Warning: Permanently added '10.128.10.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 52.050326][ T1] [ 52.050326][ T8427] [ 52.050336][ T1] ============================= [ 52.050341][ T1] WARNING: suspicious RCU usage [ 52.050346][ T1] 5.11.0-rc5-syzkaller #0 Not tainted [ 52.052677][ T8427] ============================================ [ 52.052684][ T8427] WARNING: possible recursive locking detected [ 52.054994][ T1] ----------------------------- [ 52.055000][ T1] kernel/sched/core.c:7932 Illegal context switch in RCU-sched read-side critical section! [ 52.059818][ T8427] 5.11.0-rc5-syzkaller #0 Not tainted [ 52.059828][ T8427] -------------------------------------------- [ 52.059833][ T8427] syz-executor943/8427 is trying to acquire lock: [ 52.059840][ T8427] ffff888031e620f0 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: ovl_dir_real_file+0x20b/0x310 [ 52.059903][ T8427] [ 52.059903][ T8427] but task is already holding lock: [ 52.059907][ T8427] ffff888031e620f0 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: ovl_ioctl+0x2fb/0x960 [ 52.069366][ T1] [ 52.069366][ T1] other info that might help us debug this: [ 52.069366][ T1] [ 52.070116][ T8427] [ 52.070116][ T8427] other info that might help us debug this: [ 52.070123][ T8427] Possible unsafe locking scenario: [ 52.070123][ T8427] [ 52.077396][ T1] [ 52.077396][ T1] rcu_scheduler_active = 2, debug_locks = 0 [ 52.082502][ T8427] CPU0 [ 52.082508][ T8427] ---- [ 52.088679][ T1] no locks held by systemd/1. [ 52.097301][ T8427] lock(&ovl_i_mutex_dir_key[depth]); [ 52.097324][ T8427] lock(&ovl_i_mutex_dir_key[depth]); [ 52.097333][ T8427] [ 52.097333][ T8427] *** DEADLOCK *** [ 52.097333][ T8427] [ 52.097336][ T8427] May be due to missing lock nesting notation [ 52.097336][ T8427] [ 52.097340][ T8427] 2 locks held by syz-executor943/8427: [ 52.097350][ T8427] #0: ffff88802d64c460 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x250 [ 52.097395][ T8427] #1: ffff888031e620f0 ( [ 52.105134][ T1] [ 52.105134][ T1] stack backtrace: [ 52.108928][ T8427] &ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: ovl_ioctl+0x2fb/0x960 [ 52.108968][ T8427] [ 52.108968][ T8427] stack backtrace: [ 52.108973][ T8427] CPU: 1 PID: 8427 Comm: syz-executor943 Not tainted 5.11.0-rc5-syzkaller #0 [ 52.108988][ T8427] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.109003][ T8427] Call Trace: [ 52.109011][ T8427] dump_stack+0x137/0x1be [ 52.109029][ T8427] ? wake_up_klogd+0xb2/0xf0 [ 52.289378][ T8427] __lock_acquire+0x2333/0x5e90 [ 52.294771][ T8427] ? rcu_read_lock_sched_held+0x41/0xb0 [ 52.301055][ T8427] lock_acquire+0x114/0x5e0 [ 52.305576][ T8427] ? ovl_dir_real_file+0x20b/0x310 [ 52.310692][ T8427] down_write+0x56/0x120 [ 52.314987][ T8427] ? ovl_dir_real_file+0x20b/0x310 [ 52.320222][ T8427] ovl_dir_real_file+0x20b/0x310 [ 52.325171][ T8427] ovl_ioctl+0x4de/0x960 [ 52.330056][ T8427] ? asan.module_dtor+0x20/0x20 [ 52.334914][ T8427] __se_sys_ioctl+0xfb/0x170 [ 52.339510][ T8427] do_syscall_64+0x2d/0x70 [ 52.344023][ T8427] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.350188][ T8427] RIP: 0033:0x4403c9 [ 52.354093][ T8427] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 52.374152][ T8427] RSP: 002b:00007ffd0371af08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 52.382574][ T8427] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004403c9 [ 52.390593][ T8427] RDX: 0000000000000000 RSI: 0000000040086602 RDI: 0000000000000003 [ 52.399186][ T8427] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 52.407245][ T8427] R10: 0000000000401c60 R11: 0000000000000246 R12: 0000000000401bd0 [ 52.415218][ T8427] R13: 0000000000401c60 R14: 0000000000000000 R15: 0000000000000000 [ 52.423205][ T1] CPU: 0 PID: 1 Comm: systemd Not tainted 5.11.0-rc5-syzkaller #0 [ 52.431049][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.441133][ T1] Call Trace: [ 52.444423][ T1] dump_stack+0x137/0x1be [ 52.448734][ T1] ___might_sleep+0xb4/0x530 [ 52.453304][ T1] __mutex_lock_common+0x4e/0x2f00 [ 52.458391][ T1] ? step_into+0x3cc/0x1e60 [ 52.462879][ T1] ? memcpy+0x3c/0x60 [ 52.466836][ T1] ? step_into+0x3cc/0x1e60 [ 52.471311][ T1] ? kernfs_iop_permission+0x66/0x2f0 [ 52.476658][ T1] ? lookup_fast+0x339/0x6f0 [ 52.481224][ T1] ? kernfs_evict_inode+0x60/0x60 [ 52.486224][ T1] mutex_lock_nested+0x1a/0x20 [ 52.490983][ T1] kernfs_iop_permission+0x66/0x2f0 [ 52.496159][ T1] ? inode_permission+0x22c/0x4a0 [ 52.501161][ T1] ? kernfs_evict_inode+0x60/0x60 [ 52.506169][ T1] inode_permission+0x234/0x4a0 [ 52.511014][ T1] link_path_walk+0x226/0xc10 [ 52.515681][ T1] path_openat+0x1f5/0x37a0 [ 52.520167][ T1] ? alloc_fd+0x583/0x620 [ 52.524476][ T1] do_filp_open+0x191/0x3a0 [ 52.528960][ T1] ? _raw_spin_unlock+0x24/0x40 [ 52.533788][ T1] ? alloc_fd+0x583/0x620 [ 52.538097][ T1] do_sys_openat2+0xba/0x380 [ 52.542665][ T1] __x64_sys_open+0x1af/0x1e0 [ 52.547338][ T1] do_syscall_64+0x2d/0x70 [ 52.551744][ T1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.557652][ T1] RIP: 0033:0x7fdaf5f1370d [ 52.562052][ T1] Code: 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 47 9e 01 00 48 89 d0 48 83 c4 08 48 3d 01 [ 52.581656][ T1] RSP: 002b:00007ffedccb56f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 [ 52.590056][ T1] RAX: ffffffffffffffda RBX: 000055b998e80590 RCX: 00007fdaf5f1370d [ 52.598020][ T1] RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffedccb57d0 [ 52.605988][ T1] RBP: 0000000000000008 R08: 0000000000000008 R09: 0000000000000001 [ 52.613936][ T1] R10: 0000000000080000 R11: 0000000000000293 R12: 00007fdaf764d7b4 [ 52.621885][ T1] R13: 0000000000000001 R14: 000055b998d5ad60 R15: 00007ffedccb57d0