====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00242-g36534d3c5453 #0 Not tainted ------------------------------------------------------ syz-executor.4/5608 is trying to acquire lock: ffff8880b9438828 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9438828 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 but task is already holding lock: ffff88801f3dc618 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] ffff88801f3dc618 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 signal_wake_up_state+0xb4/0x120 kernel/signal.c:773 signal_wake_up include/linux/sched/signal.h:448 [inline] complete_signal+0x94a/0xcf0 kernel/signal.c:1065 __send_signal_locked+0xb1b/0xdc0 kernel/signal.c:1185 do_notify_parent+0xd96/0x10a0 kernel/signal.c:2141 exit_notify kernel/exit.c:753 [inline] do_exit+0x181d/0x27e0 kernel/exit.c:894 do_group_exit+0x207/0x2c0 kernel/exit.c:1023 __do_sys_exit_group kernel/exit.c:1034 [inline] __se_sys_exit_group kernel/exit.c:1032 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&sighand->siglock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2d0 kernel/signal.c:1412 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1451 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 bpf_prog_e6e9b5170a793889+0x11/0x22 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2446 __traceiter_mmap_lock_acquire_returned+0x93/0xf0 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_write_lock_killable include/linux/mmap_lock.h:123 [inline] dup_mmap kernel/fork.c:638 [inline] dup_mm kernel/fork.c:1688 [inline] copy_mm+0x1f8c/0x2020 kernel/fork.c:1737 copy_process+0x187a/0x3dc0 kernel/fork.c:2390 kernel_clone+0x226/0x8f0 kernel/fork.c:2797 __do_sys_clone kernel/fork.c:2940 [inline] __se_sys_clone kernel/fork.c:2924 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2924 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (lock#10){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x9af/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 bpf_prog_e6cf5f9c69743609+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:682 [inline] bpf_prog_run include/linux/filter.h:698 [inline] bpf_prog_run_array include/linux/bpf.h:2103 [inline] trace_call_bpf+0x3f5/0x8a0 kernel/trace/bpf_trace.c:147 perf_trace_run_bpf_submit+0x7c/0x1d0 kernel/events/core.c:10269 perf_trace_lock+0x388/0x490 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x986/0x9f0 kernel/locking/lockdep.c:5765 rcu_lock_release include/linux/rcupdate.h:339 [inline] rcu_read_unlock include/linux/rcupdate.h:812 [inline] select_task_rq_fair+0x78d/0x3b60 kernel/sched/fair.c:8252 select_task_rq kernel/sched/core.c:3637 [inline] try_to_wake_up+0x641/0x1470 kernel/sched/core.c:4363 wake_up_process kernel/sched/core.c:4510 [inline] wake_up_q+0xc8/0x120 kernel/sched/core.c:1029 futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199 do_futex+0x392/0x560 kernel/futex/syscalls.c:107 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: lock#10 --> &sighand->siglock --> &p->pi_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->pi_lock); lock(&sighand->siglock); lock(&p->pi_lock); lock(lock#10); *** DEADLOCK *** 4 locks held by syz-executor.4/5608: #0: ffff88801f3dc618 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline] #0: ffff88801f3dc618 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262 #1: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: select_task_rq_fair+0x3b4/0x3b60 kernel/sched/fair.c:8219 #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xbc/0x8a0 #3: ffff88807e97c418 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #3: ffff88807e97c418 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x237/0x9d0 kernel/bpf/stackmap.c:141 stack backtrace: CPU: 0 PID: 5608 Comm: syz-executor.4 Not tainted 6.10.0-rc2-syzkaller-00242-g36534d3c5453 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x630 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:164 [inline] stack_map_get_build_id_offset+0x9af/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 bpf_prog_e6cf5f9c69743609+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:682 [inline] bpf_prog_run include/linux/filter.h:698 [inline] bpf_prog_run_array include/linux/bpf.h:2103 [inline] trace_call_bpf+0x3f5/0x8a0 kernel/trace/bpf_trace.c:147 perf_trace_run_bpf_submit+0x7c/0x1d0 kernel/events/core.c:10269 perf_trace_lock+0x388/0x490 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x986/0x9f0 kernel/locking/lockdep.c:5765 rcu_lock_release include/linux/rcupdate.h:339 [inline] rcu_read_unlock include/linux/rcupdate.h:812 [inline] select_task_rq_fair+0x78d/0x3b60 kernel/sched/fair.c:8252 select_task_rq kernel/sched/core.c:3637 [inline] try_to_wake_up+0x641/0x1470 kernel/sched/core.c:4363 wake_up_process kernel/sched/core.c:4510 [inline] wake_up_q+0xc8/0x120 kernel/sched/core.c:1029 futex_wake+0x523/0x5c0 kernel/futex/waitwake.c:199 do_futex+0x392/0x560 kernel/futex/syscalls.c:107 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f45d0e7cea9 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:00007f45d1c83178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f45d0fb3f88 RCX: 00007f45d0e7cea9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f45d0fb3f8c RBP: 00007f45d0fb3f80 R08: 7fffffffffffffff R09: 00007f45d1c836c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f45d0fb3f8c R13: 000000000000000b R14: 00007ffff0ca0270 R15: 00007ffff0ca0358