[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.60' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 50.064303][ T8379] [ 50.066806][ T8379] ====================================================== [ 50.073916][ T8379] WARNING: possible circular locking dependency detected [ 50.077203][ T8380] overlayfs: upperdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection. [ 50.080932][ T8379] 5.13.0-rc1-syzkaller #0 Not tainted [ 50.100832][ T8379] ------------------------------------------------------ [ 50.107906][ T8379] syz-executor730/8379 is trying to acquire lock: [ 50.114297][ T8379] ffff888017bba620 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x75a/0x1ba0 [ 50.123768][ T8379] [ 50.123768][ T8379] but task is already holding lock: [ 50.131194][ T8379] ffff888148252460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 [ 50.139985][ T8379] [ 50.139985][ T8379] which lock already depends on the new lock. [ 50.139985][ T8379] [ 50.151509][ T8379] [ 50.151509][ T8379] the existing dependency chain (in reverse order) is: [ 50.160607][ T8379] [ 50.160607][ T8379] -> #1 (sb_writers#5){.+.+}-{0:0}: [ 50.168056][ T8379] lock_acquire+0x17f/0x720 [ 50.173325][ T8379] sb_start_write+0x4f/0x180 [ 50.178441][ T8379] mnt_want_write+0x3b/0x80 [ 50.183449][ T8379] ovl_maybe_copy_up+0x117/0x180 [ 50.189064][ T8379] ovl_open+0xa2/0x200 [ 50.193664][ T8379] do_dentry_open+0x7cb/0x1010 [ 50.199197][ T8379] dentry_open+0xc6/0x120 [ 50.204293][ T8379] ima_calc_file_hash+0x157/0x1b00 [ 50.210068][ T8379] ima_collect_measurement+0x283/0x520 [ 50.216059][ T8379] process_measurement+0xf79/0x1ba0 [ 50.222131][ T8379] ima_file_check+0xe0/0x130 [ 50.227257][ T8379] path_openat+0x293d/0x39b0 [ 50.232359][ T8379] do_filp_open+0x221/0x460 [ 50.237359][ T8379] do_sys_openat2+0x124/0x460 [ 50.242556][ T8379] __x64_sys_open+0x221/0x270 [ 50.248261][ T8379] do_syscall_64+0x3f/0xb0 [ 50.253262][ T8379] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 50.259662][ T8379] [ 50.259662][ T8379] -> #0 (&iint->mutex){+.+.}-{3:3}: [ 50.267029][ T8379] check_prevs_add+0x4f9/0x5b60 [ 50.272379][ T8379] __lock_acquire+0x4307/0x6040 [ 50.277832][ T8379] lock_acquire+0x17f/0x720 [ 50.282830][ T8379] __mutex_lock_common+0x1bd/0x2e50 [ 50.288609][ T8379] mutex_lock_nested+0x1a/0x20 [ 50.293867][ T8379] process_measurement+0x75a/0x1ba0 [ 50.299562][ T8379] ima_file_check+0xe0/0x130 [ 50.304733][ T8379] path_openat+0x293d/0x39b0 [ 50.309815][ T8379] do_filp_open+0x221/0x460 [ 50.314816][ T8379] do_sys_openat2+0x124/0x460 [ 50.320009][ T8379] __x64_sys_openat+0x243/0x290 [ 50.325442][ T8379] do_syscall_64+0x3f/0xb0 [ 50.330357][ T8379] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 50.336769][ T8379] [ 50.336769][ T8379] other info that might help us debug this: [ 50.336769][ T8379] [ 50.347061][ T8379] Possible unsafe locking scenario: [ 50.347061][ T8379] [ 50.354485][ T8379] CPU0 CPU1 [ 50.359823][ T8379] ---- ---- [ 50.365287][ T8379] lock(sb_writers#5); [ 50.369537][ T8379] lock(&iint->mutex); [ 50.376357][ T8379] lock(sb_writers#5); [ 50.383034][ T8379] lock(&iint->mutex); [ 50.387191][ T8379] [ 50.387191][ T8379] *** DEADLOCK *** [ 50.387191][ T8379] [ 50.395324][ T8379] 1 lock held by syz-executor730/8379: [ 50.400778][ T8379] #0: ffff888148252460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 [ 50.409911][ T8379] [ 50.409911][ T8379] stack backtrace: [ 50.415796][ T8379] CPU: 0 PID: 8379 Comm: syz-executor730 Not tainted 5.13.0-rc1-syzkaller #0 [ 50.424533][ T8379] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.434766][ T8379] Call Trace: [ 50.438118][ T8379] dump_stack+0x202/0x31e [ 50.442430][ T8379] ? show_regs_print_info+0x12/0x12 [ 50.447606][ T8379] ? log_buf_vmcoreinfo_setup+0x498/0x498 [ 50.453307][ T8379] ? save_trace+0x5a/0x9f0 [ 50.457719][ T8379] print_circular_bug+0xb17/0xdc0 [ 50.462724][ T8379] ? hlock_conflict+0x1f0/0x1f0 [ 50.467553][ T8379] ? __bfs+0x369/0x700 [ 50.471599][ T8379] ? check_path+0x40/0x40 [ 50.475905][ T8379] ? noop_count+0x30/0x30 [ 50.480299][ T8379] ? save_trace+0x5a/0x9f0 [ 50.484694][ T8379] check_noncircular+0x2cc/0x390 [ 50.489611][ T8379] ? add_chain_block+0x850/0x850 [ 50.494527][ T8379] ? hlock_conflict+0x54/0x1f0 [ 50.499295][ T8379] ? __bfs+0x369/0x700 [ 50.503355][ T8379] ? check_path+0x40/0x40 [ 50.507661][ T8379] check_prevs_add+0x4f9/0x5b60 [ 50.512492][ T8379] ? __bfs+0x369/0x700 [ 50.516797][ T8379] ? reacquire_held_locks+0x5f0/0x5f0 [ 50.522369][ T8379] ? check_path+0x40/0x40 [ 50.526692][ T8379] ? noop_count+0x30/0x30 [ 50.531146][ T8379] ? check_prevs_add+0x1c41/0x5b60 [ 50.536237][ T8379] ? reacquire_held_locks+0x5f0/0x5f0 [ 50.541603][ T8379] ? check_prevs_add+0x1c41/0x5b60 [ 50.547193][ T8379] ? mark_lock+0x199/0x1eb0 [ 50.551684][ T8379] ? __lock_acquire+0x13b0/0x6040 [ 50.556692][ T8379] ? __bfs+0x700/0x700 [ 50.560744][ T8379] ? mark_lock+0x199/0x1eb0 [ 50.565248][ T8379] ? __bfs+0x700/0x700 [ 50.569310][ T8379] ? __bfs+0x700/0x700 [ 50.573450][ T8379] ? __pv_queued_spin_lock_slowpath+0x9a0/0xcb0 [ 50.579831][ T8379] ? __pv_queued_spin_unlock_slowpath+0x2e0/0x2e0 [ 50.586608][ T8379] ? mark_lock+0x199/0x1eb0 [ 50.591147][ T8379] ? mark_lock+0x199/0x1eb0 [ 50.595654][ T8379] ? lockdep_lock+0x1bc/0x2c0 [ 50.600342][ T8379] ? lockdep_count_forward_deps+0x240/0x240 [ 50.606229][ T8379] __lock_acquire+0x4307/0x6040 [ 50.611165][ T8379] ? trace_lock_acquire+0x180/0x180 [ 50.616386][ T8379] ? lockdep_unlock+0x145/0x2e0 [ 50.621237][ T8379] ? lockdep_lock+0x2c0/0x2c0 [ 50.625897][ T8379] ? __lock_acquire+0x147f/0x6040 [ 50.630916][ T8379] ? __lock_acquire+0x438b/0x6040 [ 50.635924][ T8379] ? rcu_read_lock_sched_held+0x87/0x110 [ 50.641564][ T8379] ? __bpf_trace_rcu_stall_warning+0x10/0x10 [ 50.647542][ T8379] lock_acquire+0x17f/0x720 [ 50.652154][ T8379] ? process_measurement+0x75a/0x1ba0 [ 50.657590][ T8379] ? read_lock_is_recursive+0x10/0x10 [ 50.663312][ T8379] ? process_measurement+0x712/0x1ba0 [ 50.668790][ T8379] ? rcu_read_lock_sched_held+0x87/0x110 [ 50.674419][ T8379] ? __might_sleep+0x100/0x100 [ 50.679357][ T8379] __mutex_lock_common+0x1bd/0x2e50 [ 50.684556][ T8379] ? process_measurement+0x75a/0x1ba0 [ 50.689928][ T8379] ? __lock_acquire+0x6040/0x6040 [ 50.694953][ T8379] ? process_measurement+0x75a/0x1ba0 [ 50.700303][ T8379] ? integrity_inode_get+0x296/0x300 [ 50.705675][ T8379] ? mutex_lock_io_nested+0x60/0x60 [ 50.711028][ T8379] ? up_write+0x12c/0x4d0 [ 50.715350][ T8379] ? __up_read+0x790/0x790 [ 50.719755][ T8379] ? integrity_inode_get+0x296/0x300 [ 50.725034][ T8379] mutex_lock_nested+0x1a/0x20 [ 50.729788][ T8379] process_measurement+0x75a/0x1ba0 [ 50.735073][ T8379] ? ima_file_mmap+0x150/0x150 [ 50.739935][ T8379] ? rcu_lock_release+0x5/0x20 [ 50.744702][ T8379] ? __lock_acquire+0x6040/0x6040 [ 50.749926][ T8379] ? ext4_file_open+0x2d2/0x8c0 [ 50.754776][ T8379] ? smk_of_task_struct_subj+0x1bd/0x1d0 [ 50.760534][ T8379] ? smack_task_getsecid_subj+0x22/0x80 [ 50.766252][ T8379] ima_file_check+0xe0/0x130 [ 50.770838][ T8379] ? ima_bprm_check+0x280/0x280 [ 50.775672][ T8379] path_openat+0x293d/0x39b0 [ 50.780253][ T8379] ? do_filp_open+0x460/0x460 [ 50.784924][ T8379] ? alloc_fd+0x5eb/0x690 [ 50.789238][ T8379] ? rcu_read_lock_sched_held+0x87/0x110 [ 50.794961][ T8379] ? __bpf_trace_rcu_stall_warning+0x10/0x10 [ 50.800983][ T8379] do_filp_open+0x221/0x460 [ 50.805481][ T8379] ? vfs_tmpfile+0x230/0x230 [ 50.810061][ T8379] ? alloc_fd+0x5eb/0x690 [ 50.814382][ T8379] ? do_raw_spin_unlock+0x134/0x8a0 [ 50.819563][ T8379] ? _raw_spin_unlock+0x24/0x40 [ 50.824421][ T8379] ? alloc_fd+0x5eb/0x690 [ 50.828730][ T8379] do_sys_openat2+0x124/0x460 [ 50.833520][ T8379] ? __context_tracking_exit+0x7a/0xd0 [ 50.839063][ T8379] ? do_sys_open+0x220/0x220 [ 50.843642][ T8379] __x64_sys_openat+0x243/0x290 [ 50.848565][ T8379] ? __ia32_sys_open+0x270/0x270 [ 50.853569][ T8379] ? syscall_enter_from_user_mode+0x2e/0x1c0 [ 50.859557][ T8379] ? lockdep_hardirqs_on+0x8d/0x130 [ 50.864733][ T8379] ? syscall_enter_from_user_mode+0x2e/0x1c0 [ 50.870789][ T8379] do_syscall_64+0x3f/0xb0 [ 50.875197][ T8379] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 50.881079][ T8379] RIP: 0033:0x444de9 [ 50.885069][ T8379] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 50.904674][ T8379] RSP: 002b:00007f208b9f22f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 50.913175][ T8379] RAX: ffffffffffffffda RBX: 0000000