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 04845333725; Mon, 6 Apr 2026 16:08:30 +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=1775491711; cv=none; b=qRYF9ddwle5fg+oESqOUusR6WoLU1bIuZMj1ZtdhH+pd2TXugPzXkM7DiTKd4DhPHvyf3laGZkpwnsheANmz6EVlX5KPDub9EYtgZJQc3uCSkZnU62S0DNdmJ2f0Pc3LDvywho7H10wbARbbipCOiZZFaw2RVhsKxZdPHnt2uFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775491711; c=relaxed/simple; bh=VVxFoFjG/viRylOKdJE72jCsFfLi8SfWOjDNLB6ndq8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Y+v+/cFC8zitFsA97auYUgXja0GCQhmGZeeTERafecvr+maHwzbJ75mKY+uxaRC8fo+r9MkWHVVRSQnRRG31sco+xZdfpT5SIDbKp4b7slPTRMMzmXVv6jdBDZ5aPKx6nUedojO437ylPNz/HfWAUU+H0FqEuzyuZKTxfiys0OI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tt58F5K+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="tt58F5K+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B538C4CEF7; Mon, 6 Apr 2026 16:08:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775491710; bh=VVxFoFjG/viRylOKdJE72jCsFfLi8SfWOjDNLB6ndq8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tt58F5K+XO8W5bz/+zz9ZiD0d2HDiXubM0HxePDecMmVR0N7BtK9Qi1gq3/dwCXe/ l2HCBhXbag3dlcxqLtMazj8unsIKEJliGvvriHE5LM4y0W1C8nkIPl+GMYCJy1layO tNPowgE6Vg98BxfvV6SDo3t4iuTNY7lGscvYWyYI= Date: Mon, 6 Apr 2026 18:08:27 +0200 From: Greg Kroah-Hartman To: Jakub Kicinski Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Steffen Klassert , Herbert Xu , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman Subject: Re: [PATCH net] xfrm_user: fix info leak in build_mapping() Message-ID: <2026040634-deodorant-shakiness-a64e@gregkh> References: <2026040602-shack-tamale-d8c3@gregkh> <20260406085449.266466ae@kernel.org> <20260406085859.2e9843ea@kernel.org> 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: <20260406085859.2e9843ea@kernel.org> On Mon, Apr 06, 2026 at 08:58:59AM -0700, Jakub Kicinski wrote: > On Mon, 6 Apr 2026 08:54:49 -0700 Jakub Kicinski wrote: > > > Note, I think this is correct, as I don't think a new skb has it's > > > fields pre-zeroed out, or am I totally wrong here? > > > > You're right, skb owner is responsible for clearing after put. > > Tho, Netlink is not as perf critical as real networking, I wish > > we at least had a helper which reserves the space and clears it :/ > > This is not the first or the second time we hit this sort of a bug. > > We could make nlmsg_append() do that. Mostly because I don't have > a better idea for a name and nlmsg_append is only used once ;) As shown in my other patch: https://lore.kernel.org/r/2026040621-poison-gristle-aaa3@gregkh we need this in at least 2 places, don't know if it's worth doing it for all messages? I guess nlmsg_append() would work? It tries to do some zeroing out for alignment for some reason... Want me to do that? I don't have a way to test any of this, I just found it using some static code analysis tools that looked at holes in structures. thanks, greg k-h