.279563] SyS_splice+0x11a8/0x1630 [ 28.283848] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 28.289087] [ 28.289087] other info that might help us debug this: [ 28.289087] [ 28.297191] Chain exists of: [ 28.297191] &p->lock --> &sig->cred_guard_mutex --> &pipe->mutex/1 [ 28.297191] [ 28.307995] Possible unsafe locking scenario: [ 28.307995] [ 28.314028] CPU0 CPU1 [ 28.318663] ---- ---- [ 28.323292] lock(&pipe->mutex/1); [ 28.326885] lock(&sig->cred_guard_mutex); [ 28.333685] lock(&pipe->mutex/1); [ 28.339792] lock(&p->lock); [ 28.342862] [ 28.342862] *** DEADLOCK *** [ 28.342862] [ 28.348884] 1 lock held by syzkaller406451/3206: [ 28.353599] #0: (&pipe->mutex/1){+.+.}, at: [<00000000112c390a>] pipe_lock+0x56/0x70 [ 28.361626] [ 28.361626] stack backtrace: [ 28.366088] CPU: 0 PID: 3206 Comm: syzkaller406451 Not tainted 4.15.0-rc2-mm1+ #39 [ 28.373757] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.383074] Call Trace: [ 28.385630] dump_stack+0x194/0x257 [ 28.389224] ? arch_local_irq_restore+0x53/0x53 [ 28.393861] print_circular_bug+0x42d/0x610 [ 28.398148] ? save_stack_trace+0x1a/0x20 [ 28.402271] check_prev_add+0x666/0x15f0 [ 28.406297] ? check_usage+0x22f/0xb60 [ 28.410147] ? copy_trace+0x150/0x150 [ 28.413912] ? check_usage+0xb60/0xb60 [ 28.417767] __lock_acquire+0x3498/0x47f0 [ 28.421888] ? __lock_acquire+0x3498/0x47f0 [ 28.426178] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 28.431330] ? do_splice_to+0x110/0x170 [ 28.435270] ? unwind_next_frame.part.6+0x1a6/0xb40 [ 28.440251] ? unwind_dump+0x4d0/0x4d0 [ 28.444104] ? unwind_next_frame.part.6+0x1a6/0xb40 [ 28.449086] ? unwind_next_frame.part.6+0x1a6/0xb40 [ 28.454065] ? unwind_dump+0x4d0/0x4d0 [ 28.457915] ? unwind_dump+0x4d0/0x4d0 [ 28.461768] ? __kernel_text_address+0xd/0x40 [ 28.466226] ? unwind_get_return_address+0x61/0xa0 [ 28.471120] ? check_noncircular+0x20/0x20 [ 28.475317] ? __kernel_text_address+0xd/0x40 [ 28.479777] ? unwind_get_return_address+0x61/0xa0 [ 28.484671] ? do_splice_to+0x110/0x170 [ 28.488609] ? save_stack_trace+0x1a/0x20 [ 28.492723] lock_acquire+0x1d5/0x580 [ 28.496487] ? seq_read+0xd5/0x13d0 [ 28.500078] ? lock_release+0xda0/0xda0 [ 28.504019] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 28.509871] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 28.515027] ? rcu_note_context_switch+0x710/0x710 [ 28.519920] ? __might_sleep+0x95/0x190 [ 28.523859] ? seq_read+0xd5/0x13d0 [ 28.527450] __mutex_lock+0x16f/0x1a80 [ 28.531303] ? seq_read+0xd5/0x13d0 [ 28.534893] ? check_noncircular+0x20/0x20 [ 28.539095] ? __free_insn_slot+0x5c0/0x5c0 [ 28.543379] ? seq_read+0xd5/0x13d0 [ 28.546969] ? find_held_lock+0x39/0x1d0 [ 28.550994] ? mutex_lock_io_nested+0x1900/0x1900 [ 28.555801] ? check_noncircular+0x20/0x20 [ 28.560002] ? check_noncircular+0x20/0x20 [ 28.564202] ? print_usage_bug+0x3f0/0x3f0 [ 28.568399] ? find_held_lock+0x39/0x1d0 [ 28.572426] ? check_noncircular+0x20/0x20 [ 28.576624] ? __lock_is_held+0xbc/0x140 [ 28.580651] ? check_noncircular+0x20/0x20 [ 28.584848] ? __lock_is_held+0xbc/0x140 [ 28.588878] ? rcu_read_lock_sched_held+0x108/0x120 [ 28.593859] ? __lock_is_held+0xbc/0x140 [ 28.597885] ? seq_lseek+0x3c0/0x3c0 [ 28.601564] mutex_lock_nested+0x16/0x20 [ 28.605597] ? mutex_lock_nested+0x16/0x20 [ 28.609796] seq_read+0xd5/0x13d0 [ 28.613228] ? fsnotify+0x7b3/0x1140 [ 28.616909] ? seq_lseek+0x3c0/0x3c0 [ 28.620589] ? fsnotify_first_mark+0x2b0/0x2b0 [ 28.625137] ? avc_policy_seqno+0x9/0x20 [ 28.629174] ? selinux_file_permission+0x82/0x460 [ 28.633983] ? seq_lseek+0x3c0/0x3c0 [ 28.637661] proc_reg_read+0xef/0x170 [ 28.641432] do_iter_read+0x3db/0x5b0 [ 28.645204] ? dup_iter+0x260/0x260 [ 28.648802] vfs_readv+0x121/0x1c0 [ 28.652310] ? compat_rw_copy_check_uvector+0x2e0/0x2e0 [ 28.657648] ? lock_acquire+0x1d5/0x580 [ 28.661591] ? pipe_lock+0x56/0x70 [ 28.665099] ? lock_release+0xda0/0xda0 [ 28.669043] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 28.674895] ? rcu_note_context_switch+0x710/0x710 [ 28.679792] ? __might_sleep+0x95/0x190 [ 28.683732] ? pipe_lock+0x56/0x70 [ 28.687237] ? __mutex_lock+0x16f/0x1a80 [ 28.691262] ? pipe_lock+0x56/0x70 [ 28.694771] default_file_splice_read+0x508/0xae0 [ 28.699580] ? default_file_splice_read+0x508/0xae0 [ 28.704569] ? do_splice_direct+0x3d0/0x3d0 [ 28.708858] ? __lock_is_held+0xbc/0x140 [ 28.712889] ? __lock_is_held+0xbc/0x140 [ 28.716922] ? fsnotify+0x7b3/0x1140 [ 28.720604] ? fsnotify_first_mark+0x2b0/0x2b0 [ 28.725153] ? avc_policy_seqno+0x9/0x20 [ 28.729180] ? selinux_file_permission+0x82/0x460 [ 28.734018] ? security_file_permission+0x89/0x1f0 [ 28.738914] ? do_splice_direct+0x3d0/0x3d0 [ 28.743199] do_splice_to+0x110/0x170 [ 28.746963] ? do_splice_to+0x110/0x170 [ 28.750904] SyS_splice+0x11a8/0x1630 [ 28.754680] ? lockdep_sys_exit+0x47/0xf0 [ 28.758795] ? compat_SyS_vmsplice+0x250/0x250 [ 28.763341] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 28.768325] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 28.773050] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 28.777769] RIP: 0033:0x4459c9 [ 28.780925] RSP: 002b:00007fecd1130d28 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 [ 28.788598] RAX: ffffffffffffffda RBX: 00007fecd1131700 RCX: 00000000004459c9 executing program executing program executing program [ 28.795832] RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000005 [ 28.803068] RBP: 00007ffdb8ee6180 R08: 0000000000000082 R09: 0000000000000000 [ 28.810304] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 [ 28.817538] R13: 00007ffdb8ee617f R14: 00007fecd11319c0 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