From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BB43C433EF for ; Tue, 7 Dec 2021 13:58:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237456AbhLGOCA (ORCPT ); Tue, 7 Dec 2021 09:02:00 -0500 Received: from mail-il1-f199.google.com ([209.85.166.199]:51736 "EHLO mail-il1-f199.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237442AbhLGOB7 (ORCPT ); Tue, 7 Dec 2021 09:01:59 -0500 Received: by mail-il1-f199.google.com with SMTP id l2-20020a056e021aa200b002a281027bb8so11917298ilv.18 for ; Tue, 07 Dec 2021 05:58:29 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=vyYT5lQSN9Sd07tZWpU3Ums+gflAZlF8eMmG8VRlrwU=; b=6b6V8JrJ/0s3VXXS3G0YBB8zd0fCjeunZp7juuiiAOhOHlP8IQiyhOtiV9ZjBWvDV9 8jIAVppF07Ndm0cRbszJ3FPtKeksTAijuYVG3h0Eft+GpQSyj9kEX9SL/CaK4t8WqOdT P0ryHM4CJqfk8FhcjsT9xFFM+ZQ6SHd7e8GlNKGSwkGpsj/X/EXx3v89SCNNXNC7yp5b usfRZ8IXyRUTFFaSzdPV8q992IqYUQkw5RNPXfp5rol4fGB2Q8S9i9OhTQ8kT4bGrriD SvUxZ7NHXfTt35OvhttchpSBW+w+NEC5SZ8agAcOkz6DXOGbgiBbN/abR9f6awW/KbV7 fnKA== X-Gm-Message-State: AOAM5321p3djHMgPAEzu5X2UmRIBaQMhIxJETgCw6gUILJ5JhDMKJkDP xXjR/DrYUPdkrMe+uOeMcP/s1kqf2iKx2VTi2Mv0+HyY+zXu X-Google-Smtp-Source: ABdhPJwq6tpUBzOzsC5a8oLyelPmZ6yFy3KVG3mvshYWc3YUKRwnnyTlzhpa2+wW3ND6VGNGDJPe8XwqgB4tgTAHpvLHTFdRoIES MIME-Version: 1.0 X-Received: by 2002:a05:6e02:484:: with SMTP id b4mr39006206ils.173.1638885509424; Tue, 07 Dec 2021 05:58:29 -0800 (PST) Date: Tue, 07 Dec 2021 05:58:29 -0800 In-Reply-To: <000000000000a636fc05cee1e95b@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009dee1a05d28ec4a1@google.com> Subject: Re: [syzbot] INFO: rcu detected stall in sys_bpf (5) From: syzbot To: fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, mingo@redhat.com, netdev@vger.kernel.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: d5284dedccdb libbpf: Add doc comments in libbpf.h git tree: bpf-next console output: https://syzkaller.appspot.com/x/log.txt?x=157d0e55b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=a262045c4c15a9e0 dashboard link: https://syzkaller.appspot.com/bug?extid=7caa651776c38f7fed6c compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=132f9da9b00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11e749a9b00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7caa651776c38f7fed6c@syzkaller.appspotmail.com hrtimer: interrupt took 34034 ns rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (11003 ticks this GP) idle=21b/1/0x4000000000000000 softirq=8763/8765 fqs=5250 (t=10502 jiffies g=11285 q=14) NMI backtrace for cpu 0 CPU: 0 PID: 6526 Comm: syz-executor734 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:htab_unlock_bucket kernel/bpf/hashtab.c:192 [inline] RIP: 0010:htab_lru_map_update_elem+0x463/0x8c0 kernel/bpf/hashtab.c:1178 Code: 04 00 00 49 89 6d 08 e8 6b 8b ea ff 48 8b 74 24 28 48 b8 22 01 00 00 00 00 ad de 48 8b 7c 24 10 49 89 44 24 08 e8 2d f3 b0 07 <48> c7 c7 20 d4 93 89 e8 e1 23 ae 07 48 8b 54 24 18 48 b8 00 00 00 RSP: 0018:ffffc90000cd7a88 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88807efdc800 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8880218f2c00 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e0a58 R11: 0000000000000000 R12: ffff8880218f2c40 R13: 000000000000000b R14: 0000000000000005 R15: 0000000000000001 bpf_map_update_value.isra.0+0x2e8/0x910 kernel/bpf/syscall.c:207 generic_map_update_batch+0x3f2/0x5b0 kernel/bpf/syscall.c:1396 bpf_map_do_batch+0x3d5/0x510 kernel/bpf/syscall.c:4207 __sys_bpf+0x2761/0x5f10 kernel/bpf/syscall.c:4682 __do_sys_bpf kernel/bpf/syscall.c:4722 [inline] __se_sys_bpf kernel/bpf/syscall.c:4720 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4720 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa79bb49f29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdbbb21d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa79bb49f29 RDX: 0000000000000038 RSI: 0000000020000480 RDI: 000000000000001a RBP: 0000000000000000 R08: 00007ffdbbb21f28 R09: 00007ffdbbb21f28 R10: 00007ffdbbb21f28 R11: 0000000000000246 R12: 00007fa79bb0d7b0 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 04 00 add $0x0,%al 2: 00 49 89 add %cl,-0x77(%rcx) 5: 6d insl (%dx),%es:(%rdi) 6: 08 e8 or %ch,%al 8: 6b 8b ea ff 48 8b 74 imul $0x74,-0x74b70016(%rbx),%ecx f: 24 28 and $0x28,%al 11: 48 b8 22 01 00 00 00 movabs $0xdead000000000122,%rax 18: 00 ad de 1b: 48 8b 7c 24 10 mov 0x10(%rsp),%rdi 20: 49 89 44 24 08 mov %rax,0x8(%r12) 25: e8 2d f3 b0 07 callq 0x7b0f357 * 2a: 48 c7 c7 20 d4 93 89 mov $0xffffffff8993d420,%rdi <-- trapping instruction 31: e8 e1 23 ae 07 callq 0x7ae2417 36: 48 8b 54 24 18 mov 0x18(%rsp),%rdx 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)