syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.164-syzkaller #0 Not tainted
------------------------------------------------------
dhcpcd/3238 is trying to acquire lock:
ffff8880b9a35bb8 (lock#8){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28

but task is already holding lock:
ffff8880b9a3a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&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:11495
       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

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       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]
       get_mem_cgroup_from_mm+0x179/0x260 mm/memcontrol.c:992
       get_mm_memcg_path+0x1b/0x550 mm/mmap_lock.c:202
       __mmap_lock_do_trace_acquire_returned+0x84/0x340 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:1298 [inline]
       handle_page_fault arch/x86/mm/fault.c:1445 [inline]
       exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
       __put_user_nocheck_8+0x3/0x21
       clear_rseq_cs kernel/rseq.c:220 [inline]
       rseq_ip_fixup kernel/rseq.c:254 [inline]
       __rseq_handle_notify_resume+0x605/0x1250 kernel/rseq.c:292
       rseq_handle_notify_resume include/linux/sched.h:2204 [inline]
       tracehook_notify_resume include/linux/tracehook.h:201 [inline]
       exit_to_user_mode_loop+0xdc/0x130 kernel/entry/common.c:181
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
       __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
       syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
       do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (lock#8){+.+.}-{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
       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
       bpf_prog_ec3b2eefa702d8d3+0x3a/0xcf4
       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
       schedule_hrtimeout_range_clock+0x2b3/0x4a0 kernel/time/hrtimer.c:2308
       poll_schedule_timeout+0x10c/0x150 fs/select.c:243
       do_poll fs/select.c:964 [inline]
       do_sys_poll+0xd61/0x11f0 fs/select.c:1014
       __do_sys_ppoll fs/select.c:1120 [inline]
       __se_sys_ppoll+0x29c/0x330 fs/select.c:1100
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by dhcpcd/3238:
 #0: ffff8880b9a3a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #2: ffff888019a5b228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #2: ffff888019a5b228 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x23e/0x930 kernel/bpf/stackmap.c:185

stack backtrace:
CPU: 0 PID: 3238 Comm: dhcpcd Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
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
 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
 bpf_prog_ec3b2eefa702d8d3+0x3a/0xcf4
 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
 schedule_hrtimeout_range_clock+0x2b3/0x4a0 kernel/time/hrtimer.c:2308
 poll_schedule_timeout+0x10c/0x150 fs/select.c:243
 do_poll fs/select.c:964 [inline]
 do_sys_poll+0xd61/0x11f0 fs/select.c:1014
 __do_sys_ppoll fs/select.c:1120 [inline]
 __se_sys_ppoll+0x29c/0x330 fs/select.c:1100
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbfd01b4ad5
Code: Unable to access opcode bytes at RIP 0x7fbfd01b4aab.
RSP: 002b:00007fff49517ca0 EFLAGS: 00000246 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 000055756b7cae20 RCX: 00007fbfd01b4ad5
RDX: 00007fff49517cc0 RSI: 0000000000000004 RDI: 000055756b7d5b60
RBP: 00007fff49517ff0 R08: 0000000000000008 R09: 0000000000000010
R10: 00007fff49517ff0 R11: 0000000000000246 R12: 00007fff49517ce8
R13: 0000557569a88610 R14: 0000000000000000 R15: 0000000000000000
 </TASK>