netdev - Re: [PATCH v2 0/4] bugfix: Introduce sendpages_ok() to check sendpage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240605072742.GA16306@lst.de>
Date: Wed, 5 Jun 2024 09:27:42 +0200
From: Christoph Hellwig <hch@....de>
To: Jakub Kicinski <kuba@...nel.org>
Cc: Christoph Hellwig <hch@....de>, Ofir Gal <ofir.gal@...umez.com>,
	davem@...emloft.net, linux-block@...r.kernel.org,
	linux-nvme@...ts.infradead.org, netdev@...r.kernel.org,
	ceph-devel@...r.kernel.org, dhowells@...hat.com,
	edumazet@...gle.com, pabeni@...hat.com, kbusch@...nel.org,
	axboe@...nel.dk, sagi@...mberg.me, philipp.reisner@...bit.com,
	lars.ellenberg@...bit.com, christoph.boehmwalder@...bit.com,
	idryomov@...il.com, xiubli@...hat.com
Subject: Re: [PATCH v2 0/4] bugfix: Introduce sendpages_ok() to check
 sendpage_ok() on contiguous pages

On Tue, Jun 04, 2024 at 07:42:24AM -0700, Jakub Kicinski wrote:
> I'd guess the thinking was that if we push back the callers would
> switch the relevant allocations to be page-backed. But we can add
> a comment above the helper that says "you'd be better off using
> page frags and calling sendmsg(MSG_SPLICE_PAGES) directly".

That's just not how network block devices or file systems work, they
don't control the allocations and need to take what gets fed to them.