[....] Starting enhanced syslogd: rsyslogd[ 11.126140] audit: type=1400 audit(1514146629.494:5): 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 17.082157] audit: type=1400 audit(1514146635.449:6): avc: denied { map } for pid=3137 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-kasan-gce-9,10.128.0.24' (ECDSA) to the list of known hosts. [ 23.379328] audit: type=1400 audit(1514146641.747:7): avc: denied { map } for pid=3151 comm="syzkaller128024" path="/root/syzkaller128024767" 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 [ 23.405347] audit: type=1400 audit(1514146641.747:8): avc: denied { sys_admin } for pid=3151 comm="syzkaller128024" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 executing program [ 23.492419] audit: type=1400 audit(1514146641.860:9): avc: denied { sys_chroot } for pid=3152 comm="syzkaller128024" capability=18 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 [ 23.517050] audit: type=1400 audit(1514146641.884:10): avc: denied { dac_override } for pid=3152 comm="syzkaller128024" capability=1 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 [ 23.542946] [ 23.544570] ====================================================== [ 23.550862] WARNING: possible circular locking dependency detected [ 23.557154] 4.15.0-rc5+ #237 Not tainted [ 23.561177] ------------------------------------------------------ [ 23.567465] syzkaller128024/3156 is trying to acquire lock: [ 23.573139] (&p->lock){+.+.}, at: [<00000000d799377f>] seq_read+0xd5/0x13d0 [ 23.580309] [ 23.580309] but task is already holding lock: [ 23.586253] (&pipe->mutex/1){+.+.}, at: [<00000000c4279ecd>] pipe_lock+0x56/0x70 [ 23.593848] [ 23.593848] which lock already depends on the new lock. [ 23.593848] [ 23.602127] [ 23.602127] the existing dependency chain (in reverse order) is: [ 23.609718] [ 23.609718] -> #2 (&pipe->mutex/1){+.+.}: [ 23.615326] __mutex_lock+0x16f/0x1a80 [ 23.619700] mutex_lock_nested+0x16/0x20 [ 23.624249] fifo_open+0x15c/0xa30 [ 23.628276] do_dentry_open+0x667/0xd40 [ 23.632740] vfs_open+0x107/0x220 [ 23.636679] path_openat+0x1151/0x3530 [ 23.641049] do_filp_open+0x25b/0x3b0 [ 23.645335] do_open_execat+0x1b9/0x5c0 [ 23.649793] do_execveat_common.isra.30+0x90c/0x23c0 [ 23.655379] SyS_execve+0x39/0x50 [ 23.659317] do_syscall_64+0x26c/0x920 [ 23.664095] return_from_SYSCALL_64+0x0/0x75 [ 23.668993] [ 23.668993] -> #1 (&sig->cred_guard_mutex){+.+.}: [ 23.675288] __mutex_lock+0x16f/0x1a80 [ 23.679659] mutex_lock_killable_nested+0x16/0x20 [ 23.684985] lock_trace+0x44/0xc0 [ 23.688929] proc_pid_syscall+0xa3/0x550 [ 23.693479] proc_single_show+0xf8/0x170 [ 23.698034] seq_read+0x385/0x13d0 [ 23.702065] do_iter_read+0x3d2/0x5a0 [ 23.706351] vfs_readv+0x121/0x1c0 [ 23.710375] do_readv+0xfc/0x2a0 [ 23.714223] SyS_readv+0x27/0x30 [ 23.718074] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 23.723310] [ 23.723310] -> #0 (&p->lock){+.+.}: [ 23.728388] lock_acquire+0x1d5/0x580 [ 23.732676] __mutex_lock+0x16f/0x1a80 [ 23.737046] mutex_lock_nested+0x16/0x20 [ 23.741591] seq_read+0xd5/0x13d0 [ 23.745529] proc_reg_read+0xef/0x170 [ 23.749811] do_iter_read+0x3d2/0x5a0 [ 23.754094] vfs_readv+0x121/0x1c0 [ 23.758119] default_file_splice_read+0x508/0xae0 [ 23.763446] do_splice_to+0x10a/0x160 [ 23.767730] SyS_splice+0x1187/0x1610 [ 23.772021] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 23.777259] [ 23.777259] other info that might help us debug this: [ 23.777259] [ 23.785363] Chain exists of: [ 23.785363] &p->lock --> &sig->cred_guard_mutex --> &pipe->mutex/1 [ 23.785363] [ 23.796165] Possible unsafe locking scenario: [ 23.796165] [ 23.802185] CPU0 CPU1 [ 23.806814] ---- ---- [ 23.811441] lock(&pipe->mutex/1); [ 23.815034] lock(&sig->cred_guard_mutex); [ 23.821834] lock(&pipe->mutex/1); [ 23.827942] lock(&p->lock); [ 23.831015] [ 23.831015] *** DEADLOCK *** [ 23.831015] [ 23.837043] 1 lock held by syzkaller128024/3156: [ 23.841762] #0: (&pipe->mutex/1){+.+.}, at: [<00000000c4279ecd>] pipe_lock+0x56/0x70 [ 23.849790] [ 23.849790] stack backtrace: [ 23.854252] CPU: 1 PID: 3156 Comm: syzkaller128024 Not tainted 4.15.0-rc5+ #237 [ 23.861665] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.870989] Call Trace: [ 23.873544] dump_stack+0x194/0x257 [ 23.877136] ? arch_local_irq_restore+0x53/0x53 [ 23.881773] print_circular_bug.isra.37+0x2cd/0x2dc [ 23.886753] ? save_trace+0xe0/0x2b0 [ 23.890431] __lock_acquire+0x30a8/0x3e00 [ 23.894541] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.899696] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.904849] ? lockdep_on+0x50/0x50 [ 23.908439] ? trace_hardirqs_off+0x10/0x10 [ 23.912724] ? print_irqtrace_events+0x270/0x270 [ 23.917443] ? __lock_acquire+0x664/0x3e00 [ 23.921641] ? __lock_acquire+0x664/0x3e00 [ 23.925841] ? print_irqtrace_events+0x270/0x270 [ 23.930571] ? __lock_acquire+0x664/0x3e00 [ 23.934779] ? print_irqtrace_events+0x270/0x270 [ 23.939500] ? check_noncircular+0x20/0x20 [ 23.943699] ? __lock_acquire+0x664/0x3e00 [ 23.947897] ? check_noncircular+0x20/0x20 [ 23.952095] ? __update_idle_core+0x305/0x600 [ 23.956555] ? __lock_acquire+0x664/0x3e00 [ 23.960760] lock_acquire+0x1d5/0x580 [ 23.964531] ? lock_acquire+0x1d5/0x580 [ 23.968476] ? seq_read+0xd5/0x13d0 [ 23.972068] ? lock_release+0xa40/0xa40 [ 23.976010] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.981865] ? rcu_note_context_switch+0x710/0x710 [ 23.986760] ? __might_sleep+0x95/0x190 [ 23.990700] ? seq_read+0xd5/0x13d0 [ 23.994297] __mutex_lock+0x16f/0x1a80 [ 23.998154] ? seq_read+0xd5/0x13d0 [ 24.001748] ? __is_insn_slot_addr+0x1fc/0x330 [ 24.006294] ? seq_read+0xd5/0x13d0 [ 24.009886] ? mutex_lock_io_nested+0x1900/0x1900 [ 24.014694] ? find_held_lock+0x35/0x1d0 [ 24.018721] ? check_noncircular+0x20/0x20 [ 24.022928] ? is_bpf_text_address+0x7b/0x120 [ 24.027393] ? check_noncircular+0x20/0x20 [ 24.031599] ? print_irqtrace_events+0x270/0x270 [ 24.036322] ? depot_save_stack+0x3b5/0x490 [ 24.040609] ? check_noncircular+0x20/0x20 [ 24.044811] ? find_held_lock+0x35/0x1d0 [ 24.048838] ? __lock_is_held+0xb6/0x140 [ 24.052864] ? check_noncircular+0x20/0x20 [ 24.057061] ? __lock_is_held+0xb6/0x140 [ 24.061088] ? rcu_read_lock_sched_held+0x108/0x120 [ 24.066068] ? __lock_is_held+0xb6/0x140 [ 24.070094] ? seq_lseek+0x3c0/0x3c0 [ 24.073772] mutex_lock_nested+0x16/0x20 [ 24.077795] ? mutex_lock_nested+0x16/0x20 [ 24.081998] seq_read+0xd5/0x13d0 [ 24.085427] ? fsnotify+0x7b3/0x1140 [ 24.089106] ? seq_lseek+0x3c0/0x3c0 [ 24.092789] ? fsnotify_first_mark+0x2b0/0x2b0 [ 24.097340] ? avc_policy_seqno+0x9/0x20 [ 24.101365] ? selinux_file_permission+0x82/0x460 [ 24.106172] ? seq_lseek+0x3c0/0x3c0 [ 24.110551] proc_reg_read+0xef/0x170 [ 24.114320] do_iter_read+0x3d2/0x5a0 [ 24.118087] ? dup_iter+0x260/0x260 [ 24.121682] vfs_readv+0x121/0x1c0 [ 24.125194] ? compat_rw_copy_check_uvector+0x2e0/0x2e0 [ 24.130524] ? lock_acquire+0x1d5/0x580 [ 24.134463] ? lock_acquire+0x1d5/0x580 [ 24.138400] ? pipe_lock+0x56/0x70 [ 24.141911] ? lock_release+0xa40/0xa40 [ 24.145860] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 24.151711] ? rcu_note_context_switch+0x710/0x710 [ 24.156617] ? __might_sleep+0x95/0x190 [ 24.160570] ? pipe_lock+0x56/0x70 [ 24.164086] ? __mutex_lock+0x16f/0x1a80 [ 24.168117] ? pipe_lock+0x56/0x70 [ 24.171638] default_file_splice_read+0x508/0xae0 [ 24.176467] ? default_file_splice_read+0x508/0xae0 [ 24.181473] ? do_splice_direct+0x3c0/0x3c0 [ 24.185778] ? __lock_is_held+0xb6/0x140 [ 24.189821] ? __lock_is_held+0xb6/0x140 [ 24.193854] ? fsnotify+0x7b3/0x1140 [ 24.197534] ? fsnotify_first_mark+0x2b0/0x2b0 [ 24.202084] ? avc_policy_seqno+0x9/0x20 [ 24.206112] ? selinux_file_permission+0x82/0x460 [ 24.210930] ? security_file_permission+0x89/0x1e0 [ 24.215826] ? do_splice_direct+0x3c0/0x3c0 [ 24.220111] do_splice_to+0x10a/0x160 [ 24.223877] ? do_splice_to+0x10a/0x160 [ 24.227818] SyS_splice+0x1187/0x1610 [ 24.231598] ? SyS_futex+0x269/0x390 [ 24.235300] ? compat_SyS_vmsplice+0x250/0x250 [ 24.239861] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 24.244861] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 24.249610] entry_SYSCALL_64_fastpath+0x1f/0x96 [ 24.254339] RIP: 0033:0x446059 [ 24.257496] RSP: 002b:00007fac5f985d08 EFLAGS: 00000216 ORIG_RAX: 0000000000000113 [ 24.265169] RAX: ffffffffffffffda RBX: 00000000006f0054 RCX: 0000000000446059 [ 24.272417] RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 [ 24.279652] RBP: 00000000006f0050 R08: 0000000000000004 R09: 0000000000000000 [ 24.286900] R10: 0000000000000000 R11: 0000000000000216 R12: 00007fac5f985d20 [ 24.294135] R13: 702f7465