[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 56.133874][ T25] audit: type=1800 audit(1570326843.056:25): pid=8534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 56.175166][ T25] audit: type=1800 audit(1570326843.066:26): pid=8534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 56.219476][ T25] audit: type=1800 audit(1570326843.066:27): pid=8534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.182' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 64.598839][ T8700] [ 64.601229][ T8700] ====================================================== [ 64.608243][ T8700] WARNING: possible circular locking dependency detected [ 64.616034][ T8700] 5.4.0-rc1+ #0 Not tainted [ 64.620541][ T8700] ------------------------------------------------------ [ 64.627569][ T8700] syz-executor940/8700 is trying to acquire lock: [ 64.633970][ T8700] ffff888091b2ce40 (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x73/0x2d0 [ 64.642720][ T8700] [ 64.642720][ T8700] but task is already holding lock: [ 64.650067][ T8700] ffff88808b3f2c58 (&mm->mmap_sem#2){++++}, at: __mm_populate+0x270/0x380 [ 64.658555][ T8700] [ 64.658555][ T8700] which lock already depends on the new lock. [ 64.658555][ T8700] [ 64.668936][ T8700] [ 64.668936][ T8700] the existing dependency chain (in reverse order) is: [ 64.677929][ T8700] [ 64.677929][ T8700] -> #1 (&mm->mmap_sem#2){++++}: [ 64.685131][ T8700] __might_fault+0x15e/0x1e0 [ 64.690614][ T8700] _copy_to_user+0x30/0x160 [ 64.695620][ T8700] mon_bin_read+0x329/0x640 [ 64.700629][ T8700] __vfs_read+0x8a/0x110 [ 64.705593][ T8700] vfs_read+0x1f0/0x440 [ 64.710271][ T8700] ksys_read+0x14f/0x290 [ 64.715031][ T8700] __x64_sys_read+0x73/0xb0 [ 64.720055][ T8700] do_syscall_64+0xfa/0x760 [ 64.725069][ T8700] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.731461][ T8700] [ 64.731461][ T8700] -> #0 (&rp->fetch_lock){+.+.}: [ 64.738577][ T8700] __lock_acquire+0x2596/0x4a00 [ 64.743949][ T8700] lock_acquire+0x190/0x410 [ 64.748972][ T8700] __mutex_lock+0x156/0x13c0 [ 64.754076][ T8700] mutex_lock_nested+0x16/0x20 [ 64.759344][ T8700] mon_bin_vma_fault+0x73/0x2d0 [ 64.764712][ T8700] __do_fault+0x111/0x540 [ 64.769544][ T8700] __handle_mm_fault+0xce8/0x4040 [ 64.775067][ T8700] handle_mm_fault+0x3b7/0xaa0 [ 64.780391][ T8700] __get_user_pages+0x7d4/0x1b30 [ 64.785840][ T8700] populate_vma_page_range+0x20d/0x2a0 [ 64.792198][ T8700] __mm_populate+0x204/0x380 [ 64.797358][ T8700] vm_mmap_pgoff+0x213/0x230 [ 64.802598][ T8700] ksys_mmap_pgoff+0x4aa/0x630 [ 64.807866][ T8700] __x64_sys_mmap+0xe9/0x1b0 [ 64.812977][ T8700] do_syscall_64+0xfa/0x760 [ 64.818263][ T8700] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 64.824682][ T8700] [ 64.824682][ T8700] other info that might help us debug this: [ 64.824682][ T8700] [ 64.834980][ T8700] Possible unsafe locking scenario: [ 64.834980][ T8700] [ 64.842448][ T8700] CPU0 CPU1 [ 64.847802][ T8700] ---- ---- [ 64.853157][ T8700] lock(&mm->mmap_sem#2); [ 64.857556][ T8700] lock(&rp->fetch_lock); [ 64.864462][ T8700] lock(&mm->mmap_sem#2); [ 64.871381][ T8700] lock(&rp->fetch_lock); [ 64.875786][ T8700] [ 64.875786][ T8700] *** DEADLOCK *** [ 64.875786][ T8700] [ 64.884001][ T8700] 1 lock held by syz-executor940/8700: [ 64.889450][ T8700] #0: ffff88808b3f2c58 (&mm->mmap_sem#2){++++}, at: __mm_populate+0x270/0x380 [ 64.898381][ T8700] [ 64.898381][ T8700] stack backtrace: [ 64.904269][ T8700] CPU: 0 PID: 8700 Comm: syz-executor940 Not tainted 5.4.0-rc1+ #0 [ 64.912163][ T8700] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.922207][ T8700] Call Trace: [ 64.925484][ T8700] dump_stack+0x172/0x1f0 [ 64.929807][ T8700] print_circular_bug.isra.0.cold+0x163/0x172 [ 64.935856][ T8700] check_noncircular+0x32e/0x3e0 [ 64.940786][ T8700] ? print_circular_bug.isra.0+0x230/0x230 [ 64.946570][ T8700] ? alloc_list_entry+0xc0/0xc0 [ 64.951403][ T8700] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 64.957627][ T8700] ? find_first_zero_bit+0x9a/0xc0 [ 64.962716][ T8700] __lock_acquire+0x2596/0x4a00 [ 64.967546][ T8700] ? stack_depot_save+0x25a/0x450 [ 64.972552][ T8700] ? mark_held_locks+0xf0/0xf0 [ 64.977556][ T8700] lock_acquire+0x190/0x410 [ 64.982070][ T8700] ? mon_bin_vma_fault+0x73/0x2d0 [ 64.989079][ T8700] __mutex_lock+0x156/0x13c0 [ 64.993659][ T8700] ? mon_bin_vma_fault+0x73/0x2d0 [ 64.998678][ T8700] ? __kasan_check_read+0x11/0x20 [ 65.003694][ T8700] ? mon_bin_vma_fault+0x73/0x2d0 [ 65.008695][ T8700] ? mutex_trylock+0x2d0/0x2d0 [ 65.013438][ T8700] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 65.018970][ T8700] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 65.024950][ T8700] ? __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 65.030760][ T8700] ? kmem_cache_alloc+0x364/0x710 [ 65.035764][ T8700] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 65.041994][ T8700] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 65.048488][ T8700] mutex_lock_nested+0x16/0x20 [ 65.053241][ T8700] ? mutex_lock_nested+0x16/0x20 [ 65.058177][ T8700] mon_bin_vma_fault+0x73/0x2d0 [ 65.063020][ T8700] __do_fault+0x111/0x540 [ 65.067347][ T8700] ? mem_cgroup_try_charge_delay+0x6c/0xa0 [ 65.073153][ T8700] __handle_mm_fault+0xce8/0x4040 [ 65.078171][ T8700] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 65.083694][ T8700] ? handle_mm_fault+0x292/0xaa0 [ 65.088618][ T8700] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 65.094859][ T8700] ? __kasan_check_read+0x11/0x20 [ 65.100126][ T8700] handle_mm_fault+0x3b7/0xaa0 [ 65.104873][ T8700] __get_user_pages+0x7d4/0x1b30 [ 65.109801][ T8700] ? mark_held_locks+0xf0/0xf0 [ 65.114563][ T8700] ? follow_page_mask+0x1cf0/0x1cf0 [ 65.119748][ T8700] ? __mm_populate+0x270/0x380 [ 65.124497][ T8700] ? memset+0x32/0x40 [ 65.128474][ T8700] populate_vma_page_range+0x20d/0x2a0 [ 65.133916][ T8700] __mm_populate+0x204/0x380 [ 65.138493][ T8700] ? populate_vma_page_range+0x2a0/0x2a0 [ 65.144116][ T8700] ? __kasan_check_write+0x14/0x20 [ 65.149204][ T8700] ? up_write+0x155/0x490 [ 65.153539][ T8700] vm_mmap_pgoff+0x213/0x230 [ 65.158111][ T8700] ? randomize_stack_top+0x110/0x110 [ 65.163395][ T8700] ? ksys_dup3+0x3e0/0x3e0 [ 65.167813][ T8700] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 65.173946][ T8700] ksys_mmap_pgoff+0x4aa/0x630 [ 65.178690][ T8700] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 65.184309][ T8700] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 65.189744][ T8700] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 65.195181][ T8700] ? do_syscall_64+0x26/0x760 [ 65.199849][ T8700] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 65.205896][ T8700] __x64_sys_mmap+0xe9/0x1b0 [ 65.210477][ T8700] do_syscall_64+0xfa/0x760 [ 65.214963][ T8700] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 65.220842][ T8700] RIP: 0033:0x44a729 [ 65.224715][ T8700] Code: e8 0c e8 ff ff 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 7b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 executing program executing program executing program executing program executing program executing program [ 65.244829][ T8700] RSP: 002b:00007ff71ae06cd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 65.253409][ T8700] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a729 [ 65.261359][ T8700] RDX: 000000000300001f RSI: 0000000000003000 RDI: 0000000020ffa000 [ 65.269312][ T8700] RBP: 00000000006dbc20 R08: 0000000000000004 R09: 0000000000000000 [ 65.277270][ T8700] R10: 0000000000002012 R11: 0000000000000246 R12: 00000000006dbc2c [ 65.285220][ T8700] R13: 00007fffbb3ba1ff R14: 00007ff71ae079c0 R15: 00000000006dbc20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program