From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 100E1412C04; Fri, 4 Sep 2026 05:00:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788498053; cv=none; b=FYz3yXOuj6IBTa2hPdxByG5+qAf4CrIPRFZGM1YoPSyXOP2eDWokYRFkZEvM+db/w6rqkbruv2xaIEgbH35qLJzBqMXVrABziruQbIDmx1gO9Wimbli7X6A01A4g81MLRkHD/Qx2Uoj8AZOl8NJHT+sk4B801MoXMkrHa6xccas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788498053; c=relaxed/simple; bh=fuf94LVnuIEcErX5CphqLH8QqMz5ieftZj9IAIZNZ+w=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=LVl/RySDUJf2AA01MX6u7+6kDJaqUXuMis3OkbugK94fVn6/2YiLgqBxK9nkq1u7xS7TOcZpvJq/JTD8ft8irK2WGeKinUiLGuZUfSlw6mWRdmVYi/low5CjV4IJcbrjM7Ok/wFRj57bwCI4NZG9pIxQdiLimEPZq8Kq2r/dKZ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Oo+sjLpL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Oo+sjLpL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26DD81F00A3D; Fri, 4 Sep 2026 05:00:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788498051; bh=d1BzP2ibFwO6IwLrhlA20AGZDFwLvNEbw/qhJ+5IjN4=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=Oo+sjLpLTsV8hVOhmWCSnKVuXg9u6cjotWkfRMZ+IXR0ONQC7k+AlBVmF5hurxyfT Jl9xXbSuykHOyzdMaln0fJyqfyY0UHZtVZwavKQbYPSfSZa4RMs7FlVexvvR1LSnxK 8sPLTbh+K6YDVmqybr9KzYdaUiZFV7z9qTUPneM4L13nuQKUctFqByWr6UBG40vbD9 mHX9ONcRyiQ/hopE7bHydVspgGDJ+8rIjO5Sasb8mJs5StYcOJ6flO8w4Sg5RtIbwt hNCUkeMYwz0ZOzVClHItCHGKi6A3ANd+uqqg6ag2lf6vklbP87xrbDjcWK/RUjLlyS c7D8RjSOyRrGA== From: Thomas Gleixner To: syzbot , anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Cc: Catalin Marinas , Mark Rutland , Will Deacon Subject: Re: [syzbot] [kernel?] INFO: rcu detected stall in __hrtimer_run_queues (3) In-Reply-To: <6a95a3f2.99925153.16bd3d.0004.GAE@google.com> References: <6a95a3f2.99925153.16bd3d.0004.GAE@google.com> Date: Fri, 04 Sep 2026 07:00:48 +0200 Message-ID: <87o6eda9vj.ffs@fw13> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Mon, Aug 31 2026 at 08:55, syzbot wrote: CC+: ARM64 folks. It's their magic git tree .... Maybe some day syzbot people get their act together and actually figure out who should be CC'ed. Hope dies last... > syzbot has found a reproducer for the following issue on: > > HEAD commit: f1b8fa82cab7 Merge branch 'for-next/core' into for-kernelci > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > console output: https://syzkaller.appspot.com/x/log.txt?x=15aee379580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=d1128bc53f2ef7f3 > dashboard link: https://syzkaller.appspot.com/bug?extid=6d991f16f4bcc8eeea24 > compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 > userspace arch: arm64 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15632d9e580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15dd1c15580000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/932d85a2bda2/disk-f1b8fa82.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/5b6b8fb76e8d/vmlinux-f1b8fa82.xz > kernel image: https://storage.googleapis.com/syzbot-assets/c246b61ee396/Image-f1b8fa82.gz.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+6d991f16f4bcc8eeea24@syzkaller.appspotmail.com > > watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor:4831] > Modules linked in: > irq event stamp: 38640849 > hardirqs last enabled at (38640848): [] seqcount_lockdep_reader_access+0x7c/0xf8 include/linux/seqlock.h:75 > hardirqs last disabled at (38640849): [] __el1_irq arch/arm64/kernel/entry-common.c:527 [inline] > hardirqs last disabled at (38640849): [] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:543 > softirqs last enabled at (147672): [] local_bh_enable include/linux/bottom_half.h:33 [inline] > softirqs last enabled at (147672): [] put_cpu_fpsimd_context arch/arm64/kernel/fpsimd.c:251 [inline] > softirqs last enabled at (147672): [] do_sve_acc+0x32c/0x4b8 arch/arm64/kernel/fpsimd.c:1349 > softirqs last disabled at (148217): [] __do_softirq+0x14/0x20 kernel/softirq.c:656 > CPU: 0 UID: 0 PID: 4831 Comm: syz-executor Not tainted syzkaller #0 PREEMPT > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026 > pstate: 43400005 (nZcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) > pc : trace_hrtimer_expire_exit include/trace/events/timer.h:321 [inline] > pc : __run_hrtimer kernel/time/hrtimer.c:2035 [inline] > pc : __hrtimer_run_queues+0x32c/0xbe0 kernel/time/hrtimer.c:2096 > lr : arch_static_branch arch/arm64/include/asm/jump_label.h:36 [inline] > lr : trace_hrtimer_expire_exit include/trace/events/timer.h:321 [inline] > lr : __run_hrtimer kernel/time/hrtimer.c:2035 [inline] > lr : __hrtimer_run_queues+0x32c/0xbe0 kernel/time/hrtimer.c:2096 > sp : ffff80008eb67de0 > x29: ffff80008eb67e40 x28: 1fffe00034bb7c3a x27: ffff0001a5dbe1c0 > x26: ffff0000c6453a90 x25: ffff0000d1a50d38 x24: dfff800000000000 > x23: 0000000000000001 x22: ffff800084ec6bd4 x21: 1fffe00018c8a752 > x20: ffff0000c64545a8 x19: ffff0000c6453a80 x18: 0000000000000000 > x17: ffff80011d2d8000 x16: ffff80008eb60000 x15: 0000000000000000 > x14: 00000000ffff8000 x13: 0000000000000001 x12: 0000000000000000 > x11: 0000000000000000 x10: 0000000000000102 x9 : 0000000000000101 > x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 > x5 : 0000000000000001 x4 : 0000000000000008 x3 : ffff80008046a634 > x2 : 0000000000000001 x1 : ffff0000c6453a80 x0 : 0000000000000000 > Call trace: > arch_static_branch arch/arm64/include/asm/jump_label.h:36 [inline] (P) > trace_hrtimer_expire_exit include/trace/events/timer.h:321 [inline] (P) > __run_hrtimer kernel/time/hrtimer.c:2035 [inline] (P) > __hrtimer_run_queues+0x32c/0xbe0 kernel/time/hrtimer.c:2096 (P) > hrtimer_run_softirq+0x15c/0x21c kernel/time/hrtimer.c:2113 > handle_softirqs+0x2ec/0xd98 kernel/softirq.c:622 > __do_softirq+0x14/0x20 kernel/softirq.c:656 > ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:78 > call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:885 > do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:83 > invoke_softirq kernel/softirq.c:503 [inline] > __irq_exit_rcu+0x1ac/0x428 kernel/softirq.c:735 > irq_exit_rcu+0x14/0x84 kernel/softirq.c:752 > __el1_irq arch/arm64/kernel/entry-common.c:531 [inline] > el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:543 > el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:548 > el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:586 > __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P) > arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] (P) > _raw_spin_unlock_irqrestore+0x44/0x98 kernel/locking/spinlock.c:198 (P) > __debug_check_no_obj_freed lib/debugobjects.c:1180 [inline] > debug_check_no_obj_freed+0x2c8/0x3a4 lib/debugobjects.c:1201 > slab_free_hook mm/slub.c:2608 [inline] > slab_free mm/slub.c:6377 [inline] > kmem_cache_free+0x120/0x6b8 mm/slub.c:6504 > file_free+0x128/0x1dc fs/file_table.c:104 > __fput+0x538/0x74c fs/file_table.c:525 > fput_close_sync+0x10c/0x278 fs/file_table.c:617 > __do_sys_close fs/open.c:1511 [inline] > __se_sys_close fs/open.c:1496 [inline] > __arm64_sys_close+0x80/0x110 fs/open.c:1496 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 > do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 > el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758 > el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590 > Sending NMI from CPU 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 UID: 0 PID: 4802 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026 > Workqueue: rcu_gp process_srcu > pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) > pc : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] > pc : _raw_spin_unlock_irqrestore+0x44/0x98 kernel/locking/spinlock.c:198 > lr : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] > lr : _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:198 > sp : ffff80008eb77dc0 > x29: ffff80008eb77dc0 x28: 1fffe00034bbc63a x27: ffff0001a5de31c0 > x26: ffff0001a5de31d0 x25: ffff0000d2a4a538 x24: dfff800000000000 > x23: 0000000000000001 x22: ffff800084ec6bd4 x21: ffff0001a5de2d80 > x20: ffff0001a5de2d80 x19: 0000000000000000 x18: 00000000ffffffff > x17: ffff80008a7d6000 x16: 0000000000000002 x15: ffff80008a35fda0 > x14: ffff80008a5d5e28 x13: 0000000000000001 x12: 0000000000000000 > x11: ffff80008a5d5e28 x10: 0000000000000003 x9 : 0000000000000000 > x8 : 00000000000000c0 x7 : 0000000000000000 x6 : 0000000000000000 > x5 : 0000000000000001 x4 : 0000000000000008 x3 : ffff80008015611c > x2 : 0000000000000002 x1 : ffff0000d32c9d40 x0 : ffff80011d2fd000 > Call trace: > __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P) > arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] (P) > _raw_spin_unlock_irqrestore+0x44/0x98 kernel/locking/spinlock.c:198 (P) > __run_hrtimer kernel/time/hrtimer.c:2028 [inline] > __hrtimer_run_queues+0x22c/0xbe0 kernel/time/hrtimer.c:2096 > hrtimer_run_softirq+0x15c/0x21c kernel/time/hrtimer.c:2113 > handle_softirqs+0x2ec/0xd98 kernel/softirq.c:622 > __do_softirq+0x14/0x20 kernel/softirq.c:656 > ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:78 > call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:885 > do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:83 > invoke_softirq kernel/softirq.c:503 [inline] > __irq_exit_rcu+0x1ac/0x428 kernel/softirq.c:735 > irq_exit_rcu+0x14/0x84 kernel/softirq.c:752 > __el1_irq arch/arm64/kernel/entry-common.c:531 [inline] > el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:543 > el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:548 > el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:586 > __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P) > arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) > queue_delayed_work_on+0xf4/0x140 kernel/workqueue.c:2624 (P) > queue_delayed_work include/linux/workqueue.h:714 [inline] > srcu_reschedule+0x240/0x338 kernel/rcu/srcutree.c:1957 > process_srcu+0xd04/0x1eb8 kernel/rcu/srcutree.c:1991 > process_one_work kernel/workqueue.c:3322 [inline] > process_scheduled_works+0x788/0x10b8 kernel/workqueue.c:3405 > worker_thread+0x798/0xbd0 kernel/workqueue.c:3486 > kthread+0x304/0x3d4 kernel/kthread.c:436 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:838 > watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:3:4802] > Modules linked in: > irq event stamp: 44430735 > hardirqs last enabled at (44430734): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] > hardirqs last enabled at (44430734): [] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:198 > hardirqs last disabled at (44430735): [] __el1_irq arch/arm64/kernel/entry-common.c:527 [inline] > hardirqs last disabled at (44430735): [] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:543 > softirqs last enabled at (6136): [] softirq_handle_end kernel/softirq.c:468 [inline] > softirqs last enabled at (6136): [] handle_softirqs+0xc28/0xd98 kernel/softirq.c:650 > softirqs last disabled at (7461): [] __do_softirq+0x14/0x20 kernel/softirq.c:656 > > > --- > 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.