From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f79.google.com (mail-oa1-f79.google.com [209.85.160.79]) (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 899DB2FD7B1 for ; Fri, 30 Jan 2026 21:10:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769807423; cv=none; b=lDZU6bLnXeNhuuXVdfjjoIImWbvDe437TG4B69ZCGJZrHBVNv4qtRqwn0SZW0lRl/Wd2Ap/B0VOUvIj+VayhoiFfXVlgC5tCg/PssrskytG/G4Rw4SvyapAEHDHuuV6R6prmz+u8zAwIIuIrC1g8jdT0mvXwmlAfsXORuNXIE/o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769807423; c=relaxed/simple; bh=PdiRSXzYu1euyTU2WpNl5UXa/gmZu1rxcA55P7nAY6w=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=pbGvTBVvHG7+of9WUou5s4emBqGASyXtPo9CtLpUpyhFeyNMjElyEY00LKq4t7Gavyf/UCJYSrkCVojhupdNZnlMrqghLZMaeotimEMhE4R7sbDkkSwObdAXl3Q5u5t4VKFiJFYci2POQY+Fiu0cqStJ86mWrYkldkqxQMAgtPI= 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=209.85.160.79 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-oa1-f79.google.com with SMTP id 586e51a60fabf-3fda4037d48so6600264fac.2 for ; Fri, 30 Jan 2026 13:10:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769807420; x=1770412220; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=JTzRT1hu6lYZNRa385VtNpleeAjhmLpZmYZhOIPgVTk=; b=vbAscGFzgTOJF+SckZRuGopOa4t/vOsAoVYPHtpaqbO4zZXJdE5JKAZWxsErdrjHJI z38hCAL4Rs63/UVAauFc5c43HyRK+Ssl/Xv5ZlqD5ZmL8v8K7lufWpnwRIknj7zascoi 9AQYrZi5M9knIqCih9Hs9oxQYPHvifIiHk0/tY2VoZyNNiaBhgJEqwIxN4ZGCGDj9kc6 1iAXbQ176O1qzKfdBMzh25NSADreVT1pmFXhoudW93Bt0Yce3p4/c8lPCX+HqCMLux4+ m3IyvJVc3RqGy9N2h6a+060TtmBlc5SpI3DooS07z8vogHjeAhzmAqSWRrN/TWwnpCpV n4uw== X-Forwarded-Encrypted: i=1; AJvYcCWpxUuA+GkE985Xbc3QwhVMSCzrx9MMOKChvmYQxOeCeWIIKsBFYjpWrhsRcoDOykizlcpEurBNa7ULn+0=@vger.kernel.org X-Gm-Message-State: AOJu0YwcDS0OfwR7VmZoEYjWZ6B/FGv7Ri3IGuA2i6uYSViQ02m57dS3 s9iBReMEUWMiaFMv6syK6JRHhjKzOh1QrVnPkkbmZSeABRVE/QO+EOniuOWH+/4OLJDuGKUwKhH IUGq21Da6a4l1imDfv3BZttnzb2P36eHbyWI0aaRG/efcFsXgH/hiKYGxN6M= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:5046:b0:663:2b12:1500 with SMTP id 006d021491bc7-6632b1220f1mr676341eaf.76.1769807420326; Fri, 30 Jan 2026 13:10:20 -0800 (PST) Date: Fri, 30 Jan 2026 13:10:20 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <697d1e3c.050a0220.16b13.008f.GAE@google.com> Subject: [syzbot] [kernel?] KMSAN: uninit-value in pick_task_fair 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@kernel.org, x86@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 63804fed149a Linux 6.19-rc7 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17b10a44580000 kernel config: https://syzkaller.appspot.com/x/.config?x=9682a42d8ec8b05c dashboard link: https://syzkaller.appspot.com/bug?extid=edaa9ae65c490cb55bf2 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/68dae8bb75e6/disk-63804fed.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1990ce72fe38/vmlinux-63804fed.xz kernel image: https://storage.googleapis.com/syzbot-assets/c2c358d127c9/bzImage-63804fed.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+edaa9ae65c490cb55bf2@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: uninit-value in pick_task_fair+0x29d/0x510 kernel/sched/fair.c:8890 pick_task_fair+0x29d/0x510 kernel/sched/fair.c:8890 pick_next_task_fair+0x120/0x2550 kernel/sched/fair.c:8918 __pick_next_task+0x108/0x6e0 kernel/sched/core.c:5890 pick_next_task kernel/sched/core.c:5983 [inline] __schedule+0xee5/0x8180 kernel/sched/core.c:6809 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x17c/0x3c0 kernel/sched/core.c:6964 worker_thread+0x1b45/0x1de0 kernel/workqueue.c:3436 kthread+0xd5a/0xf00 kernel/kthread.c:463 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Uninit was created at: slab_free_hook mm/slub.c:2466 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x32b/0x1400 mm/slub.c:6882 kobject_uevent_env+0x879/0x12a0 lib/kobject_uevent.c:639 kobject_uevent+0x36/0x50 lib/kobject_uevent.c:656 driver_register+0x60d/0x6a0 drivers/base/driver.c:257 usb_register_driver+0x206/0x620 drivers/usb/core/driver.c:1078 __usb_serial_register_drivers+0x319/0x16a0 drivers/usb/serial/usb-serial.c:1505 usb_serial_module_init+0x33/0x40 drivers/usb/serial/aircable.c:156 do_one_initcall+0x22b/0xad0 init/main.c:1378 do_initcall_level+0x157/0x2e0 init/main.c:1440 do_initcalls+0x176/0x310 init/main.c:1456 do_basic_setup+0x1d/0x30 init/main.c:1475 kernel_init_freeable+0x213/0x430 init/main.c:1688 kernel_init+0x2f/0x5e0 init/main.c:1578 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 CPU: 1 UID: 0 PID: 3516 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Workqueue: 0x0 (events_unbound) ===================================================== --- 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