Re: [syzbot] [mm?] inconsistent lock state in __mmap_lock_do_trace_acquire_returned

From: Alexei Starovoitov
Date: Thu Apr 04 2024 - 18:22:38 EST

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In reply to: Andrew Morton: "Re: [syzbot] [mm?] inconsistent lock state in __mmap_lock_do_trace_acquire_returned"
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On Thu, Apr 4, 2024 at 2:31 PM Andrew Morton <akpm@linux-foundationorg> wrote:
>
> On Wed, 03 Apr 2024 17:21:24 -0700 syzbot <syzbot+76f802bc1dee8ba28a6e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > Hello,
>
> Thanks. I think this is due to BPF playing with mmap_lock from timer
> context. Cc added.

Looks like lockdep false positive.
bpf side is doing mmap_read_trylock for that very reason.

Adding Song, in case he sees something I don't.

> > 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@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > ================================
> > 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.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > If the report is already addressed, let syzbot know by replying with:
> > #syz fix: exact-commit-title
> >
> > If you want syzbot to run the reproducer, reply with:
> > #syz test: git://repo/address.git branch-or-commit-hash
> > If you attach or paste a git patch, syzbot will apply it before testing.
> >
> > If you want to overwrite report's subsystems, reply with:
> > #syz set subsystems: new-subsystem
> > (See the list of subsystem names on the web dashboard)
> >
> > If the report is a duplicate of another one, reply with:
> > #syz dup: exact-subject-of-another-report
> >
> > If you want to undo deduplication, reply with:
> > #syz undup
>

Next message: Kent Overstreet: "Re: [PATCH 1/1] mm: change inlined allocation helpers to account at the call site"
Previous message: Frank van der Linden: "Re: [PATCH 2/2] mm/hugetlb: pass correct order_per_bit to cma_declare_contiguous_nid"
In reply to: Andrew Morton: "Re: [syzbot] [mm?] inconsistent lock state in __mmap_lock_do_trace_acquire_returned"
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