netdev - Re: [PATCH net] Revert "net: macsec: use skb_ensure_writable_head

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 for Android: free password hash cracker in your pocket

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

Date: Tue, 16 Jan 2024 11:39:35 +0100
From: Paolo Abeni <pabeni@...hat.com>
To: Rahul Rameshbabu <rrameshbabu@...dia.com>, netdev@...r.kernel.org
Cc: Gal Pressman <gal@...dia.com>, Eric Dumazet <edumazet@...gle.com>, Jakub
 Kicinski <kuba@...nel.org>, Radu Pirea <radu-nicolae.pirea@....nxp.com>,
 "David S . Miller" <davem@...emloft.net>, Sabrina Dubroca
 <sd@...asysnail.net>
Subject: Re: [PATCH net] Revert "net: macsec: use
 skb_ensure_writable_head_tail to expand the skb"

On Sun, 2024-01-14 at 09:42 -0800, Rahul Rameshbabu wrote:
> This reverts commit b34ab3527b9622ca4910df24ff5beed5aa66c6b5.
> 
> Using skb_ensure_writable_head_tail without a call to skb_unshare causes
> the MACsec stack to operate on the original skb rather than a copy in the
> macsec_encrypt path. This causes the buffer to be exceeded in space, and
> leads to warnings generated by skb_put operations. 

This part of the changelog is confusing to me. It looks like the skb
should be uncloned under the same conditions before and after this
patch (and/or the reverted)??!

Possibly dev->needed_headroom/needed_tailroom values are incorrect?!?

Thanks!

Paolo