netdev - Re: [PATCH net-next 0/4] u64_stats: Introduce u64_stats

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: <20260121111635.GA447040@shredder>
Date: Wed, 21 Jan 2026 13:16:35 +0200
From: Ido Schimmel <idosch@...dia.com>
To: David Yang <mmyangfl@...il.com>
Cc: netdev@...r.kernel.org, Sabrina Dubroca <sd@...asysnail.net>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Nikolay Aleksandrov <razor@...ckwall.org>,
	Simon Horman <horms@...nel.org>, Mark Bloch <mbloch@...dia.com>,
	Petr Machata <petrm@...dia.com>,
	Stanislav Fomichev <sdf@...ichev.me>,
	Carolina Jubran <cjubran@...dia.com>,
	Breno Leitao <leitao@...ian.org>,
	Shigeru Yoshida <syoshida@...hat.com>, linux-kernel@...r.kernel.org,
	bridge@...ts.linux.dev
Subject: Re: [PATCH net-next 0/4] u64_stats: Introduce u64_stats_copy()

On Tue, Jan 20, 2026 at 05:21:28PM +0800, David Yang wrote:
> On 64bit arches, struct u64_stats_sync is empty and provides no help
> against load/store tearing. memcpy() should not be considered atomic
> against u64 values. Use u64_stats_copy() instead.

The existing memcpy() does seem problematic (even if in practice it's
not) and the proposed solution in patch #1 seems OK to me given that all
the callers only pass structures containing 64 bit counters. Couldn't
find any more instances of this pattern.

Reviewed-by: Ido Schimmel <idosch@...dia.com>