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Date: Thu, 4 Apr 2024 14:31:42 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: syzbot <syzbot+76f802bc1dee8ba28a6e@syzkaller.appspotmail.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
 syzkaller-bugs@googlegroups.com, bpf@vger.kernel.org
Subject: Re: [syzbot] [mm?] inconsistent lock state in
 __mmap_lock_do_trace_acquire_returned
Message-Id: <20240404143142.9e99f7127703892cb3166d64@linux-foundation.org>
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On Wed, 03 Apr 2024 17:21:24 -0700 syzbot <syzbot+76f802bc1dee8ba28a6e@syzkaller.appspotmail.com> wrote:

> Hello,

Thanks.  I think this is due to BPF playing with mmap_lock from timer
context.  Cc added.

> syzbot found the following issue on:
> 
> HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=132e732d180000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=aef2a55903e5791c
> dashboard link: https://syzkaller.appspot.com/bug?extid=76f802bc1dee8ba28a6e
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16d61b76180000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=166ee109180000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/089e25869df5/disk-fe46a7dd.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/423b1787914f/vmlinux-fe46a7dd.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/4c043e30c07d/bzImage-fe46a7dd.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+76f802bc1dee8ba28a6e@syzkaller.appspotmail.com
> 
> ================================
> WARNING: inconsistent lock state
> 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
> --------------------------------
> inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> syz-executor244/5087 [HC0[0]:SC1[1]:HE0:SE0] takes:
> ffff8880b9538780 (lock#9){+.?.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
> ffff8880b9538780 (lock#9){+.?.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x760 mm/mmap_lock.c:237
> {SOFTIRQ-ON-W} state was registered at:
>   lock_acquire kernel/locking/lockdep.c:5754 [inline]
>   lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
>   local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
>   __mmap_lock_do_trace_acquire_returned+0x97/0x760 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.constprop.0+0x7d7/0xa10 mm/process_vm_access.c:216
>   process_vm_rw+0x301/0x360 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+0xe2/0x1c0 mm/process_vm_access.c:292
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
>   entry_SYSCALL_64_after_hwframe+0x6d/0x75
> irq event stamp: 997
> hardirqs last  enabled at (996): [<ffffffff8ad62d96>] __do_softirq+0x1d6/0x8de kernel/softirq.c:538
> hardirqs last disabled at (997): [<ffffffff8ad5ff95>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline]
> hardirqs last disabled at (997): [<ffffffff8ad5ff95>] _raw_spin_lock_irq+0x45/0x50 kernel/locking/spinlock.c:170
> softirqs last  enabled at (896): [<ffffffff819e467f>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
> softirqs last  enabled at (896): [<ffffffff819e467f>] bpf_link_settle kernel/bpf/syscall.c:3181 [inline]
> softirqs last  enabled at (896): [<ffffffff819e467f>] bpf_raw_tp_link_attach+0x35f/0x610 kernel/bpf/syscall.c:3842
> softirqs last disabled at (995): [<ffffffff8151a149>] invoke_softirq kernel/softirq.c:428 [inline]
> softirqs last disabled at (995): [<ffffffff8151a149>] __irq_exit_rcu kernel/softirq.c:633 [inline]
> softirqs last disabled at (995): [<ffffffff8151a149>] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
> 
> other info that might help us debug this:
>  Possible unsafe locking scenario:
> 
>        CPU0
>        ----
>   lock(lock#9);
>   <Interrupt>
>     lock(lock#9);
> 
>  *** DEADLOCK ***
> 
> 6 locks held by syz-executor244/5087:
>  #0: ffff88802247b1e8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_cleanup_begin kernel/futex/core.c:1091 [inline]
>  #0: ffff88802247b1e8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_exit_release+0x2a/0x220 kernel/futex/core.c:1143
>  #1: ffffc90000a08cb0 (&(&ipvs->defense_work)->timer){..-.}-{0:0}, at: call_timer_fn+0x11a/0x5b0 kernel/time/timer.c:1789
>  #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
>  #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
>  #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: __queue_work+0xf2/0x1170 kernel/workqueue.c:2324
>  #3: ffff8880b953d5d8 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x39e/0x1170 kernel/workqueue.c:2360
>  #4: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
>  #4: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
>  #4: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
>  #4: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf8/0x440 kernel/trace/bpf_trace.c:2421
>  #5: ffff88807965b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
>  #5: ffff88807965b120 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x1e8/0x7d0 kernel/bpf/stackmap.c:141
> 
> stack backtrace:
> CPU: 1 PID: 5087 Comm: syz-executor244 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
> Call Trace:
>  <IRQ>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
>  print_usage_bug kernel/locking/lockdep.c:3971 [inline]
>  valid_state kernel/locking/lockdep.c:4013 [inline]
>  mark_lock_irq kernel/locking/lockdep.c:4216 [inline]
>  mark_lock+0x923/0xc60 kernel/locking/lockdep.c:4678
>  mark_usage kernel/locking/lockdep.c:4567 [inline]
>  __lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091
>  lock_acquire kernel/locking/lockdep.c:5754 [inline]
>  lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
>  local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
>  __mmap_lock_do_trace_acquire_returned+0x97/0x760 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+0x5df/0x7d0 kernel/bpf/stackmap.c:141
>  __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449
>  ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline]
>  bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1975
>  ___bpf_prog_run+0x3e51/0xae80 kernel/bpf/core.c:1997
>  __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236
>  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_run3+0x167/0x440 kernel/trace/bpf_trace.c:2421
>  __bpf_trace_workqueue_queue_work+0x101/0x140 include/trace/events/workqueue.h:23
>  __traceiter_workqueue_queue_work+0x6c/0xc0 include/trace/events/workqueue.h:23
>  trace_workqueue_queue_work include/trace/events/workqueue.h:23 [inline]
>  __queue_work+0x627/0x1170 kernel/workqueue.c:2382
>  call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792
>  expire_timers kernel/time/timer.c:1838 [inline]
>  __run_timers+0x567/0xab0 kernel/time/timer.c:2408
>  __run_timer_base kernel/time/timer.c:2419 [inline]
>  __run_timer_base kernel/time/timer.c:2412 [inline]
>  run_timer_base+0x111/0x190 kernel/time/timer.c:2428
>  run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438
>  __do_softirq+0x218/0x8de kernel/softirq.c:554
>  invoke_softirq kernel/softirq.c:428 [inline]
>  __irq_exit_rcu kernel/softirq.c:633 [inline]
>  irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
>  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
>  sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
>  </IRQ>
>  <TASK>
>  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
> RIP: 0010:lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722
> Code: c1 05 ea 37 97 7e 83 f8 01 0f 85 c8 02 00 00 9c 58 f6 c4 02 0f 85 b3 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
> RSP: 0018:ffffc90003457ba0 EFLAGS: 00000206
> RAX: dffffc0000000000 RBX: 1ffff9200068af76 RCX: ffffffff816a5d5e
> RDX: 0000000000000001 RSI: ffffffff8b0cba40 RDI: ffffffff8b6e88a0
> RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff27b4e38
> R10: ffffffff93da71c7 R11: 0000000000000000 R12: 0000000000000001
> R13: 0000000000000000 R14: ffff88802247b1e8 R15: 0000000000000000
>  __mutex_lock_common kernel/locking/mutex.c:608 [inline]
>  __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
>  futex_cleanup_begin kernel/futex/core.c:1091 [inline]
>  futex_exit_release+0x2a/0x220 kernel/futex/core.c:1143
>  exit_mm_release+0x19/0x30 kernel/fork.c:1652
>  exit_mm kernel/exit.c:542 [inline]
>  do_exit+0x865/0x2be0 kernel/exit.c:865
>  do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
>  __do_sys_exit_group kernel/exit.c:1038 [inline]
>  __se_sys_exit_group kernel/exit.c:1036 [inline]
>  __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x6d/0x75
> RIP: 0033:0x7f44f7223a79
> Code: 90 49 c7 c0 b8 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00
> RSP: 002b:00007ffd5c6574d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f44f7223a79
> RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
> RBP: 00007f44f729e2b0 R08: ffffffffffffffb8 R09: 00000000000f4240
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f44f729e2b0
> R13: 0000000000000000 R14: 00007f44f729ed20 R15: 00007f44f71f4700
>  </TASK>
> ----------------
> Code disassembly (best guess):
>    0:	c1 05 ea 37 97 7e 83 	roll   $0x83,0x7e9737ea(%rip)        # 0x7e9737f1
>    7:	f8                   	clc
>    8:	01 0f                	add    %ecx,(%rdi)
>    a:	85 c8                	test   %ecx,%eax
>    c:	02 00                	add    (%rax),%al
>    e:	00 9c 58 f6 c4 02 0f 	add    %bl,0xf02c4f6(%rax,%rbx,2)
>   15:	85 b3 02 00 00 48    	test   %esi,0x48000002(%rbx)
>   1b:	85 ed                	test   %ebp,%ebp
>   1d:	74 01                	je     0x20
>   1f:	fb                   	sti
>   20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
>   27:	fc ff df
> * 2a:	48 01 c3             	add    %rax,%rbx <-- trapping instruction
>   2d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
>   34:	48 c7 43 08 00 00 00 	movq   $0x0,0x8(%rbx)
>   3b:	00
>   3c:	48                   	rex.W
>   3d:	8b                   	.byte 0x8b
>   3e:	84                   	.byte 0x84
>   3f:	24                   	.byte 0x24
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
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