From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f79.google.com (mail-ot1-f79.google.com [209.85.210.79]) (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 878883403E3 for ; Thu, 6 Aug 2026 04:47:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785991648; cv=none; b=f+deQDiBsjNzqGwg074yZOeDao9N1jXhEtf5q6H11aXzfUhxfGOaZ9oKQaw5dD9W9bPApCOU0k25CQsy1JH1CpDWPX3kYB0YbpIqZ6Qc97MUrN+3FA/U/vkG0ntFtM1hr8YOn6Hz67BOT/uCsPQxazY5jmx5lgM8lvPH7rhjqsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785991648; c=relaxed/simple; bh=fGVINHHgl4sPcGBemjH4XHr0VHl2Q9QmK3pENdeKnOQ=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=SmkmTpvKasCkuyEAdbEeWrGsKK7g3LB4scLwXCAbvKhA+cTq3I3RFuvakDcYQvAKAbSCVLOSqAXH6nsFOEoty0vsjYYy3jHjBy/ECbV37PadT/0HXJNmq8JNFcKH33LDWuu8tpZVbXzRW1eOFgdIcpOPPyOhRc4UqWU1fYIgF8I= 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=209.85.210.79 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-ot1-f79.google.com with SMTP id 46e09a7af769-7ee1e335245so1144522a34.1 for ; Wed, 05 Aug 2026 21:47:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785991645; x=1786596445; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=WlRcwDRvn7qQIjNUu3Q6RGqwDzBI81vHs+MEncx6g3E=; b=Y6YCQd3+Dl3hKPadkCq1OUcnc3Xfla/F9VoQx5Opeag3i+69Lc/lt+GsYihcHy6Com RGrZBov86vpiE90EnN2q2Ev0Ry5kf8yJcQDiX3Yl88xGTgw1p6fuemtnzR7INFkznVKr 3NjchLlWshlMwaTrNn2RzJURwEF4aRm241nDNlkb/7Tl3eIeY0ewByMR62zl8rvzPXe9 SnWd/gWWGGI5rcfnPyPpRnBIsgJcaDqk9ziP/UjWesrKvtA62APTIWo5WI+xyXKHlfW+ lN8Y4CcRnHwN6UAXsqbp04CamMKIqv9z6c03ZG5gmZJXNv/fwUoCgtZHwdW+NaVJ00q7 NaoA== X-Forwarded-Encrypted: i=1; AHgh+Rpq2xhf20DjDGdq5aQoKgSy9pfF0f4REIjZ78F+chDxo2GFGRYyjmJGcSnJtoYHu3vaEuoxMfAf0CQ38PQ=@vger.kernel.org X-Gm-Message-State: AOJu0YzkUSWd4DtNWAa57/Lpv6masUJUFNqg8hhzEh2OVrkuVKMzFjoy ZO+KX8048UcVxIZxpG+z2HpCWhxe5dw8+HUPgDtd3a64pSVooChsKkPbwr/POK4AXMbg1Qlect7 At7HMUVGBS3HEeAhSdcjZfThp0MUIFp5Q0e8Nlt2GyjDUcunvRl2DaoZk0Ak= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:83c1:20b0:6ae:a950:9fb8 with SMTP id 006d021491bc7-6aea950a187mr2121319eaf.23.1785991645487; Wed, 05 Aug 2026 21:47:25 -0700 (PDT) Date: Wed, 05 Aug 2026 21:47:25 -0700 In-Reply-To: <6a7159d5.9511d2ce.1fc5b9.0333.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a7411dd.9c11d2ce.289b96.0094.GAE@google.com> Subject: Re: [syzbot] [serial?] WARNING in register_console From: syzbot To: gregkh@linuxfoundation.org, jirislaby@kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 0d8395707651 Merge tag 'soc-fixes-7.2-2' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10883c99580000 kernel config: https://syzkaller.appspot.com/x/.config?x=cb17729fb04b1e3a dashboard link: https://syzkaller.appspot.com/bug?extid=1ebbc20f223b99446034 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b1bbb9580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/14b35ca281d5/disk-0d839570.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/68c2ac2fdce0/vmlinux-0d839570.xz kernel image: https://storage.googleapis.com/syzbot-assets/29bdd737b48f/bzImage-0d839570.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/cce97dbb2265/mount_0.gz fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=11da8e49580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1ebbc20f223b99446034@syzkaller.appspotmail.com printk: legacy console [ttyS0] enabled ------------[ cut here ]------------ IS_ERR(kt) WARNING: kernel/printk/printk.c:3728 at legacy_kthread_create kernel/printk/printk.c:3728 [inline], CPU#0: syz.4.49/6392 WARNING: kernel/printk/printk.c:3728 at printk_kthreads_check_locked+0x2a7/0x3f0 kernel/printk/printk.c:3802, CPU#0: syz.4.49/6392 Modules linked in: CPU: 0 UID: 0 PID: 6392 Comm: syz.4.49 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:legacy_kthread_create kernel/printk/printk.c:3728 [inline] RIP: 0010:printk_kthreads_check_locked+0x2a7/0x3f0 kernel/printk/printk.c:3802 Code: fe c1 38 c1 7c 9a 4c 89 f7 e8 c5 85 8a 00 eb 90 e8 7e 12 21 00 eb 05 e8 77 12 21 00 b0 01 88 05 2f a4 08 18 e9 e2 00 00 00 90 <0f> 0b 90 48 c7 c7 80 bd 6d 8b e8 1a 9f 82 ff 48 8b 1d 93 9e 04 18 RSP: 0018:ffffc9000509fa70 EFLAGS: 00010206 RAX: fffffffffffffffc RBX: 0000000000000001 RCX: 10959546c0351c00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000509fb70 R08: ffff888032eb2daf R09: 1ffff110065d65b5 R10: dffffc0000000000 R11: ffffed10065d65b6 R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff92000a13f5c R15: dffffc0000000000 FS: 00007f7f4a99d6c0(0000) GS:ffff888125c3e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd99747f000 CR3: 000000003dd70000 CR4: 00000000003526f0 Call Trace: register_console+0xc19/0xfc0 kernel/printk/printk.c:4221 console_store+0x359/0x4f0 drivers/tty/serial/serial_core.c:2999 kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7f4b35e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7f4a99d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7f4b5e6090 RCX: 00007f7f4b35e0d9 RDX: 0000000000000002 RSI: 0000200000000600 RDI: 0000000000000004 RBP: 00007f7f4b3f5024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7f4b5e6128 R14: 00007f7f4b5e6090 R15: 00007ffcc0cedea8 --- 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.