====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-04485-gfa5ef655615a #0 Not tainted ------------------------------------------------------ syz.3.912/8422 is trying to acquire lock: ffff8880b9438798 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9438798 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_start_locking+0x83/0x620 mm/mmap_lock.c:230 but task is already holding lock: ffff8880b943e858 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1435 [inline] rq_lock_irqsave kernel/sched/sched.h:1700 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1749 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:10245 exit_signals+0x2a1/0x5c0 kernel/signal.c:3022 do_exit+0x6b4/0x27f0 kernel/exit.c:834 __do_sys_exit kernel/exit.c:993 [inline] __se_sys_exit kernel/exit.c:991 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:991 x64_sys_call+0x2622/0x2640 arch/x86/include/generated/asm/syscalls_64.h:61 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:5753 __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 0xffffffffa0000965 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:2406 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2449 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:634 [inline] dup_mm kernel/fork.c:1671 [inline] copy_mm+0x1e9a/0x1f30 kernel/fork.c:1720 copy_process+0x187a/0x3dc0 kernel/fork.c:2373 kernel_clone+0x226/0x8f0 kernel/fork.c:2780 __do_sys_clone kernel/fork.c:2923 [inline] __se_sys_clone kernel/fork.c:2907 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2907 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:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x620 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:162 [inline] stack_map_get_build_id_offset+0x98a/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1997 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1987 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5172 [inline] __schedule+0x1079/0x4a60 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:480 [inline] try_to_wake_up+0x9a1/0x1470 kernel/sched/core.c:4174 wake_up_process kernel/sched/core.c:4299 [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 --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&sighand->siglock); lock(&rq->__lock); lock(lock#10); *** DEADLOCK *** 2 locks held by syz.3.912/8422: #0: ffff8880b943e858 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 #1: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #1: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #1: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #1: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 0 PID: 8422 Comm: syz.3.912 Not tainted 6.10.0-syzkaller-04485-gfa5ef655615a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 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:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_start_locking+0x9c/0x620 mm/mmap_lock.c:230 __mmap_lock_trace_start_locking include/linux/mmap_lock.h:29 [inline] mmap_read_trylock include/linux/mmap_lock.h:162 [inline] stack_map_get_build_id_offset+0x98a/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1997 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1987 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5172 [inline] __schedule+0x1079/0x4a60 kernel/sched/core.c:6529 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:480 [inline] try_to_wake_up+0x9a1/0x1470 kernel/sched/core.c:4174 wake_up_process kernel/sched/core.c:4299 [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: 0033:0x7f7d94b75f19 Code: Unable to access opcode bytes at 0x7f7d94b75eef. RSP: 002b:00007f7d958e30f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f7d94d05f68 RCX: 00007f7d94b75f19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7d94d05f6c RBP: 00007f7d94d05f60 R08: 7fffffffffffffff R09: 00007f7d958e36c0 R10: 000000000000000c R11: 0000000000000246 R12: 00007f7d94d05f6c R13: 000000000000000b R14: 00007ffe36f7cb30 R15: 00007ffe36f7cc18