From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f208.google.com (mail-oi1-f208.google.com [209.85.167.208]) (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 CA06826ED5C for ; Sun, 4 Jan 2026 22:55:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767567329; cv=none; b=SqXg3McowKN6fqL0Oad3oRZcMnTSO4kbjv+LQeF7R8nFdliXM9qqJhbJ+gjPD+YTeEVP4cKsRtttJNrO7m8X87sr2eXzwZf4mTcjWADkovnW8EGbpo2KrR0D/M+556UrDNQzevAAQ1qEIj71JJ6LF1wQv2Vkg1MCDyuZmGstvAk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767567329; c=relaxed/simple; bh=wK9dkgyQe+qcTgBIitwVL+eGJOkAk6Liv3kjyLp+5Tw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=BdzgjZlVwcS+LMIywhpgHudTzVQR6a5IP8wIkz4I+6sijSRDXdyLj2JJ+rkmjY6Aq+pw3wOk08jRM/8TJPv3o9RBFs+kIkTo/du1MMttqRRIFI4nVBHb79txWle4PeLcOynM6Ymrs2kiTha6Dt4nXkfQtKcgVBrbyVjQyXwSbZQ= 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=209.85.167.208 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-f208.google.com with SMTP id 5614622812f47-451064d84edso24524703b6e.3 for ; Sun, 04 Jan 2026 14:55:27 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767567326; x=1768172126; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=GHDYlZf94AS+G7cLIq5M+2mDSeJdKWi1Id/byGiEgBs=; b=O1ygYfgkNMuqPHa2BETjdhvhql2A8MboUSGDqSaJXZq9weoUn3+BZRgondWyTq2rtL gYQ6Qux1Q2TNe2jR8VSrK+t7kNSUdkeNi8ptKf+bE8BfXB2oKv5FgZZ3Y6VVn+XwpzM+ lxldjBDRtWo7u1uxpN/OZ+zdtKCDIwoI1RfqIBA0J1Z3gNJBBxsjCMGoUcVAcMEt9DoZ cVneYh+IozxQGhgt5vdwEw58RacSKETz3E9fpdP6iKf2XwDBLcb1PaMVGCOfB+z5fHCz 4sZSSHnAoWVOtN979C9+1lsNs5n/NdsLAVMCTuHlr7beZCMq9+lNuyNcfiqu9HoW5DCe HPuw== X-Forwarded-Encrypted: i=1; AJvYcCXxTo3B/XaJn0hOBXUUbAxGhaxUWwAIfWXDzYYZxfUvK27QCMEupJ3cYIYe+T11F9Wfg5S08ghGxJ+p6uU=@vger.kernel.org X-Gm-Message-State: AOJu0YyBQaLwMsFuheCw+27wDwoBRMts2S1kRRDSg0aSsfO0WCXCXQUX bLTzIBjaJHvdpznUwCE5+jKwiciwPWA8HbMQq2JdMhIDLErKENsQHT6aYnZCj6z5/5sTAoXTtUU eNRSwWFY0o6lGAeONRUINuqSyrM2f7ETRsGBxrKplmP47bp+zd7ntQxhRE4o= X-Google-Smtp-Source: AGHT+IFw2wm/8+aX+PheNQj8ESAdiDTbAV78xUBKGIeYofmwvOqmUMJEeECR7u/reO+mEiKy/AFqfozRJkF5VTprxM7OcpJKIVY5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:151b:b0:65d:4d:4243 with SMTP id 006d021491bc7-65d0eb2e757mr21046533eaf.45.1767567326558; Sun, 04 Jan 2026 14:55:26 -0800 (PST) Date: Sun, 04 Jan 2026 14:55:26 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <695aefde.050a0220.1c9965.001d.GAE@google.com> Subject: [syzbot] [kernel?] KMSAN: uninit-value in pwq_dec_nr_in_flight (2) From: syzbot To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: c8ebd433459b Merge tag 'nfsd-6.19-2' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1779b222580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b3903bdf68407a14 dashboard link: https://syzkaller.appspot.com/bug?extid=b7af73b6a9490f27605c compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7ee938141d22/disk-c8ebd433.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/19e1ae73de06/vmlinux-c8ebd433.xz kernel image: https://storage.googleapis.com/syzbot-assets/2172b115d36a/bzImage-c8ebd433.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b7af73b6a9490f27605c@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: uninit-value in wq_node_nr_active kernel/workqueue.c:1555 [inline] BUG: KMSAN: uninit-value in pwq_dec_nr_active kernel/workqueue.c:1930 [inline] BUG: KMSAN: uninit-value in pwq_dec_nr_in_flight+0x14f/0x1d70 kernel/workqueue.c:1991 wq_node_nr_active kernel/workqueue.c:1555 [inline] pwq_dec_nr_active kernel/workqueue.c:1930 [inline] pwq_dec_nr_in_flight+0x14f/0x1d70 kernel/workqueue.c:1991 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0x171b/0x1d80 kernel/workqueue.c:3340 worker_thread+0xedf/0x1590 kernel/workqueue.c:3421 kthread+0xd5c/0xf00 kernel/kthread.c:463 ret_from_fork+0x208/0x710 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Uninit was created at: slab_post_alloc_hook mm/slub.c:4960 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x9e7/0x17a0 mm/slub.c:5315 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586 __alloc_skb+0x805/0x1040 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc5/0xa60 net/core/skbuff.c:6712 __virtio_vsock_alloc_skb_with_frags include/linux/virtio_vsock.h:68 [inline] virtio_vsock_alloc_linear_skb include/linux/virtio_vsock.h:81 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:87 [inline] virtio_transport_alloc_skb+0xcb/0x1350 net/vmw_vsock/virtio_transport_common.c:267 virtio_transport_send_pkt_info+0xaf1/0x1cd0 net/vmw_vsock/virtio_transport_common.c:390 virtio_transport_stream_enqueue net/vmw_vsock/virtio_transport_common.c:1113 [inline] virtio_transport_seqpacket_enqueue+0x1f0/0x260 net/vmw_vsock/virtio_transport_common.c:841 vsock_connectible_sendmsg+0x1336/0x1b60 net/vmw_vsock/af_vsock.c:2158 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x333/0x3d0 net/socket.c:742 ____sys_sendmsg+0x863/0xcf0 net/socket.c:2592 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2646 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2735 __do_sys_sendmmsg net/socket.c:2762 [inline] __se_sys_sendmmsg net/socket.c:2759 [inline] __x64_sys_sendmmsg+0xc6/0x150 net/socket.c:2759 x64_sys_call+0x2458/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:308 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 0 UID: 0 PID: 3966 Comm: kworker/u8:22 Tainted: G W L syzkaller #0 PREEMPT(none) Tainted: [W]=WARN, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: 0x0 (loop2) ===================================================== --- 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