syzbot

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00185-g3e9bc0472b91 #0 Not tainted
------------------------------------------------------
strace-static-x/5082 is trying to acquire lock:
ffff8880172b4610 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
ffff8880172b4610 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262

but task is already holding lock:
ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (lock#9){+.+.}-{2:2}:
       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:166 [inline]
       stack_map_get_build_id_offset+0x9b2/0x9d0 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:1985 [inline]
       bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975
       0xffffffffa0003932
       bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
       __bpf_prog_run include/linux/filter.h:657 [inline]
       bpf_prog_run include/linux/filter.h:664 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
       bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
       trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x7cb/0xae0
       context_switch kernel/sched/core.c:5393 [inline]
       __schedule+0x1066/0x4a50 kernel/sched/core.c:6746
       __schedule_loop kernel/sched/core.c:6823 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6838
       ptrace_stop+0x5b4/0x940 kernel/signal.c:2358
       ptrace_do_notify kernel/signal.c:2395 [inline]
       ptrace_notify+0x255/0x380 kernel/signal.c:2407
       ptrace_report_syscall include/linux/ptrace.h:415 [inline]
       ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
       syscall_exit_work+0xc6/0x190 kernel/entry/common.c:173
       syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
       syscall_exit_to_user_mode+0x273/0x370 kernel/entry/common.c:218
       do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
       raw_spin_rq_lock kernel/sched/sched.h:1387 [inline]
       rq_lock kernel/sched/sched.h:1701 [inline]
       task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12635
       sched_cgroup_fork+0x37c/0x410 kernel/sched/core.c:4845
       copy_process+0x2217/0x3df0 kernel/fork.c:2499
       kernel_clone+0x226/0x8f0 kernel/fork.c:2797
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2875
       rest_init+0x23/0x300 init/main.c:704
       start_kernel+0x47a/0x500 init/main.c:1081
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #0 (&p->pi_lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       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
       rcu_read_unlock_special+0x3db/0x550 kernel/rcu/tree_plugin.h:655
       __rcu_read_unlock+0xa1/0x110 kernel/rcu/tree_plugin.h:426
       rcu_read_unlock include/linux/rcupdate.h:813 [inline]
       put_memcg_path_buf+0xde/0x110 mm/mmap_lock.c:153
       __mmap_lock_do_trace_acquire_returned+0x1f9/0x630 mm/mmap_lock.c:237
       __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
       mmap_read_lock include/linux/mmap_lock.h:147 [inline]
       process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
       process_vm_rw_core mm/process_vm_access.c:216 [inline]
       process_vm_rw+0xa46/0xcf0 mm/process_vm_access.c:284
       __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline]
       __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline]
       __x64_sys_process_vm_readv+0xe0/0x100 mm/process_vm_access.c:292
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &p->pi_lock --> &rq->__lock --> lock#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#9);
                               lock(&rq->__lock);
                               lock(lock#9);
  lock(&p->pi_lock);

 *** DEADLOCK ***

3 locks held by strace-static-x/5082:
 #0: ffff88802c4594a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline]
 #0: ffff88802c4594a0 (&mm->mmap_lock){++++}-{3:3}, at: process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
 #0: ffff88802c4594a0 (&mm->mmap_lock){++++}-{3:3}, at: process_vm_rw_core mm/process_vm_access.c:216 [inline]
 #0: ffff88802c4594a0 (&mm->mmap_lock){++++}-{3:3}, at: process_vm_rw+0x6e9/0xcf0 mm/process_vm_access.c:284
 #1: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
 #1: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237
 #2: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #2: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #2: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline]
 #2: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209

stack backtrace:
CPU: 0 PID: 5082 Comm: strace-static-x Not tainted 6.9.0-rc5-syzkaller-00185-g3e9bc0472b91 #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+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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 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
 rcu_read_unlock_special+0x3db/0x550 kernel/rcu/tree_plugin.h:655
 __rcu_read_unlock+0xa1/0x110 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:813 [inline]
 put_memcg_path_buf+0xde/0x110 mm/mmap_lock.c:153
 __mmap_lock_do_trace_acquire_returned+0x1f9/0x630 mm/mmap_lock.c:237
 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
 mmap_read_lock include/linux/mmap_lock.h:147 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0xa46/0xcf0 mm/process_vm_access.c:284
 __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline]
 __x64_sys_process_vm_readv+0xe0/0x100 mm/process_vm_access.c:292
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x4eacda
Code: 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 38 12 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 36 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7
RSP: 002b:00007ffc2fa6b728 EFLAGS: 00000246 ORIG_RAX: 0000000000000136
RAX: ffffffffffffffda RBX: 00007f348c1bb000 RCX: 00000000004eacda
RDX: 0000000000000001 RSI: 00007ffc2fa6b750 RDI: 00000000000016c5
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 00007ffc2fa6b760 R11: 0000000000000246 R12: 00007f348c1bb022
R13: 00007ffc2fa6b810 R14: 0000000000001000 R15: 0000000000000fde
 </TASK>