================================ WARNING: inconsistent lock state 6.7.0-rc1-next-20231117-syzkaller #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. syz-executor.1/6303 [HC1[1]:SC0[0]:HE0:SE1] takes: ffff88808033ef18 (&sighand->siglock){?.+.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 {HARDIRQ-ON-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:530 [inline] ptrace_set_stopped kernel/ptrace.c:391 [inline] ptrace_attach+0x401/0x650 kernel/ptrace.c:478 __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a irq event stamp: 64 hardirqs last enabled at (63): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] hardirqs last enabled at (63): [] _raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:202 hardirqs last disabled at (64): [] sysvec_apic_timer_interrupt+0xe/0xb0 arch/x86/kernel/apic/apic.c:1076 softirqs last enabled at (0): [] copy_process+0x244c/0x9770 kernel/fork.c:2466 softirqs last disabled at (0): [<0000000000000000>] 0x0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sighand->siglock); lock(&sighand->siglock); *** DEADLOCK *** 2 locks held by syz-executor.1/6303: #0: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: kill_pid_info+0x22/0x2a0 kernel/signal.c:1496 #1: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #1: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #1: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x3f/0x340 kernel/signal.c:1405 stack backtrace: CPU: 0 PID: 6303 Comm: syz-executor.1 Not tainted 6.7.0-rc1-next-20231117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3970 [inline] valid_state kernel/locking/lockdep.c:4012 [inline] mark_lock_irq kernel/locking/lockdep.c:4215 [inline] mark_lock+0x91a/0xc50 kernel/locking/lockdep.c:4677 mark_usage kernel/locking/lockdep.c:4563 [inline] __lock_acquire+0x1347/0x3b10 kernel/locking/lockdep.c:5090 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 lock_task_sighand include/linux/sched/signal.h:748 [inline] do_send_sig_info kernel/signal.c:1309 [inline] group_send_sig_info+0x288/0x300 kernel/signal.c:1460 kill_pid_info+0x95/0x2a0 kernel/signal.c:1499 it_real_fn+0xbc/0x230 kernel/time/itimer.c:163 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:preempt_count_sub+0x46/0x160 kernel/sched/core.c:5888 Code: e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 d3 00 00 00 8b 0d c5 f4 25 11 85 c9 75 1b 65 8b 05 e2 2a a9 7e <89> c2 81 e2 ff ff ff 7f 39 d3 7f 13 81 fb fe 00 00 00 76 69 f7 db RSP: 0018:ffffc90004b37d60 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff8accbfe0 RDI: 0000000000000001 RBP: ffffc90004b37de0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8f18e357 R11: 0000000000000002 R12: ffff88801ef93d90 R13: ffff88801f9a0000 R14: 0000000000001b58 R15: 0000000000000000 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x2e/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] do_setitimer+0x410/0x580 kernel/time/itimer.c:238 __do_sys_setitimer kernel/time/itimer.c:349 [inline] __se_sys_setitimer kernel/time/itimer.c:332 [inline] __x64_sys_setitimer+0x1aa/0x360 kernel/time/itimer.c:332 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7f9703a7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f970470f0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000026 RAX: ffffffffffffffda RBX: 00007f9703b9bf80 RCX: 00007f9703a7cae9 RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00007f9703ac847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9703b9bf80 R15: 00007fff4bf36a18 ---------------- Code disassembly (best guess): 0: e0 07 loopne 0x9 2: 48 c1 e9 03 shr $0x3,%rcx 6: 83 c0 03 add $0x3,%eax 9: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx d: 38 d0 cmp %dl,%al f: 7c 08 jl 0x19 11: 84 d2 test %dl,%dl 13: 0f 85 d3 00 00 00 jne 0xec 19: 8b 0d c5 f4 25 11 mov 0x1125f4c5(%rip),%ecx # 0x1125f4e4 1f: 85 c9 test %ecx,%ecx 21: 75 1b jne 0x3e 23: 65 8b 05 e2 2a a9 7e mov %gs:0x7ea92ae2(%rip),%eax # 0x7ea92b0c * 2a: 89 c2 mov %eax,%edx <-- trapping instruction 2c: 81 e2 ff ff ff 7f and $0x7fffffff,%edx 32: 39 d3 cmp %edx,%ebx 34: 7f 13 jg 0x49 36: 81 fb fe 00 00 00 cmp $0xfe,%ebx 3c: 76 69 jbe 0xa7 3e: f7 db neg %ebx