[ 36.762823][ T25] audit: type=1800 audit(1552229843.348:30): pid=7535 uid=0 auid=4294967295 ses=4294967295 subj==unconfined 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 '10.128.0.120' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 43.955923][ T7692] [ 43.958264][ T7692] ====================================================== [ 43.965252][ T7692] WARNING: possible circular locking dependency detected [ 43.972572][ T7692] 5.0.0+ #15 Not tainted [ 43.978888][ T7692] ------------------------------------------------------ [ 43.985877][ T7692] syz-executor288/7692 is trying to acquire lock: [ 43.992256][ T7692] 000000008151ef6e (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x73/0x2d0 [ 44.001003][ T7692] [ 44.001003][ T7692] but task is already holding lock: [ 44.008358][ T7692] 00000000f36af9e8 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 44.016662][ T7692] [ 44.016662][ T7692] which lock already depends on the new lock. [ 44.016662][ T7692] [ 44.027039][ T7692] [ 44.027039][ T7692] the existing dependency chain (in reverse order) is: [ 44.036022][ T7692] [ 44.036022][ T7692] -> #1 (&mm->mmap_sem){++++}: [ 44.042947][ T7692] lock_acquire+0x16f/0x3f0 [ 44.047946][ T7692] __might_fault+0x15e/0x1e0 [ 44.053031][ T7692] _copy_to_user+0x30/0x120 [ 44.058036][ T7692] mon_bin_read+0x329/0x640 [ 44.063039][ T7692] do_iter_read+0x4a9/0x660 [ 44.068037][ T7692] vfs_readv+0xf0/0x160 [ 44.072684][ T7692] do_preadv+0x1c4/0x280 [ 44.077417][ T7692] __x64_sys_preadv+0x9a/0xf0 [ 44.082605][ T7692] do_syscall_64+0x103/0x610 [ 44.087693][ T7692] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.094073][ T7692] [ 44.094073][ T7692] -> #0 (&rp->fetch_lock){+.+.}: [ 44.101259][ T7692] __lock_acquire+0x239c/0x3fb0 [ 44.106601][ T7692] lock_acquire+0x16f/0x3f0 [ 44.111598][ T7692] __mutex_lock+0xf7/0x1310 [ 44.116592][ T7692] mutex_lock_nested+0x16/0x20 [ 44.121855][ T7692] mon_bin_vma_fault+0x73/0x2d0 [ 44.127200][ T7692] __do_fault+0x116/0x4e0 [ 44.132022][ T7692] __handle_mm_fault+0xf6c/0x3ec0 [ 44.137560][ T7692] handle_mm_fault+0x43f/0xb30 [ 44.142818][ T7692] __get_user_pages+0x7b6/0x1a40 [ 44.148245][ T7692] populate_vma_page_range+0x20d/0x2a0 [ 44.154198][ T7692] __mm_populate+0x204/0x380 [ 44.159283][ T7692] vm_mmap_pgoff+0x213/0x230 [ 44.164364][ T7692] ksys_mmap_pgoff+0x4aa/0x630 [ 44.169621][ T7692] __x64_sys_mmap+0xe9/0x1b0 [ 44.174703][ T7692] do_syscall_64+0x103/0x610 [ 44.179815][ T7692] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.186193][ T7692] [ 44.186193][ T7692] other info that might help us debug this: [ 44.186193][ T7692] [ 44.196390][ T7692] Possible unsafe locking scenario: [ 44.196390][ T7692] [ 44.203823][ T7692] CPU0 CPU1 [ 44.209162][ T7692] ---- ---- [ 44.214496][ T7692] lock(&mm->mmap_sem); [ 44.218725][ T7692] lock(&rp->fetch_lock); [ 44.225628][ T7692] lock(&mm->mmap_sem); [ 44.232358][ T7692] lock(&rp->fetch_lock); [ 44.236743][ T7692] [ 44.236743][ T7692] *** DEADLOCK *** [ 44.236743][ T7692] [ 44.244871][ T7692] 1 lock held by syz-executor288/7692: [ 44.250294][ T7692] #0: 00000000f36af9e8 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 44.259040][ T7692] [ 44.259040][ T7692] stack backtrace: [ 44.264904][ T7692] CPU: 0 PID: 7692 Comm: syz-executor288 Not tainted 5.0.0+ #15 [ 44.272502][ T7692] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.282547][ T7692] Call Trace: [ 44.285825][ T7692] dump_stack+0x172/0x1f0 [ 44.290131][ T7692] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 44.296170][ T7692] check_prev_add.constprop.0+0xf11/0x23c0 [ 44.301948][ T7692] ? check_usage+0x570/0x570 [ 44.306539][ T7692] ? depot_save_stack+0x1de/0x460 [ 44.311550][ T7692] ? graph_lock+0x7b/0x200 [ 44.315941][ T7692] ? __lockdep_reset_lock+0x450/0x450 [ 44.321288][ T7692] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 44.327498][ T7692] __lock_acquire+0x239c/0x3fb0 [ 44.332319][ T7692] ? depot_save_stack+0x1de/0x460 [ 44.337320][ T7692] ? mark_held_locks+0xf0/0xf0 [ 44.342055][ T7692] ? __do_fault+0x2b9/0x4e0 [ 44.346547][ T7692] lock_acquire+0x16f/0x3f0 [ 44.351030][ T7692] ? mon_bin_vma_fault+0x73/0x2d0 [ 44.356030][ T7692] ? mon_bin_vma_fault+0x73/0x2d0 [ 44.361055][ T7692] __mutex_lock+0xf7/0x1310 [ 44.365530][ T7692] ? mon_bin_vma_fault+0x73/0x2d0 [ 44.370528][ T7692] ? fs_reclaim_acquire.part.0+0x30/0x30 [ 44.376137][ T7692] ? mon_bin_vma_fault+0x73/0x2d0 [ 44.381142][ T7692] ? mutex_trylock+0x1e0/0x1e0 [ 44.385891][ T7692] ? ptlock_alloc+0x20/0x70 [ 44.390367][ T7692] ? rcu_read_lock_sched_held+0x110/0x130 [ 44.396075][ T7692] ? kmem_cache_alloc+0x32e/0x6f0 [ 44.401073][ T7692] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 44.407283][ T7692] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 44.413495][ T7692] mutex_lock_nested+0x16/0x20 [ 44.418234][ T7692] ? mutex_lock_nested+0x16/0x20 [ 44.423147][ T7692] mon_bin_vma_fault+0x73/0x2d0 [ 44.427970][ T7692] __do_fault+0x116/0x4e0 [ 44.432299][ T7692] ? mem_cgroup_try_charge_delay+0x6c/0xa0 [ 44.438079][ T7692] __handle_mm_fault+0xf6c/0x3ec0 [ 44.443076][ T7692] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 44.448592][ T7692] ? find_held_lock+0x35/0x130 [ 44.453331][ T7692] ? handle_mm_fault+0x322/0xb30 [ 44.458239][ T7692] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 44.464456][ T7692] ? kasan_check_read+0x11/0x20 [ 44.469277][ T7692] handle_mm_fault+0x43f/0xb30 [ 44.474012][ T7692] __get_user_pages+0x7b6/0x1a40 [ 44.478942][ T7692] ? follow_page_mask+0x19a0/0x19a0 [ 44.484113][ T7692] ? vma_set_page_prot+0x18c/0x240 [ 44.489196][ T7692] ? memset+0x32/0x40 [ 44.493154][ T7692] populate_vma_page_range+0x20d/0x2a0 [ 44.498582][ T7692] __mm_populate+0x204/0x380 [ 44.503145][ T7692] ? populate_vma_page_range+0x2a0/0x2a0 [ 44.508750][ T7692] vm_mmap_pgoff+0x213/0x230 [ 44.513321][ T7692] ? vma_is_stack_for_current+0xd0/0xd0 [ 44.518836][ T7692] ? ksys_dup3+0x3e0/0x3e0 [ 44.523227][ T7692] ksys_mmap_pgoff+0x4aa/0x630 [ 44.527961][ T7692] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 44.533568][ T7692] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 44.539005][ T7692] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 44.544450][ T7692] ? do_syscall_64+0x26/0x610 [ 44.549099][ T7692] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.555141][ T7692] __x64_sys_mmap+0xe9/0x1b0 [ 44.559718][ T7692] do_syscall_64+0x103/0x610 [ 44.564283][ T7692] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.570147][ T7692] RIP: 0033:0x449669 [ 44.574015][ T7692] 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 [ 44.593592][ T7692] RSP: 002b:00007f42af561cd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 44.601975][ T7692] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000449669 [ 44.609919][ T7692] RDX: 0000000000000013 RSI: 0000000000400000 RDI: 0000000020a05000 [ 44.617865][ T7692] RBP: 00000000006dac30 R08: 0000000000000005 R09: 0000000000000000 [ 44.625807][ T7692] R10: 0000000000008012 R11: 0000000000000246 R12: 00000000006dac3c [ 44.633753][ T7692] R13: 00007fffff8fbadf R14: 00007f42af5629c0 R15: 20c49ba5e353f7cf