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 B042F28C864; Thu, 11 Dec 2025 10:30:47 +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=1765449049; cv=none; b=MerZbn7wcYimt1P83PCnA+rwGifZxT5WwTll/v5fnPfN8NFWMUzzKW4oVjzTCwk0zM/U+gZ5m8uXVaofJoaWmvRJMXFbwJxalxdWY9OCt5g4tmsdZBYBz7Rg7gz6JwqfobdTtz7B+gkgyUNMVGqEYbdpssF/mJJMSC9+CADOL54= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765449049; c=relaxed/simple; bh=Bks6WfBvXZRiysgGfz3X789jvv7vY5FL6+JWgKtcYSg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M9aPgD5bXcnpZl8qHbROQrph0BNfKkdABFIt2rOVFdKU0aiO8v2sX60n6A7f1k8xx8wE9SLA16u3jzGYgRblPYoFKFfsGThoPz/dD5LbaR1jTxI5uwQPFsiswrpzK9NOxgGvVWaEDoriiY0/LphAV0sjXQIUwcVyXaXv8kLiN0A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mmmjU8HQ; 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="mmmjU8HQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44FD1C4CEF7; Thu, 11 Dec 2025 10:30:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765449047; bh=Bks6WfBvXZRiysgGfz3X789jvv7vY5FL6+JWgKtcYSg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mmmjU8HQduSgO2FgbAbsBdbN/TKLyRws1rewY1Xl5dDd/nfYqTvLBv4P3gfDOZH5z luDv6xfcL7sZTUcUhWwE2c2c3edrE+47XfJkQKx0cXcrcKzezIu94uVRdkvhX8SClG j1ke0Igy9iFMgkMgjk6tlwgok30FwrXOIhKfztXn85IqjhQMKCHnN+kXnQoTxiav7r oF3wnV2w+gwgQoJbixCzoy5jOn2Le2wBeWSsAJvYjPL5IKln4xZHWFRySOs96NCrjA EouJtVErzn6M2lUkIfkCSeiBWv2logqd0rC36CYCouYXv3oIP6L1sX1qVvzKNWs5Qp jJQ10oh57lwvw== Date: Thu, 11 Dec 2025 10:30:43 +0000 From: Simon Horman To: Edward Adam Davis Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzbot+5dd615f890ddada54057@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH net v3] net: atm: implement pre_send to check input before sending Message-ID: References: Precedence: bulk X-Mailing-List: netdev@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: On Thu, Dec 11, 2025 at 02:55:45PM +0800, Edward Adam Davis wrote: > On Wed, 10 Dec 2025 13:02:56 +0000, Simon Horman wrote: > > On Wed, Dec 10, 2025 at 06:50:02PM +0800, Edward Adam Davis wrote: > > > Sun, Wed, 10 Dec 2025 10:31:34 +0000, Simon Horman wrote: > > > > > syzbot found an uninitialized targetless variable. The user-provided > > > > > data was only 28 bytes long, but initializing targetless requires at > > > > > least 44 bytes. This discrepancy ultimately led to the uninitialized > > > > > variable access issue reported by syzbot [1]. > > > > > > > > > > Besides the issues reported by syzbot regarding targetless messages > > > > > [1], similar problems exist in other types of messages as well. We will > > > > > uniformly add input data checks to pre_send to prevent uninitialized > > > > > issues from recurring. > > > > > > > > > > Additionally, for cases where sizeoftlvs is greater than 0, the skb > > > > > requires more memory, and this will also be checked. > > > > > > > > > > [1] > > > > > BUG: KMSAN: uninit-value in lec_arp_update net/atm/lec.c:1845 [inline] > > > > > lec_arp_update net/atm/lec.c:1845 [inline] > > > > > lec_atm_send+0x2b02/0x55b0 net/atm/lec.c:385 > > > > > vcc_sendmsg+0x1052/0x1190 net/atm/common.c:650 > > > > > > > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > > > > Reported-by: syzbot+5dd615f890ddada54057@syzkaller.appspotmail.com > > > > > Closes: https://syzkaller.appspot.com/bug?extid=5dd615f890ddada54057 > > > > > Signed-off-by: Edward Adam Davis > > > > > --- > > > > > v3: > > > > > - update coding style and practices > > > > > v2: https://lore.kernel.org/all/tencent_E83074AB763967783C9D36949674363C4A09@qq.com/ > > > > > - update subject and comments for pre_send > > > > > v1: https://lore.kernel.org/all/tencent_B31D1B432549BA28BB5633CB9E2C1B124B08@qq.com > > > > > > > > FTR, a similar patch has been posted by Dharanitharan (CCed) > > > Didn't you check the dates? I released the third version of the patch > > > on December 4th (the first version was on November 28th), while this > > > person above released their first version of the patch on December 7th. > > > Their patch is far too similar to mine! > > > > Yes, I was aware of the timeline when I wrote my previous email. > > > > My preference is for some consensus to be reached on the way forward: > > both technically and in terms of process. > I'm a little confused. Why are you explaining the process to someone > who submitted a patch 99% similar to mine, just a few days after I did? It's always tricky when similar patches are on the ML on the same time. Ultimately what I would like is for a correct solution to be merged. Ideally in a way that makes everyone happy. I'm explaining that to everyone: in this thread, and elsewhere.