syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.90-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor237/3548 is trying to acquire lock:
ffff8880b9935e90 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
ffff8880b9935e90 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237

but task is already holding lock:
ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&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

-> #2 (&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

-> #1 (&sighand->siglock){-...}-{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
       __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
       0xffffffffa00007e1
       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
       strncpy_from_user+0x159/0x360 lib/strncpy_from_user.c:139
       strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline]
       bpf_prog_load+0x188/0x1bb0 kernel/bpf/syscall.c:2515
       __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5005
       __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

-> #0 (lock#9){+.+.}-{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
       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_irq+0xf7/0x1c0 kernel/sched/core.c:6870
       irqentry_exit+0x53/0x80 kernel/entry/common.c:439
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
       acct_collect+0x205/0x7f0 kernel/acct.c:566
       do_exit+0x984/0x26a0 kernel/exit.c:848
       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

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

4 locks held by syz-executor237/3548:
 #0: ffff88802a03f1d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
 #0: ffff88802a03f1d8 (&mm->mmap_lock){++++}-{3:3}, at: acct_collect+0x1bd/0x7f0 kernel/acct.c:564
 #1: ffff8880b993aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #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: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312
 #3: ffff88802a03f1d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #3: ffff88802a03f1d8 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x232/0x9c0 kernel/bpf/stackmap.c:144

stack backtrace:
CPU: 1 PID: 3548 Comm: syz-executor237 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
 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_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:acct_collect+0x205/0x7f0 kernel/acct.c:566
Code: 48 85 c0 0f 84 cb 00 00 00 49 89 c5 45 31 e4 49 8d 7d 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 3f fd 61 00 4d 8b 7d 08 <4c> 89 e8 48 c1 e8 03 42 80 3c 30 00 74 08 4c 89 ef e8 25 fd 61 00
RSP: 0018:ffffc90003adfbe0 EFLAGS: 00000246
RAX: 1ffff110044fdc01 RBX: ffffc90003adfc80 RCX: ffff88802978bb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880227ee008
RBP: ffffc90003adfd30 R08: ffffffff8a80e143 R09: ffffffff8a80dc72
R10: 0000000000000003 R11: ffff88802978bb80 R12: 00000000010a9000
R13: ffff8880227ee000 R14: dffffc0000000000 R15: 00007f53baacb000
 do_exit+0x984/0x26a0 kernel/exit.c:848
 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
RIP: 0033:0x7f53baa56989
Code: Unable to access opcode bytes at 0x7f53baa5695f.
RSP: 002b:00007ffc66fdb108 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f53baa56989
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f53baad12b0 R08: ffffffffffffffb8 R09: 00007ffc66fdb17c
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f53baad12b0
R13: 0000000000000000 R14: 00007f53baad1d00 R15: 00007f53baa276d0
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 85 c0             	test   %rax,%rax
   3:	0f 84 cb 00 00 00    	je     0xd4
   9:	49 89 c5             	mov    %rax,%r13
   c:	45 31 e4             	xor    %r12d,%r12d
   f:	49 8d 7d 08          	lea    0x8(%r13),%rdi
  13:	48 89 f8             	mov    %rdi,%rax
  16:	48 c1 e8 03          	shr    $0x3,%rax
  1a:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1)
  1f:	74 05                	je     0x26
  21:	e8 3f fd 61 00       	call   0x61fd65
  26:	4d 8b 7d 08          	mov    0x8(%r13),%r15
* 2a:	4c 89 e8             	mov    %r13,%rax <-- trapping instruction
  2d:	48 c1 e8 03          	shr    $0x3,%rax
  31:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1)
  36:	74 08                	je     0x40
  38:	4c 89 ef             	mov    %r13,%rdi
  3b:	e8 25 fd 61 00       	call   0x61fd65