From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE5E93A450A; Tue, 21 Apr 2026 09:12:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776762764; cv=none; b=jJS9CVlhVnGZA3usUltZ+BrKxf5de5EZj5FzKPXGDFiTExJdOYN49ccnSuHmNh3MI1IJk8LEVP/saxBBDlRaqORrCGCwYMRjKacUbLpeZPSykPwgbJNgcf5c78L8BWvGqo6AiLCRwWr3VnpAxTGijUioAHoRBQ/qybaMXgF/ZCs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776762764; c=relaxed/simple; bh=qMZCs19zNH6r1sbcN8n+CvL8pFRMZpKqdg5NUnhlPD4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HN2cdidIa9nwtYDgXWEECp7RlR7bZD2upxd+Ei060KdhZlRePWkptYbx6tS+Pylxf8o/gT5yU+HekGSvCdrvWAco1bdCVeucWufVrpeS7XWycMbaTZkXFW6Hg8n/59taXl1D5rcBC3gf13+RXmp9+Ot8cRjS0TKwKC9z3Qh4xd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=gksf2xDD; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="gksf2xDD" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=C5qtPTtRQKr+SHyFy1jM+p1ujYTR3Qaj3gDSKzuF8+M=; b=gksf2xDDSfp89q43dyM6nM3/yG rPLiP7/I0gzBMEcT+NiXry5h5rQVUY1ys2Y67PaYGKK01hAXhnWxdd/oFoUzDJO+PXljdkAUyZgFG Lve+iAmRmBYn2YWZeaNwGRaa5mlOsiNizNEnbjKI0g5TobuRleDlAwM+vjrh/KSExv12kzVejJvh3 Bkjrhwoq6ezVcQgYnSsFlyPc6IgWsTiILhEErCIxKjqAVgABtDypIvtM0GFD1a21Vl1bTWfo473/K z2FC+GGBgDFsbpdg9fug+r88HD0a+IWu8tWW5QiqlFdegRdHDm+f/paomqbQ7vJIjgvSM/Y7YCY6v V/u/zLjg==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wF79n-000kKF-1n; Tue, 21 Apr 2026 09:12:36 +0000 Date: Tue, 21 Apr 2026 02:12:31 -0700 From: Breno Leitao To: "Nikola Z. Ivanov" Cc: kuba@kernel.org, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] netdevsim: Initialize all fields of ip header when building dummy sk_buff Message-ID: References: <20260421073738.22110-1-zlatistiv@gmail.com> <9ce273bd-6912-4442-8672-4c89bebf32ed@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9ce273bd-6912-4442-8672-4c89bebf32ed@gmail.com> X-Debian-User: leitao On Tue, Apr 21, 2026 at 11:54:19AM +0300, Nikola Z. Ivanov wrote: > On 4/21/26 11:19 AM, Breno Leitao wrote: > > On Tue, Apr 21, 2026 at 10:37:38AM +0300, Nikola Z. Ivanov wrote: > > > > > > Closes: https://syzkaller.appspot.com/bug?extid=23d7fcd204e3837866ff > > > > How do you check in the report above that the missig un-initialized > > fields are "tos" and "id"? > > I don't think it is visible here, my guess would > be because the checksum calculator walks the > header in small chunks instead of referencing > its fields. > > The whole "KMSAN: uninit-value in irqentry_exit_to_kernel_mode_preempt" > doesn't really sound quite right. That's precisely my question - how does this fix relate to that specific report? Were you able to reproduce the KMSAN report? Thanks for the quick answer, --breno