[....] Starting enhanced syslogd: rsyslogd[ 10.642469] audit: type=1400 audit(1514199361.216:5): avc: denied { syslog } for pid=2991 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: [ 16.765755] audit: type=1400 audit(1514199367.339:6): avc: denied { map } for pid=3130 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-5,10.128.0.23' (ECDSA) to the list of known hosts. executing program [ 22.989679] audit: type=1400 audit(1514199373.563:7): avc: denied { map } for pid=3144 comm="syzkaller258281" path="/root/syzkaller258281527" 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 [ 23.063715] [ 23.065350] ====================================================== [ 23.071634] WARNING: possible circular locking dependency detected [ 23.078895] 4.15.0-rc4-mm1+ #49 Not tainted [ 23.083176] ------------------------------------------------------ [ 23.089458] syzkaller258281/3148 is trying to acquire lock: [ 23.095139] (&p->lock){+.+.}, at: [<00000000fca8daf9>] seq_read+0xd5/0x13d0 [ 23.102318] [ 23.102318] but task is already holding lock: [ 23.108256] (&pipe->mutex/1){+.+.}, at: [<0000000005f970d6>] pipe_lock+0x56/0x70 [ 23.115854] [ 23.115854] which lock already depends on the new lock. [ 23.115854] [ 23.124747] [ 23.124747] the existing dependency chain (in reverse order) is: [ 23.132337] [ 23.132337] -> #2 (&pipe->mutex/1){+.+.}: [ 23.137945] __mutex_lock+0x16f/0x1a80 [ 23.142324] mutex_lock_nested+0x16/0x20 [ 23.146883] fifo_open+0x15c/0xa30 [ 23.150915] do_dentry_open+0x667/0xd40 [ 23.155376] vfs_open+0x107/0x220 [ 23.159323] path_openat+0x1151/0x3530 [ 23.163700] do_filp_open+0x25b/0x3b0 [ 23.168859] do_open_execat+0x1b9/0x5c0 [ 23.173324] do_execveat_common.isra.30+0x90c/0x22a0 [ 23.178916] SyS_execve+0x39/0x50 [ 23.182862] do_syscall_64+0x26c/0x920 [ 23.187236] return_from_SYSCALL_64+0x0/0x75 [ 23.192128] [ 23.192128] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 23.198419] __mutex_lock+0x16f/0x1a80 [ 23.202799] mutex_lock_killable_nested+0x16/0x20 [ 23.208130] lock_trace+0x44/0xc0 [ 23.212069] proc_pid_syscall+0xa3/0x550 [ 23.216617] proc_single_show+0xf8/0x170 [ 23.221162] seq_read+0x385/0x13d0 [ 23.225190] do_iter_read+0x3d2/0x5a0 [ 23.229476] vfs_readv+0x121/0x1c0 [ 23.233505] do_readv+0xfc/0x2a0 [ 23.237362] SyS_readv+0x27/0x30 [ 23.241214] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 23.246459] [ 23.246459] -> #0 (&p->lock){+.+.}: [ 23.251533] lock_acquire+0x1d5/0x580 [ 23.255827] __mutex_lock+0x16f/0x1a80 [ 23.260199] mutex_lock_nested+0x16/0x20 [ 23.264744] seq_read+0xd5/0x13d0 [ 23.268688] proc_reg_read+0xe8/0x160 [ 23.272975] do_iter_read+0x3d2/0x5a0 [ 23.277261] vfs_readv+0x121/0x1c0 [ 23.281288] default_file_splice_read+0x508/0xae0 [ 23.286617] do_splice_to+0x10a/0x160 [ 23.290904] SyS_splice+0x1187/0x1610 [ 23.295191] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 23.300428] [ 23.300428] other info that might help us debug this: [ 23.300428] [ 23.308543] Chain exists of: [ 23.308543] &p->lock --> &sig->cred_guard_mutex --> &pipe->mutex/1 [ 23.308543] [ 23.319347] Possible unsafe locking scenario: [ 23.319347] [ 23.325367] CPU0 CPU1 [ 23.329997] ---- ---- [ 23.334632] lock(&pipe->mutex/1); [ 23.338226] lock(&sig->cred_guard_mutex); [ 23.345029] lock(&pipe->mutex/1); [ 23.351138] lock(&p->lock); [ 23.354206] [ 23.354206] *** DEADLOCK *** [ 23.354206] [ 23.360228] 1 lock held by syzkaller258281/3148: [ 23.364944] #0: (&pipe->mutex/1){+.+.}, at: [<0000000005f970d6>] pipe_lock+0x56/0x70 [ 23.372971] [ 23.372971] stack backtrace: [ 23.377435] CPU: 1 PID: 3148 Comm: syzkaller258281 Not tainted 4.15.0-rc4-mm1+ #49 [ 23.385106] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.394427] Call Trace: [ 23.396986] dump_stack+0x194/0x257 [ 23.400581] ? arch_local_irq_restore+0x53/0x53 [ 23.406868] print_circular_bug.isra.37+0x2cd/0x2dc [ 23.411847] ? save_trace+0xe0/0x2b0 [ 23.415524] __lock_acquire+0x30a8/0x3e00 [ 23.419640] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.424798] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.429954] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.435107] ? update_cfs_rq_load_avg.part.68+0x2d0/0x2d0 [ 23.440610] ? print_irqtrace_events+0x270/0x270 [ 23.445328] ? __lock_acquire+0x664/0x3e00 [ 23.449529] ? __lock_acquire+0x664/0x3e00 [ 23.453731] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.458889] ? __lock_acquire+0x664/0x3e00 [ 23.463094] ? print_irqtrace_events+0x270/0x270 [ 23.467813] ? check_noncircular+0x20/0x20 [ 23.472015] ? check_noncircular+0x20/0x20 [ 23.476224] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.481379] ? check_noncircular+0x20/0x20 [ 23.485577] ? __update_idle_core+0x305/0x600 [ 23.490042] ? __lock_acquire+0x664/0x3e00 [ 23.494659] lock_acquire+0x1d5/0x580 [ 23.498427] ? lock_acquire+0x1d5/0x580 [ 23.502368] ? seq_read+0xd5/0x13d0 [ 23.505963] ? lock_release+0xa40/0xa40 [ 23.509905] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.515765] ? rcu_note_context_switch+0x710/0x710 [ 23.520668] ? __might_sleep+0x95/0x190 [ 23.524607] ? seq_read+0xd5/0x13d0 [ 23.528198] __mutex_lock+0x16f/0x1a80 [ 23.532051] ? seq_read+0xd5/0x13d0 [ 23.535645] ? __is_insn_slot_addr+0x1fc/0x330 [ 23.540200] ? seq_read+0xd5/0x13d0 [ 23.543803] ? check_noncircular+0x20/0x20 [ 23.548006] ? mutex_lock_io_nested+0x1900/0x1900 [ 23.552817] ? find_held_lock+0x35/0x1d0 [ 23.556842] ? check_noncircular+0x20/0x20 [ 23.561043] ? is_bpf_text_address+0x7b/0x120 [ 23.565502] ? check_noncircular+0x20/0x20 [ 23.569701] ? print_irqtrace_events+0x270/0x270 [ 23.574423] ? check_noncircular+0x20/0x20 [ 23.578621] ? find_held_lock+0x35/0x1d0 [ 23.582648] ? __lock_is_held+0xb6/0x140 [ 23.586674] ? check_noncircular+0x20/0x20 [ 23.590877] ? __lock_is_held+0xb6/0x140 [ 23.594908] ? rcu_read_lock_sched_held+0x108/0x120 [ 23.599888] ? __lock_is_held+0xb6/0x140 [ 23.603914] ? seq_lseek+0x3c0/0x3c0 [ 23.607592] mutex_lock_nested+0x16/0x20 [ 23.611640] ? mutex_lock_nested+0x16/0x20 [ 23.616109] seq_read+0xd5/0x13d0 [ 23.619533] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.625382] ? __check_object_size+0x25d/0x4f0 [ 23.629942] ? fsnotify+0x7b3/0x1140 [ 23.633625] ? seq_lseek+0x3c0/0x3c0 [ 23.637303] ? fsnotify_first_mark+0x2b0/0x2b0 [ 23.641854] ? avc_policy_seqno+0x9/0x20 [ 23.645886] ? selinux_file_permission+0x82/0x460 [ 23.651128] ? seq_lseek+0x3c0/0x3c0 [ 23.654813] proc_reg_read+0xe8/0x160 [ 23.658583] ? rw_verify_area+0xe5/0x2b0 [ 23.662618] do_iter_read+0x3d2/0x5a0 [ 23.666386] ? dup_iter+0x260/0x260 [ 23.669978] vfs_readv+0x121/0x1c0 [ 23.673484] ? compat_rw_copy_check_uvector+0x2e0/0x2e0 [ 23.678990] ? lock_acquire+0x1d5/0x580 [ 23.682934] ? lock_acquire+0x1d5/0x580 [ 23.686872] ? pipe_lock+0x56/0x70 [ 23.690377] ? lock_release+0xa40/0xa40 [ 23.694316] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.700175] ? rcu_note_context_switch+0x710/0x710 [ 23.705078] ? __might_sleep+0x95/0x190 [ 23.709029] ? pipe_lock+0x56/0x70 [ 23.712557] ? __mutex_lock+0x16f/0x1a80 [ 23.716585] ? pipe_lock+0x56/0x70 [ 23.720102] default_file_splice_read+0x508/0xae0 [ 23.724910] ? default_file_splice_read+0x508/0xae0 [ 23.729900] ? do_splice_direct+0x3c0/0x3c0 [ 23.734189] ? __lock_is_held+0xb6/0x140 [ 23.738310] ? __lock_is_held+0xb6/0x140 [ 23.742338] ? fsnotify+0x7b3/0x1140 [ 23.746027] ? fsnotify_first_mark+0x2b0/0x2b0 [ 23.750581] ? avc_policy_seqno+0x9/0x20 [ 23.754610] ? selinux_file_permission+0x82/0x460 [ 23.759417] ? security_file_permission+0x89/0x1e0 [ 23.764317] ? do_splice_direct+0x3c0/0x3c0 [ 23.768605] do_splice_to+0x10a/0x160 [ 23.772370] ? do_splice_to+0x10a/0x160 [ 23.776310] SyS_splice+0x1187/0x1610 [ 23.780075] ? SyS_futex+0x269/0x390 [ 23.783756] ? compat_SyS_vmsplice+0x250/0x250 [ 23.788303] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 23.793290] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 23.798017] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 23.802746] RIP: 0033:0x445679 [ 23.805902] RSP: 002b:00007fa003d58d08 EFLAGS: 00000216 ORIG_RAX: 0000000000000113 [ 23.813574] RAX: ffffffffffffffda RBX: 0