syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.158-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor141/3625 is trying to acquire lock:
ffff888012a00a28 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030

but task is already holding lock:
ffff8880b9b35bb8 (lock#8){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (lock#8){+.+.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       local_lock_acquire+0x29/0x170 include/linux/local_lock_internal.h:29
       __mmap_lock_do_trace_acquire_returned+0x7c/0x340 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+0x612/0x930 kernel/bpf/stackmap.c:185
       __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:496
       ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1490 [inline]
       bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1480
       0xffffffffa00309f2
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
       bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917
       trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x748/0xa30
       context_switch kernel/sched/core.c:5016 [inline]
       __schedule+0x1167/0x45b0 kernel/sched/core.c:6376
       schedule+0x11b/0x1f0 kernel/sched/core.c:6459
       exit_to_user_mode_loop+0x44/0x130 kernel/entry/common.c:169
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
       irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638

-> #1 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
       raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
       rq_lock kernel/sched/sched.h:1621 [inline]
       task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11480
       sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466
       copy_process+0x224a/0x3ef0 kernel/fork.c:2320
       kernel_clone+0x210/0x960 kernel/fork.c:2604
       kernel_thread+0x168/0x1e0 kernel/fork.c:2656
       rest_init+0x21/0x330 init/main.c:706
       start_kernel+0x48c/0x540 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #0 (&p->pi_lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __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+0xae/0x1300 kernel/sched/core.c:4030
       rcu_read_unlock_special+0x3aa/0x520 kernel/rcu/tree_plugin.h:650
       __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422
       rcu_read_unlock include/linux/rcupdate.h:771 [inline]
       put_memcg_path_buf+0xde/0x100 mm/mmap_lock.c:153
       __mmap_lock_do_trace_acquire_returned+0x12f/0x340 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]
       do_user_addr_fault arch/x86/mm/fault.c:1329 [inline]
       handle_page_fault arch/x86/mm/fault.c:1476 [inline]
       exc_page_fault+0x59c/0x740 arch/x86/mm/fault.c:1532
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568

other info that might help us debug this:

Chain exists of:
  &p->pi_lock --> &rq->__lock --> lock#8

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#8);
                               lock(&rq->__lock);
                               lock(lock#8);
  lock(&p->pi_lock);

 *** DEADLOCK ***

3 locks held by syz-executor141/3625:
 #0: ffff888078240f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888078240f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1329 [inline]
 #0: ffff888078240f28 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 #0: ffff888078240f28 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x740 arch/x86/mm/fault.c:1532
 #1: ffff8880b9b35bb8 (lock#8){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28
 #2: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 1 PID: 3625 Comm: syz-executor141 Not tainted 5.15.158-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+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __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+0xae/0x1300 kernel/sched/core.c:4030
 rcu_read_unlock_special+0x3aa/0x520 kernel/rcu/tree_plugin.h:650
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 put_memcg_path_buf+0xde/0x100 mm/mmap_lock.c:153
 __mmap_lock_do_trace_acquire_returned+0x12f/0x340 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]
 do_user_addr_fault arch/x86/mm/fault.c:1329 [inline]
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x59c/0x740 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0033:0x7fa09d3b8400
Code: 84 dd fe ff ff 4c 89 e7 e8 ed 90 00 00 e9 d0 fe ff ff 0f 1f 84 00 00 00 00 00 49 8b 06 48 89 45 00 48 85 c0 0f 85 85 00 00 00 <c6> 05 29 3d 0a 00 01 31 c0 87 05 f9 38 0a 00 83 f8 01 0f 8f 84 00
RSP: 002b:00007fffae47cf00 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00007fa09d45aad8
RBP: 00007fa09d459120 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa09d45bd08
R13: 0000000000000000 R14: 00007fa09d45bd20 R15: 00007fa09d3b1290
 </TASK>