syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.90-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor127/3551 is trying to acquire lock:
ffff8880771f40d8 (&sighand->siglock){....}-{2:2}, at: __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410

but task is already holding lock:
ffff8880b9835e90 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
ffff8880b9835e90 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (lock#9){+.+.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
       __mmap_lock_do_trace_acquire_returned+0x9d/0x670 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:137 [inline]
       stack_map_get_build_id_offset+0x99e/0x9c0 kernel/bpf/stackmap.c:144
       __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:452
       ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1877 [inline]
       bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1867
       bpf_prog_ec3b2eefa702d8d3+0x3a/0x3e
       bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
       __bpf_prog_run include/linux/filter.h:603 [inline]
       bpf_prog_run include/linux/filter.h:610 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
       bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312
       trace_tlb_flush+0x151/0x1a0 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x84a/0xc20
       context_switch kernel/sched/core.c:5230 [inline]
       __schedule+0x1140/0x4550 kernel/sched/core.c:6558
       preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
       preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
       preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
       __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
       _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
       spin_unlock include/linux/spinlock.h:391 [inline]
       __text_poke+0x81a/0x9a0 arch/x86/kernel/alternative.c:1216
       text_poke arch/x86/kernel/alternative.c:1240 [inline]
       text_poke_bp_batch+0x153/0x940 arch/x86/kernel/alternative.c:1531
       text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
       text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
       arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
       static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177
       static_key_enable+0x16/0x20 kernel/jump_label.c:190
       tracepoint_add_func+0x947/0x9d0 kernel/tracepoint.c:361
       tracepoint_probe_register_prio_may_exist+0x11e/0x190 kernel/tracepoint.c:482
       bpf_raw_tp_link_attach+0x456/0x6b0 kernel/bpf/syscall.c:3372
       bpf_raw_tracepoint_open+0x196/0x210 kernel/bpf/syscall.c:3399
       __sys_bpf+0x4a7/0x6c0 kernel/bpf/syscall.c:5047
       __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
       raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
       rq_lock kernel/sched/sched.h:1644 [inline]
       task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869
       sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686
       copy_process+0x2442/0x4060 kernel/fork.c:2384
       kernel_clone+0x222/0x920 kernel/fork.c:2682
       user_mode_thread+0x12e/0x190 kernel/fork.c:2758
       rest_init+0x23/0x300 init/main.c:699
       start_kernel+0x0/0x53f init/main.c:894
       start_kernel+0x496/0x53f init/main.c:1141
       secondary_startup_64_no_verify+0xcf/0xdb

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112
       signal_wake_up_state kernel/signal.c:780 [inline]
       signal_wake_up include/linux/sched/signal.h:457 [inline]
       complete_signal+0x796/0xbd0 kernel/signal.c:1074
       __send_signal_locked+0xb1a/0xdc0 kernel/signal.c:1194
       do_notify_parent+0xe2b/0x1100 kernel/signal.c:2120
       exit_notify kernel/exit.c:744 [inline]
       do_exit+0x172e/0x26a0 kernel/exit.c:889
       do_group_exit+0x202/0x2b0 kernel/exit.c:1019
       __do_sys_exit_group kernel/exit.c:1030 [inline]
       __se_sys_exit_group kernel/exit.c:1028 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sighand->siglock){....}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410
       lock_task_sighand include/linux/sched/signal.h:745 [inline]
       do_send_sig_info kernel/signal.c:1299 [inline]
       group_send_sig_info+0x26c/0x300 kernel/signal.c:1448
       bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:882
       ____bpf_send_signal_thread kernel/trace/bpf_trace.c:899 [inline]
       bpf_send_signal_thread+0x12/0x20 kernel/trace/bpf_trace.c:897
       bpf_prog_7bb747c56a8bcba8+0x15/0x1d
       bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
       __bpf_prog_run include/linux/filter.h:603 [inline]
       bpf_prog_run include/linux/filter.h:610 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
       bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
       trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline]
       __mmap_lock_do_trace_acquire_returned+0x5e3/0x670 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:137 [inline]
       get_mmap_lock_carefully mm/memory.c:5304 [inline]
       lock_mm_and_find_vma+0x219/0x2e0 mm/memory.c:5366
       do_user_addr_fault arch/x86/mm/fault.c:1343 [inline]
       handle_page_fault arch/x86/mm/fault.c:1462 [inline]
       exc_page_fault+0x169/0x660 arch/x86/mm/fault.c:1518
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

other info that might help us debug this:

Chain exists of:
  &sighand->siglock --> &rq->__lock --> lock#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#9);
                               lock(&rq->__lock);
                               lock(lock#9);
  lock(&sighand->siglock);

 *** DEADLOCK ***

5 locks held by syz-executor127/3551:
 #0: ffff888013ffbd58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888013ffbd58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5304 [inline]
 #0: ffff888013ffbd58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2e0 mm/memory.c:5366
 #1: ffff8880b9835e90 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
 #1: ffff8880b9835e90 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209
 #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #3: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x25/0x2d0 kernel/signal.c:1393

stack backtrace:
CPU: 0 PID: 3551 Comm: syz-executor127 Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 __lock_task_sighand+0x145/0x2d0 kernel/signal.c:1410
 lock_task_sighand include/linux/sched/signal.h:745 [inline]
 do_send_sig_info kernel/signal.c:1299 [inline]
 group_send_sig_info+0x26c/0x300 kernel/signal.c:1448
 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:882
 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:899 [inline]
 bpf_send_signal_thread+0x12/0x20 kernel/trace/bpf_trace.c:897
 bpf_prog_7bb747c56a8bcba8+0x15/0x1d
 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline]
 __mmap_lock_do_trace_acquire_returned+0x5e3/0x670 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:137 [inline]
 get_mmap_lock_carefully mm/memory.c:5304 [inline]
 lock_mm_and_find_vma+0x219/0x2e0 mm/memory.c:5366
 do_user_addr_fault arch/x86/mm/fault.c:1343 [inline]
 handle_page_fault arch/x86/mm/fault.c:1462 [inline]
 exc_page_fault+0x169/0x660 arch/x86/mm/fault.c:1518
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7fefcd90d79a
Code: 48 8d 3d ab a8 07 00 31 c0 e8 72 07 00 00 ba 12 00 00 00 bf 01 00 00 00 48 8d 35 ac a8 07 00 e8 3c 0a 03 00 31 c0 31 c9 31 d2 <89> 04 25 c4 00 00 20 31 f6 66 0f ef c0 bf 41 01 00 00 89 04 25 c8
RSP: 002b:00007ffd7d5a2890 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00007fefcd98803b RDI: 0000000000000001
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
R13: 00007ffd7d5a2aa8 R14: 00007ffd7d5a28b0 R15: 00007ffd7d5a28a0
 </TASK>