syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.158-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor157/3509 is trying to acquire lock:
ffff8880237a65d8 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404

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:

-> #3 (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
       bpf_prog_ec3b2eefa702d8d3+0x3a/0x7cc
       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
       preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552
       preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577
       preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
       __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
       spin_unlock include/linux/spinlock.h:403 [inline]
       __text_poke+0x871/0x9e0 arch/x86/kernel/alternative.c:1154
       text_poke arch/x86/kernel/alternative.c:1178 [inline]
       text_poke_bp_batch+0x14c/0x930 arch/x86/kernel/alternative.c:1404
       text_poke_flush arch/x86/kernel/alternative.c:1598 [inline]
       text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1605
       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_tracepoint_open+0x65a/0x750 kernel/bpf/syscall.c:3113
       __sys_bpf+0x468/0x670 kernel/bpf/syscall.c:4693
       __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
       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

-> #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: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

-> #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
       signal_wake_up_state kernel/signal.c:770 [inline]
       signal_wake_up include/linux/sched/signal.h:421 [inline]
       complete_signal+0x5a0/0x9a0 kernel/signal.c:1062
       __send_signal+0xaaf/0xd40 kernel/signal.c:1182
       do_notify_parent+0xc1e/0xf00 kernel/signal.c:2113
       exit_notify kernel/exit.c:729 [inline]
       do_exit+0x1464/0x2480 kernel/exit.c:892
       do_group_exit+0x144/0x310 kernel/exit.c:994
       __do_sys_exit_group kernel/exit.c:1005 [inline]
       __se_sys_exit_group kernel/exit.c:1003 [inline]
       __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003
       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

-> #0 (&sighand->siglock){-...}-{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
       __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404
       lock_task_sighand include/linux/sched/signal.h:704 [inline]
       do_send_sig_info kernel/signal.c:1293 [inline]
       group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442
       bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824
       ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline]
       bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827
       bpf_prog_da8cbe553dc44a71+0x1a/0xfb4
       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_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919
       trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline]
       __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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
       __put_user_nocheck_4+0x3/0x11
       schedule_tail+0x92/0xb0 kernel/sched/core.c:4970
       ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:285

other info that might help us debug this:

Chain exists of:
  &sighand->siglock --> &rq->__lock --> lock#8

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#8);
                               lock(&rq->__lock);
                               lock(lock#8);
  lock(&sighand->siglock);

 *** DEADLOCK ***

5 locks held by syz-executor157/3509:
 #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1329 [inline]
 #0: ffff888023a69628 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 #0: ffff888023a69628 (&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
 #3: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #4: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 1 PID: 3509 Comm: syz-executor157 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
 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404
 lock_task_sighand include/linux/sched/signal.h:704 [inline]
 do_send_sig_info kernel/signal.c:1293 [inline]
 group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442
 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824
 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline]
 bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827
 bpf_prog_da8cbe553dc44a71+0x1a/0xfb4
 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_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919
 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline]
 __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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: 0010:__put_user_nocheck_4+0x3/0x11
Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 0f 1f 44 00 00 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f
RSP: 0018:ffffc90002d37f28 EFLAGS: 00050297
RAX: 0000000000000db5 RBX: 00007fffffffeffd RCX: 0000555556914650
RDX: 0000000000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f600
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1bc8c56
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807993c220
R13: 0000000000000000 R14: ffff88807993bb80 R15: dffffc0000000000
 schedule_tail+0x92/0xb0 kernel/sched/core.c:4970
 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:285
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	48 39 d9             	cmp    %rbx,%rcx
   5:	73 54                	jae    0x5b
   7:	0f 01 cb             	stac
   a:	66 89 01             	mov    %ax,(%rcx)
   d:	31 c9                	xor    %ecx,%ecx
   f:	0f 01 ca             	clac
  12:	c3                   	ret
  13:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  18:	48 bb fd ef ff ff ff 	movabs $0x7fffffffeffd,%rbx
  1f:	7f 00 00
  22:	48 39 d9             	cmp    %rbx,%rcx
  25:	73 34                	jae    0x5b
  27:	0f 01 cb             	stac
* 2a:	89 01                	mov    %eax,(%rcx) <-- trapping instruction
  2c:	31 c9                	xor    %ecx,%ecx
  2e:	0f 01 ca             	clac
  31:	c3                   	ret
  32:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
  38:	48                   	rex.W
  39:	bb f9 ef ff ff       	mov    $0xffffeff9,%ebx
  3e:	ff                   	(bad)
  3f:	7f                   	.byte 0x7f