From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 DFEFD2356BE for ; Sun, 15 Feb 2026 08:48:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771145310; cv=none; b=EDU2MzHz9/3UsRbmTzzkaoActdoNToxFQfmTnSEwClnPZgeMXfpiGQRNmx1zootorGVflN4iHzUL51rt2HQzuUfWUHlqpQstc1RoKIw81w7zy+zsXUwMWYfS5rFgIU0dvefUbM39hT8rERX/L63I2m999xJzXchrzm7+XRnyVgc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771145310; c=relaxed/simple; bh=ULVGH4fbKOubNArUEzFzvZ6GU9gcg3/islpoEzjTfdM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=bVyZNIhrM3BoGcaqQ15nGwwwpUN7zL7GkYvjmWfGtKE230C34PSANcoV6lHv8hTSwPjbNWg1Q5bKK9yaq9uSR/emM0VvkKqPfH8w0s3u0OwcTdCdh2XLaQ9VF4uST0LqSUkqV5v7jI62tFX9aVz/wjQ6fXQJepuTArO1+KUZeio= 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=209.85.161.71 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-f71.google.com with SMTP id 006d021491bc7-67986abad39so7108862eaf.1 for ; Sun, 15 Feb 2026 00:48:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771145308; x=1771750108; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=2lwkIzr/ypT2MXA1Z4maxF9RnA7rXOrDaTApHVNSys8=; b=mVTfz/lX5B9OxHLLDRN4FmAV6TY7BpiEwWFA25JbfHib0/lPV7pbRZnbn8X+1cX5JJ 5AAGwCoQ2z7ZzLxObMyugc4282izwrT3rhWolixXnHC3g/bQnUhxw6tSarRzKFl2G43T W4Mo+07cMfEiRN8/AHIejjx6GIWNc9ev+I5OiIXLCv40EqKFy5B3sKg1knNebDSI5JJz VxOi0g927Ut6TW7DJ/GMUucCDz6lwLj+vhokB5LRZcsasVqfuqWxwIpeWbYZnqdl7Sy9 mGRPl6u7iMlonbjRAkR94vSLKEpWPTSAzRq+EUsvT8ucPISYlbD5V6p+/bI6yDBSpO9d xn3w== X-Gm-Message-State: AOJu0YwyhXtOECl9Y1GOf3qezJAdb0yG/mG/1dm4MPLfIQlFrZIxPU36 OaRc3ktt407QQDHS3km/KdYSCal+5Xtp3i55BH11/uifKCXfqobRNUrkG4SJk1yTiSZGS4TrCRC Y0LzJ2MSTZuiPm44ttv4dj/xjjht3dvf5Ce7uQSbpYJbXIXmyGx220lw+aC4= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1789:b0:679:5ff5:b5bb with SMTP id 006d021491bc7-6795ff5b6b3mr1288147eaf.74.1771145307789; Sun, 15 Feb 2026 00:48:27 -0800 (PST) Date: Sun, 15 Feb 2026 00:48:27 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6991885b.050a0220.340abe.02ef.GAE@google.com> Subject: [syzbot] [kernel?] KMSAN: uninit-value in __flush_smp_call_function_queue From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: ca4ee40bf13d Partly revert "drm/hyperv: Remove reference t.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=114ac722580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4b4f2aab682301f1 dashboard link: https://syzkaller.appspot.com/bug?extid=4b1bd55fba6260160779 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/68f5e4558a91/disk-ca4ee40b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ea1eab60444d/vmlinux-ca4ee40b.xz kernel image: https://storage.googleapis.com/syzbot-assets/cc7e3debdec4/bzImage-ca4ee40b.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4b1bd55fba6260160779@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: uninit-value in __flush_smp_call_function_queue+0x362/0x18e0 kernel/smp.c:535 __flush_smp_call_function_queue+0x362/0x18e0 kernel/smp.c:535 generic_smp_call_function_single_interrupt+0x1c/0x30 kernel/smp.c:463 __sysvec_call_function_single+0x4b/0x3e0 arch/x86/kernel/smp.c:271 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0x7c/0x90 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1f/0x30 arch/x86/include/asm/idtentry.h:704 kmsan_get_metadata+0x12e/0x160 mm/kmsan/shadow.c:148 kmsan_get_shadow_origin_ptr+0x35/0xb0 mm/kmsan/shadow.c:97 get_shadow_origin_ptr mm/kmsan/instrumentation.c:38 [inline] __msan_metadata_ptr_for_load_8+0x24/0x40 mm/kmsan/instrumentation.c:94 on_stack+0x5f/0x1f0 arch/x86/include/asm/stacktrace.h:56 update_stack_state+0xa7/0x1c0 arch/x86/kernel/unwind_frame.c:228 unwind_next_frame+0x116/0x350 arch/x86/kernel/unwind_frame.c:315 arch_stack_walk+0x1b0/0x280 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xc2/0x100 kernel/stacktrace.c:122 ref_tracker_alloc+0x1b2/0x7a0 lib/ref_tracker.c:277 __netdev_tracker_alloc include/linux/netdevice.h:4403 [inline] netdev_tracker_alloc include/linux/netdevice.h:4415 [inline] netdev_get_by_index+0xf6/0x1b0 net/core/dev.c:1020 fib6_nh_init+0x172/0x32c0 net/ipv6/route.c:3600 ip6_route_info_create_nh+0x4e4/0xf60 net/ipv6/route.c:3900 ip6_route_add+0x159/0x4a0 net/ipv6/route.c:3952 addrconf_add_mroute net/ipv6/addrconf.c:2552 [inline] addrconf_add_dev+0x6af/0x790 net/ipv6/addrconf.c:2570 inet6_addr_add+0x2d5/0x1570 net/ipv6/addrconf.c:3032 inet6_rtm_newaddr+0x1a0f/0x1dd0 net/ipv6/addrconf.c:5064 rtnetlink_rcv_msg+0x106f/0x14b0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x54d/0x680 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6985 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x10b2/0x1250 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0xa77/0xb90 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0x130/0x200 net/socket.c:2209 x64_sys_call+0x39a0/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable prefix created at: record_print_text+0xca/0x8e0 kernel/printk/printk.c:1420 printk_get_next_message+0xc7c/0x1250 kernel/printk/printk.c:3072 CPU: 0 UID: 0 PID: 15335 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 ===================================================== --- 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