From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f78.google.com (mail-oo1-f78.google.com [209.85.161.78]) (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 A418F2FE052 for ; Sat, 6 Dec 2025 14:30:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765031435; cv=none; b=fBtlm06p8Tc49rQPNyvdPuSBT1uHD7OaiTkaHns6O2sncuDxujW3y5gBHH4MyF/HYZValAjI+elG+qV3T6QfAtuvZFpYYpqVqmUU8MTrw2xC5b3EjKNftc6FhQ9ZCpk31QWumyjGhN8fqKKfgIIrZkcotWPItgAPyJC3Kfg7VNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765031435; c=relaxed/simple; bh=3TFhak2YSahSxHE1YUSKNyfo7KjekW4gq4U4X+O9aAM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=chi6mb6VWypaHGdVQCYa9UodFGQYruFdytVCbXimpCEXFWanwpFnPip7gmLxASHdLnLWgrbf+doWPjo5nMQtp8ZDzNk3XqLXP5UhUaw5tjDFk2XneK+sVODdUfaIld00Ios+plKA+/TmFgTmREexRmE4pvLn//QQQb4/bZ08zlY= 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=209.85.161.78 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-f78.google.com with SMTP id 006d021491bc7-657a467228eso4327177eaf.0 for ; Sat, 06 Dec 2025 06:30:33 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765031433; x=1765636233; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=22XLJG4IoHX/vssE3jx4zVEhx1Ft3Or66I+HMCqbSKs=; b=Pdrjt6j07UDWbbJDcaGLQHLf9eDyyxO72slSqWupMHhvxklz988tkn+VWaOpkndx8J j/nIFnrCt/Ii5rVSGhK6ElKjnL4XDGwU83OxSACidhGZ8/JC4l1dIIFq+d1U/H4WAsQ2 7RF+xozM4gpgJ9KyOGO+PuOqipx6BZDsiifzEA+2GfxITVHIavpB+4whk6hxDzv/UlPe YU0yRVl22x3Rc68f76yhE5h6J4Z4Q+qWPV9eXnsmMt9GpfLWXOiyOJ6m0cKMKrLuUJSX ckJr1Qd45PlO9GqXkk1gEWsjVIQtJjXAejLUgaHT5QhvXjaKH3dN/yE8qytUtZoEWQBz fLwA== X-Forwarded-Encrypted: i=1; AJvYcCV6BuOMNEyAYdk5nRXIk7yLGB12mJTzFESqhtrUvKA2y9j7aWezCJOmjzr+VEHLBRk3AGVHHAdnZ3Iw/Dc=@vger.kernel.org X-Gm-Message-State: AOJu0Yz/1Vr9i11k357k1FWFKcwnnF8bwO5f8ABQMEI8t+nITnY4nVhy GIAredweC7zUxZhdKa3AcCRLp6coGJDSM+nrSdK3sCY/uFnvJ1VSCl1R7HsUTeo3IWn/n6PAuM8 f7FsBt4pb7NZu0ZhYugqo8bUJWxTuISMxayV+Lg8HhOGByWwtXcvr452eFns= X-Google-Smtp-Source: AGHT+IEEj7MYdKDsPLMjpUH5K24m9WFXs3U4v7IiFPMBic29e52jpBICNzlK0PRVYoNg/wIVEnk1YgNZCozrqPcGwUi8sQAOACEW Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:200f:b0:659:9a49:8fc6 with SMTP id 006d021491bc7-6599a973d3fmr966986eaf.63.1765031432847; Sat, 06 Dec 2025 06:30:32 -0800 (PST) Date: Sat, 06 Dec 2025 06:30:32 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69343e08.a70a0220.38f243.002c.GAE@google.com> Subject: [syzbot] [bpf?] KMSAN: uninit-value in handle_bug From: syzbot To: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, haoluo@google.com, john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org, linux-kernel@vger.kernel.org, martin.lau@linux.dev, sdf@fomichev.me, song@kernel.org, syzkaller-bugs@googlegroups.com, yonghong.song@linux.dev Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: cc25df3e2e22 Merge tag 'for-6.19/block-20251201' of git://.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16c2eab4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=6c445efc9db431cb dashboard link: https://syzkaller.appspot.com/bug?extid=ba80855313e6fa65717a 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/a1afac06cfc1/disk-cc25df3e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/7bd5369ac00a/vmlinux-cc25df3e.xz kernel image: https://storage.googleapis.com/syzbot-assets/e183dedd04c6/bzImage-cc25df3e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ba80855313e6fa65717a@syzkaller.appspotmail.com ------------[ cut here ]------------ ===================================================== BUG: KMSAN: uninit-value in vsnprintf+0x15d9/0x1b30 lib/vsprintf.c:2911 vsnprintf+0x15d9/0x1b30 lib/vsprintf.c:2911 vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2255 vprintk_emit+0x27b/0xc50 kernel/printk/printk.c:2402 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2441 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82 __warn_printf lib/bug.c:187 [inline] __report_bug+0xa53/0xe80 lib/bug.c:240 report_bug_entry+0x148/0x1d0 lib/bug.c:265 handle_bug+0xe1/0x230 arch/x86/kernel/traps.c:430 exc_invalid_op+0x1f/0x50 arch/x86/kernel/traps.c:489 asm_exc_invalid_op+0x1f/0x30 arch/x86/include/asm/idtentry.h:616 reg_bounds_sanity_check+0x577/0x1450 kernel/bpf/verifier.c:2742 reg_set_min_max+0x3be/0x450 kernel/bpf/verifier.c:16572 check_cond_jmp_op+0x3a87/0x5380 kernel/bpf/verifier.c:17016 do_check_insn kernel/bpf/verifier.c:20441 [inline] do_check+0x23ef/0x16a50 kernel/bpf/verifier.c:20581 do_check_common+0x2217/0x3370 kernel/bpf/verifier.c:23865 do_check_main kernel/bpf/verifier.c:23948 [inline] bpf_check+0x1e78c/0x27610 kernel/bpf/verifier.c:25255 bpf_prog_load+0x2af6/0x3100 kernel/bpf/syscall.c:3088 __sys_bpf+0x7df/0xeb0 kernel/bpf/syscall.c:6164 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline] __se_sys_bpf kernel/bpf/syscall.c:6272 [inline] __x64_sys_bpf+0xa4/0xf0 kernel/bpf/syscall.c:6272 x64_sys_call+0x31c3/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: vsnprintf+0x15d2/0x1b30 lib/vsprintf.c:-1 vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2255 vprintk_emit+0x27b/0xc50 kernel/printk/printk.c:2402 vprintk_default+0x3f/0x50 kernel/printk/printk.c:2441 vprintk+0x36/0x50 kernel/printk/printk_safe.c:82 __warn_printf lib/bug.c:187 [inline] __report_bug+0xa53/0xe80 lib/bug.c:240 report_bug_entry+0x148/0x1d0 lib/bug.c:265 handle_bug+0xe1/0x230 arch/x86/kernel/traps.c:430 exc_invalid_op+0x1f/0x50 arch/x86/kernel/traps.c:489 asm_exc_invalid_op+0x1f/0x30 arch/x86/include/asm/idtentry.h:616 Local variable run_ctx.i created at: __bpf_trace_run kernel/trace/bpf_trace.c:2063 [inline] bpf_trace_run4+0xdf/0x590 kernel/trace/bpf_trace.c:2118 __bpf_trace_sched_switch+0x221/0x290 include/trace/events/sched.h:220 CPU: 1 UID: 0 PID: 23594 Comm: syz.7.5009 Tainted: G W syzkaller #0 PREEMPT(none) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ===================================================== --- 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