============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.3.5755/5950 is trying to acquire lock: ffffffff8fc04760 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x49/0x70 kernel/power/main.c:71 but task is already holding lock: ffffffff8fc04760 (system_transition_mutex){+.+.}-{4:4}, at: __do_sys_reboot kernel/reboot.c:774 [inline] ffffffff8fc04760 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0x223/0x460 kernel/reboot.c:738 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(system_transition_mutex); lock(system_transition_mutex); *** DEADLOCK *** May be due to missing lock nesting notation locks held by syz.3.5755/5950: 1, last CPU#0: #0: ffffffff8fc04760 (system_transition_mutex){+.+.}-{4:4}, at: __do_sys_reboot kernel/reboot.c:774 [inline] #0: ffffffff8fc04760 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0x223/0x460 kernel/reboot.c:738 stack backtrace: CPU: 0 UID: 0 PID: 5950 Comm: syz.3.5755 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085 check_deadlock kernel/locking/lockdep.c:3137 [inline] validate_chain kernel/locking/lockdep.c:3939 [inline] __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 lock_system_sleep+0x49/0x70 kernel/power/main.c:71 hibernate+0x162/0x680 kernel/power/hibernate.c:784 __do_sys_reboot kernel/reboot.c:816 [inline] __se_sys_reboot+0x2ba/0x460 kernel/reboot.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdb2419f809 Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 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 73 01 c3 48 c7 c1 d8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffff22cee98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a9 RAX: ffffffffffffffda RBX: 00007ffff22cefc8 RCX: 00007fdb2419f809 RDX: 00000000d000fce2 RSI: 0000000028121969 RDI: 00000000fee1dead RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffff22cefc8 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffff22cefb8 R13: 0000000000000002 R14: 00007fdb24222cc0 R15: 0000000000000002