From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B51DD3BD653 for ; Sun, 27 Sep 2026 09:01:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790499690; cv=none; b=tr0zsTEyKd2/Lv6JajjD3p+BHVwGq4HeCUInvAspJzW3guFmwO4jEVkz1EZwD1pI1q5HoLMkLH8Ie/0gfeD+Fl9YHbGjBKruXHp/MfZOBQ8GkG69BBlEaCNCcANmvqJEVkYqo4+Q8x0BDj1iE5hj51/bnIlLJ3a3lUKXOPy4i80= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790499690; c=relaxed/simple; bh=9JuhtbENpsjbZXxQ3saypGflidZ0aCxl9sYtCNnQAi0=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=C4ou6/PvqhSiGyDcc4qf3iQVbDauK8v6J9a5XzWVsa1JatVKs2L914TSE1zrKlukyeV1U6N2zIzhP8rCzZUWZF5TSJlhxij61xV5XM89GEavrd1BVr9iE8FsXSAda0AEENa9Oa0xYCg4DB+PJbGpEy4TMgMpsi1tj00aQglaANk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f197.google.com with SMTP id 5614622812f47-4b38ea4c6acso2311620b6e.1 for ; Sun, 27 Sep 2026 02:01:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790499687; x=1791104487; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=WQzw/YpLSMoSCiIwI7FbfAM4xPr8HwMrq7VMglE0Y1E=; b=ifV2w1oFtD4rJDv6udRCahJw5N4J0rrsYqgwkl1K88eVEVv3fhGK+W7IZOu/8ZcRGT pYdzotNTzqwsJuvHIpkVokGCUUuMc4LyY1mgOcuk8kpm3zwUrj4BHOyFREyQHEoq7Vo4 vSWWu+RfHXPrUV+T8aeNZ/kfRdKk854zTKYQfgO4jngvcsw4WzY4ZjljoSyropXpKuwt YIyAEyyPzxzh3hNrh5f5PhutMwlJ3e4KKLW/xhIrA0erqqbZH7oqfrF333+evPGtE67Q URqz8qLd/LS66lui7meCPeiGi17P8o14ZJotdDvowRn2sQ0+lbtvz1FLf4+mZ9GCMCni OULA== X-Forwarded-Encrypted: i=1; AKwUvByZrUGV66B/G1k9FxDPZYzD2nmRBEl8uYnBT60eTAGLkGw13LaU7mSFOx1quCZgoXB2LE9tp7xiuqNS5SI=@vger.kernel.org X-Gm-Message-State: AFuF++mZS7oyELnlf3tI2asuW4eOw4HW2/Kq7IoEL4BWzjkBUgjNnjMv 3hdok6cQK+FBm+AVBhY1CkQGaFEzse1ii8fTeWIZL7LfqctNX2t+YyxVzHv634Up4Ipc8K3xemd NRtb1hmFJwuxsZS7wa0pdJ6HBZlJuMZs8lhQoTp/0s7k8O69RL7ZUyAVQTlg= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:15a0:b0:4d6:93e2:5bc8 with SMTP id 5614622812f47-4d72d6603f8mr12738235b6e.68.1790499687338; Sun, 27 Sep 2026 02:01:27 -0700 (PDT) Date: Sun, 27 Sep 2026 02:01:27 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ab8db67.dc2998a4.2261f5.0064.GAE@google.com> Subject: [syzbot] [net?] INFO: rcu detected stall in advance_sched (2) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, jhs@mojatatu.com, jiri@resnulli.us, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, vinicius.gomes@intel.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: aa98230e410f Merge tag 'vfs-7.3-rc5.fixes' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17a3e2c9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=718e346eb0b8f38 dashboard link: https://syzkaller.appspot.com/bug?extid=e0fa723f5960605c7ddb compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d8db131abdba/disk-aa98230e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/58014231ef21/vmlinux-aa98230e.xz kernel image: https://storage.googleapis.com/syzbot-assets/97cab136e4af/bzImage-aa98230e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e0fa723f5960605c7ddb@syzkaller.appspotmail.com rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29 rcu: (detected by 1, t=10592 jiffies, g=56017, q=13328 ncpus=2) task:ktimers/1 state:R running task stack:24168 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080010 Call Trace: sched_show_task+0x4aa/0x5f0 kernel/sched/core.c:8250 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall+0xfbf/0x1350 kernel/rcu/tree_stall.h:683 check_cpu_stall kernel/rcu/tree_stall.h:860 [inline] rcu_pending kernel/rcu/tree.c:3744 [inline] rcu_sched_clock_irq+0x9fe/0x10e0 kernel/rcu/tree.c:2749 update_process_times+0x234/0x2d0 kernel/time/timer.c:2475 tick_sched_handle kernel/time/tick-sched.c:296 [inline] tick_nohz_handler+0x38f/0x6b0 kernel/time/tick-sched.c:317 __run_hrtimer kernel/time/hrtimer.c:2074 [inline] __hrtimer_run_queues+0x3a0/0xaf0 kernel/time/hrtimer.c:2131 hrtimer_interrupt+0x4c2/0xa80 kernel/time/hrtimer.c:2250 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:6021 Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 c4 bd 4d 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4b d1 03 00 cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc90000a3fab8 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8dae029b RDI: ffffffff8bcc4a80 RBP: 00000000ffffffff R08: 0000000000000100 R09: 0000000000000100 R10: dffffc0000000000 R11: fffffbfff1f64530 R12: 0000000000000246 R13: ffff88801d2c3e80 R14: ffff888060f6e400 R15: 0000000000000004 lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0xea/0xc90 net/sched/sch_taprio.c:933 __run_hrtimer kernel/time/hrtimer.c:2074 [inline] __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2131 hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2148 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] run_ktimerd+0x6a/0x100 kernel/softirq.c:1174 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread timer wakeup didn't happen for 10596 jiffies! g56017 f0x0 RCU_GP_WAIT_FQS(5) ->state=I rcu: Possible timer handling issue on cpu=1 timer-softirq=32843 rcu: rcu_preempt kthread starved for 10597 jiffies! g56017 f0x0 RCU_GP_WAIT_FQS(5) ->state=I ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:27784 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:6021 Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 c4 bd 4d 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4b d1 03 00 cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc90000a3fab8 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8dae029b RDI: ffffffff8bcc4a80 RBP: 00000000ffffffff R08: 0000000000000100 R09: 0000000000000100 R10: dffffc0000000000 R11: fffffbfff1f64530 R12: 0000000000000246 R13: ffff88801d2c3e80 R14: ffff888060f6e400 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125cc4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3101f81e80 CR3: 000000000dfb0000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0xea/0xc90 net/sched/sch_taprio.c:933 __run_hrtimer kernel/time/hrtimer.c:2074 [inline] __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2131 hrtimer_run_softirq+0x1e1/0x2e0 kernel/time/hrtimer.c:2148 handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] run_ktimerd+0x6a/0x100 kernel/softirq.c:1174 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- This report is generated by a bot. 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