[ 38.058888][ T26] audit: type=1800 audit(1552231817.534:27): pid=7652 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [ 38.082428][ T26] audit: type=1800 audit(1552231817.534:28): pid=7652 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.867889][ T26] audit: type=1800 audit(1552231818.394:29): pid=7652 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 38.887326][ T26] audit: type=1800 audit(1552231818.394:30): pid=7652 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.60' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 46.326653][ T7806] [ 46.329040][ T7806] ====================================================== [ 46.336046][ T7806] WARNING: possible circular locking dependency detected [ 46.343057][ T7806] 5.0.0+ #15 Not tainted [ 46.347287][ T7806] ------------------------------------------------------ [ 46.354303][ T7806] syz-executor575/7806 is trying to acquire lock: [ 46.360708][ T7806] 0000000068f22ba5 (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x73/0x2d0 [ 46.369479][ T7806] [ 46.369479][ T7806] but task is already holding lock: [ 46.376851][ T7806] 00000000734ae4e8 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 46.385202][ T7806] [ 46.385202][ T7806] which lock already depends on the new lock. [ 46.385202][ T7806] [ 46.395595][ T7806] [ 46.395595][ T7806] the existing dependency chain (in reverse order) is: [ 46.404606][ T7806] [ 46.404606][ T7806] -> #1 (&mm->mmap_sem){++++}: [ 46.411564][ T7806] lock_acquire+0x16f/0x3f0 [ 46.416588][ T7806] __might_fault+0x15e/0x1e0 [ 46.421709][ T7806] _copy_to_user+0x30/0x120 [ 46.426735][ T7806] mon_bin_read+0x329/0x640 [ 46.431757][ T7806] do_iter_read+0x4a9/0x660 [ 46.436785][ T7806] vfs_readv+0xf0/0x160 [ 46.441460][ T7806] do_preadv+0x1c4/0x280 [ 46.446226][ T7806] __x64_sys_preadv+0x9a/0xf0 [ 46.451424][ T7806] do_syscall_64+0x103/0x610 [ 46.456535][ T7806] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.462933][ T7806] [ 46.462933][ T7806] -> #0 (&rp->fetch_lock){+.+.}: [ 46.470055][ T7806] __lock_acquire+0x239c/0x3fb0 [ 46.475423][ T7806] lock_acquire+0x16f/0x3f0 [ 46.480448][ T7806] __mutex_lock+0xf7/0x1310 [ 46.485474][ T7806] mutex_lock_nested+0x16/0x20 [ 46.490758][ T7806] mon_bin_vma_fault+0x73/0x2d0 [ 46.496126][ T7806] __do_fault+0x116/0x4e0 [ 46.500978][ T7806] __handle_mm_fault+0xf6c/0x3ec0 [ 46.506523][ T7806] handle_mm_fault+0x43f/0xb30 [ 46.511803][ T7806] __get_user_pages+0x7b6/0x1a40 [ 46.517262][ T7806] populate_vma_page_range+0x20d/0x2a0 [ 46.523238][ T7806] __mm_populate+0x204/0x380 [ 46.528349][ T7806] vm_mmap_pgoff+0x213/0x230 [ 46.533453][ T7806] ksys_mmap_pgoff+0x4aa/0x630 [ 46.538756][ T7806] __x64_sys_mmap+0xe9/0x1b0 [ 46.543866][ T7806] do_syscall_64+0x103/0x610 [ 46.548978][ T7806] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.555370][ T7806] [ 46.555370][ T7806] other info that might help us debug this: [ 46.555370][ T7806] [ 46.565587][ T7806] Possible unsafe locking scenario: [ 46.565587][ T7806] [ 46.573027][ T7806] CPU0 CPU1 [ 46.578381][ T7806] ---- ---- [ 46.583730][ T7806] lock(&mm->mmap_sem); [ 46.587959][ T7806] lock(&rp->fetch_lock); [ 46.594874][ T7806] lock(&mm->mmap_sem); [ 46.601621][ T7806] lock(&rp->fetch_lock); [ 46.606023][ T7806] [ 46.606023][ T7806] *** DEADLOCK *** [ 46.606023][ T7806] [ 46.614157][ T7806] 1 lock held by syz-executor575/7806: [ 46.619593][ T7806] #0: 00000000734ae4e8 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 46.628354][ T7806] [ 46.628354][ T7806] stack backtrace: [ 46.634237][ T7806] CPU: 0 PID: 7806 Comm: syz-executor575 Not tainted 5.0.0+ #15 [ 46.641852][ T7806] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.651900][ T7806] Call Trace: [ 46.655179][ T7806] dump_stack+0x172/0x1f0 [ 46.659509][ T7806] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 46.665566][ T7806] check_prev_add.constprop.0+0xf11/0x23c0 [ 46.671353][ T7806] ? check_usage+0x570/0x570 [ 46.675925][ T7806] ? depot_save_stack+0x1de/0x460 [ 46.680932][ T7806] ? graph_lock+0x7b/0x200 [ 46.685351][ T7806] ? __lockdep_reset_lock+0x450/0x450 [ 46.690709][ T7806] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.696951][ T7806] __lock_acquire+0x239c/0x3fb0 [ 46.701781][ T7806] ? depot_save_stack+0x1de/0x460 [ 46.706789][ T7806] ? mark_held_locks+0xf0/0xf0 [ 46.711558][ T7806] ? __do_fault+0x2b9/0x4e0 [ 46.716049][ T7806] lock_acquire+0x16f/0x3f0 [ 46.720534][ T7806] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.725545][ T7806] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.730546][ T7806] __mutex_lock+0xf7/0x1310 [ 46.735032][ T7806] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.740038][ T7806] ? fs_reclaim_acquire.part.0+0x30/0x30 [ 46.745652][ T7806] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.750656][ T7806] ? mutex_trylock+0x1e0/0x1e0 [ 46.755403][ T7806] ? ptlock_alloc+0x20/0x70 [ 46.759881][ T7806] ? rcu_read_lock_sched_held+0x110/0x130 [ 46.765577][ T7806] ? kmem_cache_alloc+0x32e/0x6f0 [ 46.770578][ T7806] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 46.776794][ T7806] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 46.783013][ T7806] mutex_lock_nested+0x16/0x20 [ 46.787757][ T7806] ? mutex_lock_nested+0x16/0x20 [ 46.792676][ T7806] mon_bin_vma_fault+0x73/0x2d0 [ 46.797515][ T7806] __do_fault+0x116/0x4e0 [ 46.801824][ T7806] ? mem_cgroup_try_charge_delay+0x6c/0xa0 [ 46.807614][ T7806] __handle_mm_fault+0xf6c/0x3ec0 [ 46.812622][ T7806] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 46.818147][ T7806] ? find_held_lock+0x35/0x130 [ 46.822890][ T7806] ? handle_mm_fault+0x322/0xb30 [ 46.827808][ T7806] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 46.834027][ T7806] ? kasan_check_read+0x11/0x20 [ 46.838858][ T7806] handle_mm_fault+0x43f/0xb30 [ 46.843598][ T7806] __get_user_pages+0x7b6/0x1a40 [ 46.848514][ T7806] ? follow_page_mask+0x19a0/0x19a0 [ 46.853693][ T7806] ? vma_set_page_prot+0x18c/0x240 [ 46.858786][ T7806] ? memset+0x32/0x40 [ 46.862747][ T7806] populate_vma_page_range+0x20d/0x2a0 [ 46.868183][ T7806] __mm_populate+0x204/0x380 [ 46.872756][ T7806] ? populate_vma_page_range+0x2a0/0x2a0 [ 46.878372][ T7806] vm_mmap_pgoff+0x213/0x230 [ 46.882947][ T7806] ? vma_is_stack_for_current+0xd0/0xd0 [ 46.888491][ T7806] ? ksys_dup3+0x3e0/0x3e0 [ 46.892886][ T7806] ksys_mmap_pgoff+0x4aa/0x630 [ 46.897633][ T7806] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 46.903247][ T7806] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.908693][ T7806] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.914136][ T7806] ? do_syscall_64+0x26/0x610 [ 46.918794][ T7806] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.924849][ T7806] __x64_sys_mmap+0xe9/0x1b0 [ 46.929421][ T7806] do_syscall_64+0x103/0x610 [ 46.933994][ T7806] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.939867][ T7806] RIP: 0033:0x449669 [ 46.943741][ T7806] Code: e8 9c b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 46.963332][ T7806] RSP: 002b:00007f0318e23cd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 46.971725][ T7806] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000449669 [ 46.979677][ T7806] RDX: 0000000000000013 RSI: 0000000000400000 RDI: 0000000020a05000 [ 46.987657][ T7806] RBP: 00000000006dac30 R08: 0000000000000005 R09: 0000000000000000 [ 46.995620][ T7806] R10: 0000000000008012 R11: 0000000000000246 R12: 00000000006dac3c [ 47.003572][ T7806] R13: 00007ffcb9fd36af R14: 00007f0318e249c0 R15: 20c49ba5e353f7cf