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 E5AA83859C2; Tue, 21 Apr 2026 08:19:40 +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=1776759582; cv=none; b=bzkMgLHi46EGLtn1hlKJ4x8fiGPXcVb72p2wIT49MkdqjiIgc3lDxB2vjo6r4a0QlKapjIst/iBw+wd6rG6kTIGAQ1zbyhdNkTYU+0IVgx5AwjPw6MuSgGgTwt2YzU0Oi2HNQBKmeASSRbhLYiIPZIn7u3b7H+f5PIVP9eWGfPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776759582; c=relaxed/simple; bh=skS9sAxmUTtF+i1eMU/5DMsTUEtylqwxN2O3O2Wgaq8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MO+D78mXgK0EbGH9QubvRJQfuOAnjjv/XM6hz0VxUrJjkiL5INCaEqn+0MFQrnfRp7n6yrnZ3qi0nRwOMS72AXFEzy20URJ/sx1C0MjbyEOahc4J1YTR6Xb0rmPWG8ycfIDm25anHfhEL54YtvjOswQI1mpynPUr99She6JLx2o= 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=ob3bagR5; 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="ob3bagR5" 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=fGvmdupeMERdnRRGrdrk+FV4QqPGhplY/NanJt+t8j0=; b=ob3bagR5W2i8n767TmTtF29h3V YdnhVLJ+aCThjW0MbVCZKpgSNPBXvTW+8++c3drMzpOE8Gc7w8WD5U4ia+aoM2osyni4b3ppZhPJh v/tgbQekA38sxQG1mlP/lAkEP05NybQK6fCccxfObUyvUKStgyowLlTs60ZdeRaxLNhdo4ppCxh7m Vh3acOIUcYbMvcl2451Agwm1ju1cfv2/dA/JvTirRBT8i5Dek+apw4JeQGgkJhN77bC2WQ9NCUmHo iJh8Ry6sSepu17kGSrQR/NclrioByap3JrW8iEEAwlsrrD8n32RVWUzogc8bE0iZnbN6rFC06DTLs HhuCDRnA==; 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 1wF6KQ-000ifx-0U; Tue, 21 Apr 2026 08:19:31 +0000 Date: Tue, 21 Apr 2026 01:19:25 -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> 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: <20260421073738.22110-1-zlatistiv@gmail.com> X-Debian-User: leitao On Tue, Apr 21, 2026 at 10:37:38AM +0300, Nikola Z. Ivanov wrote: > Syzbot reports a KMSAN uninit-value originating from > nsim_dev_trap_skb_build, with the allocation also > being performed in the same function. > > The cause of the KMSAN warning is a missing assignment of > the tos and id fields of the ip header. > > Fix this by calling skb_put_zero instead of skb_put to > guarantee null initialization. > Additionally remove the now redundant zero assignments > and reorder the remaining ones so that they more closely > match the order of the fields as they appear in the ip header. > > 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"? Thanks for the fix, --breno