From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f79.google.com (mail-oo1-f79.google.com [209.85.161.79]) (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 F0AD378F2B for ; Thu, 28 May 2026 01:12:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779930752; cv=none; b=HujKrDQ8FsjVmkpu8fwPoIBojPyY7R5BgFOXrWKXF4xT4mKZglK/wwcbKwiJV8XMs5GZTgjur5i8C6mP+smgqA8ZJn+gPuCVAxdUGG6e5KGzqtW7HDDtljFn1nkctngCLEXV6+9RHy25ER0Ju4ZIMNRwt3X61WcpxdQqUZ6aWu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779930752; c=relaxed/simple; bh=eNCb8eSHaGQEwOI0h1a5TwyH7i4RwD75ly/B1Spcv5Q=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=hWVFvMyJXkroALP/DegbsJuAcao+3WAD3vsFGGgQuqYDL2lVFd5ZzMd7qtojiodIrUwWA2vpmmEklkpJ3kEKHLm57OOqz1Z1FEIugkXEZLPP3dO9nuJZrBPPeMmvTNfbgClQxQczHqMCHFHy9QhlCv382v7onJT7AIyt6BDw0co= 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=209.85.161.79 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-oo1-f79.google.com with SMTP id 006d021491bc7-69d8e34058cso4149354eaf.1 for ; Wed, 27 May 2026 18:12:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779930750; x=1780535550; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=9TEmRizXMIbGZYx1Ws9m3mt6dQBmNYp3px/KVX87cR4=; b=AGV2St2vCPc/M0w2rGsygRn/MCQKr8PQ5GJbms4asbeGcb0NAdGZaEVccn5CpMvwr3 W+E7lPPfyZtoup1VPYCKGxn5marJuuur1Soit9GEzQK4ulaG1Msyxzt1ZTub4tj3ZVbG v22Z+XCpsk6Q8yhZqFCWiZQOhweIa5+3BNLH3z2mcuM7onUIGchVwiGDIfK74rp6EsaS 0b//ZBMcgykT9CR2H18w3DjM3jO9N3cyQMXe30xEF3OTsvviOEfgXPcjzTgREHUvQILE dbpqO+b60JxcluPJabTEHpO+2z1sSMjth045v/d981HoYgoldpJlK2lOPSjM+XVR56Su FKyQ== X-Forwarded-Encrypted: i=1; AFNElJ8I7bpN0L5pYtx8Ae8YH4TY2B8c+7A32+9y+87GpfNrNKfdwd6LQ9A0IpB3VZrWgHf6oJi3JkMa@vger.kernel.org X-Gm-Message-State: AOJu0YwVmoSs3veYOpzG+Tddsy0V53uvxTU7NPCyYQJlHBek6wO8SpNa PgSaXWI0VsB+7IdDYt/uIdTYL4T5+/x1uB7LTCSsLhrf+32cBWhKCmWb7p4JWhglMYXXX+WUPiU glarEizOSYoSwhHbuJG/xaY/V4KAblQZoHw1ENw9/m2czNvIUKjf/qUxgIDg= Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:221d:b0:69d:e3b4:4e1b with SMTP id 006d021491bc7-69de3b44f12mr2974690eaf.55.1779930749986; Wed, 27 May 2026 18:12:29 -0700 (PDT) Date: Wed, 27 May 2026 18:12:29 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a17967d.5bfaf17f.38d970.0000.GAE@google.com> Subject: [syzbot] [cgroups?] [mm?] INFO: rcu detected stall in clone3 (6) From: syzbot To: akpm@linux-foundation.org, cgroups@vger.kernel.org, hannes@cmpxchg.org, jackmanb@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, surenb@google.com, syzkaller-bugs@googlegroups.com, vbabka@kernel.org, ziy@nvidia.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: e8c2f9fdadee Merge tag 'for-7.1/hpfs-fixes' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=131dcf96580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8d24a1331e060dda dashboard link: https://syzkaller.appspot.com/bug?extid=774c2dfaebdf78f984c5 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7980daa950e4/disk-e8c2f9fd.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8bdb257b9cb5/vmlinux-e8c2f9fd.xz kernel image: https://storage.googleapis.com/syzbot-assets/827a38d4946b/bzImage-e8c2f9fd.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+774c2dfaebdf78f984c5@syzkaller.appspotmail.com rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17948/1:b..l rcu: (detected by 0, t=10503 jiffies, g=351569, q=826004 ncpus=2) task:syz.4.14533 state:R running task stack:25592 pid:17948 tgid:17948 ppid:10462 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__rcu_read_unlock+0x0/0xe0 kernel/rcu/tree_plugin.h:431 Code: d9 80 e1 07 80 c1 03 38 c1 7c dc 48 89 df e8 07 77 85 00 eb d2 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff RSP: 0018:ffffc9000596f390 EFLAGS: 00000286 RAX: c3ba2f73bc45e400 RBX: 00007f67769da601 RCX: 0000000000000046 RDX: 0000000000000001 RSI: ffffffff8e220c4d RDI: ffffffff8c28b860 RBP: dffffc0000000000 R08: 0000000000000022 R09: ffffffff8e95cce0 R10: dffffc0000000000 R11: ffffffff81b0e040 R12: 00007fff7b795798 R13: ffffc90005968000 R14: ffffc9000596f468 R15: ffffffff8176e256 rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bbf/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5613 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4951 alloc_task_struct_node kernel/fork.c:187 [inline] dup_task_struct+0x52/0x840 kernel/fork.c:918 copy_process+0x89b/0x4440 kernel/fork.c:2090 kernel_clone+0x284/0x8f0 kernel/fork.c:2721 __do_sys_clone3 kernel/fork.c:3025 [inline] __se_sys_clone3+0x33c/0x360 kernel/fork.c:3004 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6775b9dc49 RSP: 002b:00007fff7b795798 EFLAGS: 00000202 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007f6775b591e0 RCX: 00007f6775b9dc49 RDX: 00007f6775b591e0 RSI: 0000000000000058 RDI: 00007fff7b7957f0 RBP: 00007f67769da6c0 R08: 00007f67769da6c0 R09: 00007fff7b7958d7 R10: 0000000000000008 R11: 0000000000000202 R12: ffffffffffffffe8 R13: 000000000000006e R14: 00007fff7b7957f0 R15: 00007fff7b7958d8 rcu: rcu_preempt kthread starved for 332 jiffies! g351569 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x389/0x470 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9543 Comm: kworker/u8:15 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xdd5/0x2550 arch/x86/kernel/unwind_orc.c:614 Code: 61 0b ba 00 48 89 5c 24 60 4c 89 64 24 18 49 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 <84> c0 0f 85 2c 12 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 RSP: 0018:ffffc90000a075f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90000a07c28 RCX: 1ffff92000140ed9 RDX: ffffffff914bec6a RSI: 0000000000000002 RDI: ffffffff8c28b800 RBP: 1ffff92000140eda R08: 000000000000000b R09: ffffffff8e95cce0 R10: dffffc0000000000 R11: ffffffff81b0e040 R12: ffffc90000a09000 R13: 1ffff92000140edb R14: ffffc90000a076c8 R15: ffffc90000a01000 FS: 0000000000000000(0000) GS:ffff888125387000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0dcae0021c CR3: 0000000090206000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6251 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6378 kfree_skb_reason include/linux/skbuff.h:1322 [inline] enqueue_to_backlog+0x69b/0xee0 net/core/dev.c:5421 netif_rx_internal+0x120/0x560 net/core/dev.c:5719 __netif_rx+0x78/0xc0 net/core/dev.c:5739 loopback_xmit+0x43a/0x660 drivers/net/loopback.c:90 __netdev_start_xmit include/linux/netdevice.h:5368 [inline] netdev_start_xmit include/linux/netdevice.h:5377 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:372 qdisc_restart net/sched/sch_generic.c:437 [inline] __qdisc_run+0xa83/0x1560 net/sched/sch_generic.c:445 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:4292 [inline] __dev_queue_xmit+0x1d26/0x3950 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] neigh_hh_output include/net/neighbour.h:544 [inline] neigh_output include/net/neighbour.h:558 [inline] ip_finish_output2+0xc68/0x1070 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 synproxy_send_client_synack+0x8c1/0xe30 net/netfilter/nf_synproxy_core.c:485 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6202 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 blake2s_compress+0xf9/0x1eb0 lib/crypto/x86/blake2s.h:42 blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:119 hmac+0x2d3/0x3b0 drivers/net/wireguard/noise.c:332 kdf drivers/net/wireguard/noise.c:367 [inline] message_ephemeral+0x255/0x310 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x257/0x830 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18d/0x350 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. 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 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