From nobody Sun Feb 8 01:33:38 2026 Received: from mail-il1-f208.google.com (mail-il1-f208.google.com [209.85.166.208]) (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 79E353491F8 for ; Tue, 21 Oct 2025 16:26:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.208 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761064021; cv=none; b=RmHfvxjLwFt8Y46V7wqCBGDtIMlKcmuLCMpnFTAtahpNsKpOGn779mW41FgFi8URuwmnyiWVP+rE9j3BDvumj1JAzgeOkLEEH9MkuSE0nUChD3mnFQhTw5O8oQDj9RERvPduWem1HJ3tlxv7Zr8HZA9RFv7N9QKZG39LdY5w8MM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761064021; c=relaxed/simple; bh=UJrHEvcSfi/Pka2cgWnZ3GgnBH7EVZquQA2PoG2f1vg=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=cNs1lk+89IpuCM9b9v25H1yPOuCEHoJ4FSFoECQPzKTb/zDZ9BKTF/8ckzqWg/DkHheP0H+jeuo7Jo46Bnkn0E6aFt9QrZ+2QaeUG1latDLDycYgxCoyAoe4jM9Hkf6sg3kKiG6z66mEqyGmTXL50x/5sQaJl46zPosNyziWv6Q= 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=209.85.166.208 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-il1-f208.google.com with SMTP id e9e14a558f8ab-430db6d36c6so95778345ab.2 for ; Tue, 21 Oct 2025 09:26:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761064018; x=1761668818; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pFdC+aSTmJfkazoCMziwNnodu4GwgClZcM8jfns2mRc=; b=manfSOzpPms638sUdtGywAG5N1TfNejzZNASUifYGlK9bwfHu/EYn7DJG/bYfz4Tbf ibDGn00ftVU5Jkbomz9yB9e/d9Wk09FhRnB1mXZflZgl0Z/1iPVlkkYHURJ6QgW9oGt4 RHzacWPVFhaNlULt5VMKtX2u0q59ITqSQSaO3QlsKLkhqAVe6VizGpk1EjbxEgthEsI2 i/CsFF2+3hKLoP9FbddLHL9RlUWsYS2sXr7hs0/hTNfSSj7jHMQ7CSB+0Pf7c5QOpYbS EJDC3oBbeg9cL5IYsNXuad4lLipHI5LPYjtr3YuXdwQbtiH4hij/Qv6nXVcB/c+HcXmU sDQw== X-Gm-Message-State: AOJu0Yw7pDL7knGR9f2zC6jb2lu1+w4EuKMHClknzqM29dWDWAF7ybSz 2hGR0NReQzbBeGwP8nbUeBn7xs98IY+BmdLj5cHnGiXA6AJdxPTFs5KiCRwJo3ZIieVnsmoXu+w BS+On8Qfz7gXldvFL9Up4f7FfhGwsLc6tmvJQNox7nDFS8Sx1GfdBbhCGAv29uw== X-Google-Smtp-Source: AGHT+IExqRJuHMdWm4oqScDfjCwF+h4BUlmYlDFFwMuP1PgIslh+gllR0FhSzvM3zHhc+/iQPZVsBCiXpRaGRg+Z8E8PMx1aoBsT Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1b02:b0:427:a3ef:5701 with SMTP id e9e14a558f8ab-430c5232b53mr279873095ab.14.1761064018604; Tue, 21 Oct 2025 09:26:58 -0700 (PDT) Date: Tue, 21 Oct 2025 09:26:58 -0700 In-Reply-To: <68f6a4c8.050a0220.1be48.0011.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68f7b452.a70a0220.3bf6c6.0008.GAE@google.com> Subject: Forwarded: Re: [syzbot] [bpf?] WARNING in bpf_bprintf_prepare (3) From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: Re: [syzbot] [bpf?] WARNING in bpf_bprintf_prepare (3) Author: chandna.sahil@gmail.com On Mon, Oct 20, 2025 at 02:08:24PM -0700, syzbot wrote: >Hello, > >syzbot found the following issue on: > >HEAD commit: a1e83d4c0361 selftests/bpf: Fix redefinition of 'off' as d= .. >git tree: bpf >console output: https://syzkaller.appspot.com/x/log.txt?x=3D12d21de2580000 >kernel config: https://syzkaller.appspot.com/x/.config?x=3D9ad7b090a18654= a7 >dashboard link: https://syzkaller.appspot.com/bug?extid=3Db0cff308140f79a9= c4cb >compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976= -1~exp1~20250708183702.136), Debian LLD 20.1.8 >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D160cf5425800= 00 >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=3D128d5c58580000 > >Downloadable assets: >disk image: https://storage.googleapis.com/syzbot-assets/2f6a7a0cd1b7/disk= -a1e83d4c.raw.xz >vmlinux: https://storage.googleapis.com/syzbot-assets/873984cfc71e/vmlinux= -a1e83d4c.xz >kernel image: https://storage.googleapis.com/syzbot-assets/16711d84070c/bz= Image-a1e83d4c.xz > >The issue was bisected to: > >commit 7c33e97a6ef5d84e98b892c3e00c6d1678d20395 >Author: Sahil Chandna >Date: Tue Oct 14 18:56:35 2025 +0000 > > bpf: Do not disable preemption in bpf_test_run(). > >bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=3D172fe492580= 000 >final oops: https://syzkaller.appspot.com/x/report.txt?x=3D14afe492580= 000 >console output: https://syzkaller.appspot.com/x/log.txt?x=3D10afe492580000 > >IMPORTANT: if you fix the issue, please add the following tag to the commi= t: >Reported-by: syzbot+b0cff308140f79a9c4cb@syzkaller.appspotmail.com >Fixes: 7c33e97a6ef5 ("bpf: Do not disable preemption in bpf_test_run().") #syz test diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 1b61bb25ba0e..6a128179a26f 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -1021,7 +1021,9 @@ u32 bpf_flow_dissect(struct bpf_prog *prog, struct bp= f_flow_dissector *ctx, (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); flow_keys->flags =3D flags; =20 + preempt_disable(); result =3D bpf_prog_run_pin_on_cpu(prog, ctx); + preempt_enable(); =20 flow_keys->nhoff =3D clamp_t(u16, flow_keys->nhoff, nhoff, hlen); flow_keys->thoff =3D clamp_t(u16, flow_keys->thoff, --