From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5C855883F; Mon, 8 Dec 2025 17:46:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765216015; cv=none; b=XHZyBUnbzXItRV+HT9dISAmkMEeHmRA/Wai/XbmtaUJ3i3tunp451jMddwHtP2axG2iFdjzbppbFZs1uMz+lMvyjyKaIfAkmbjFg/umJZnQILIJ0cg0eiOgiNMVGEGtobWW933AsBmgvpHg4PRFG5UQJ0kRySjIfNGYmbOyA5z8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765216015; c=relaxed/simple; bh=lrtC04Hq6yc4q9JeQsBKspd5vfd81itQLGxXAafXFX8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Q4l1ibCp/ETgBDVpw4EUuoUYElgiH6hZqZL1oLb1CwVXwInK30lZBz4ojCBa4G/TIiGhvhDYA8MB1kH0nDv+uJ4FPY63CH9WU3jDXv671WwONCR/CbdXWW0ywh8qMtUq0i1JnXDgyco9prIYOslYf0MKg9IK52oBiJuBZXeHy7c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dpFQcHXq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dpFQcHXq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9D48C4CEF1; Mon, 8 Dec 2025 17:46:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765216014; bh=lrtC04Hq6yc4q9JeQsBKspd5vfd81itQLGxXAafXFX8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dpFQcHXqCrlIE+zRIbAvx2AxM6M+lxFbKG5c4VkiRfRqw9ErJ6vI2fy1m4Z99ateP RZXhoBDcVC52K3ukNluxbYY4fGF1mx65IWCmz0piMsTybjHVNFjNLsbpQhCus4Qf1x XP26pvng1KtiYYisTTJobFSvAyBsYYj/tQ0WzteHPkjp13sJXp1s45T6sS6Aw8BQ4a XUPVM8mv87jqJxcqj3L3cRCbNbOWNpMOjtfGkSdocNuyfSXbuodSPW1GU1QbVsiS94 bHA6ht+2CwJaG/k4zlWi4jmgFgFZHgOTHUA0ozmQG3lxol9d/y42aN4dH1LJpDrjl+ NIEVtIO0GxvJw== Date: Mon, 8 Dec 2025 17:46:51 +0000 From: Simon Horman To: Dharanitharan R Cc: syzbot+5dd615f890ddada54057@syzkaller.appspotmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Edward Adam Davis Subject: Re: [PATCH] net: atm: lec: add pre_send validation to avoid uninitialized Message-ID: References: <202511281159.5dd615f890ddada54057@syzkaller.appspotmail.com> <20251207041453.8302-1-dharanitharan725@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: <20251207041453.8302-1-dharanitharan725@gmail.com> + Edward On Sun, Dec 07, 2025 at 04:14:53AM +0000, Dharanitharan R wrote: > syzbot reported a KMSAN uninitialized-value crash caused by reading > fields from struct atmlec_msg before validating that the skb contains > enough linear data. A malformed short skb can cause lec_arp_update() > and other handlers to access uninitialized memory. > > Add a pre_send() validator that ensures the message header and optional > TLVs are fully present. This prevents all lec message types from reading > beyond initialized skb data. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-by: syzbot+5dd615f890ddada54057@syzkaller.appspotmail.com > Tested-by: syzbot+5dd615f890ddada54057@syzkaller.appspotmail.com No blank lines between tags please. > > Closes: https://syzkaller.appspot.com/bug?extid=5dd615f890ddada54057 Likewise here. > > Signed-off-by: Dharanitharan R But more importantly, this seems to duplicate another patch that is under review: * [PATCH net v3] net: atm: implement pre_send to check input before sending https://lore.kernel.org/all/tencent_4312C2065549BCEEF0EECACCA467F446F406@qq.com/