From: Pavel Begunkov <asml.silence@gmail.com>
To: lazyming <minhnguyen.080505@gmail.com>, netdev@vger.kernel.org
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, horms@kernel.org, sowmini.varadhan@oracle.com,
willemdebruijn.kernel@gmail.com, w@1wt.eu,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
achender@kernel.org, mst@redhat.com, jasowang@redhat.com,
Willem de Bruijn <willemb@google.com>
Subject: Re: [PATCH net v2] net: skbuff: fix missing zerocopy reference in pskb_carve helpers
Date: Thu, 28 May 2026 19:32:19 +0100 [thread overview]
Message-ID: <5f63fd24-a0da-4623-b449-1e749c3e2085@gmail.com> (raw)
In-Reply-To: <20260526041240.329462-1-minhnguyen.080505@gmail.com>
On 5/26/26 05:12, lazyming wrote:
> From: Minh Nguyen <minhnguyen.080505@gmail.com>
>
> pskb_carve_inside_header() and pskb_carve_inside_nonlinear() both copy
> the old skb_shared_info header into a new buffer via memcpy(), which
> includes the destructor_arg pointer (uarg) for MSG_ZEROCOPY skbs.
> Neither function calls net_zcopy_get() for the new shinfo, creating an
> unaccounted holder: every skb_shared_info with destructor_arg set will
> call skb_zcopy_clear() once when freed, but the corresponding
> net_zcopy_get() was never called for the new copy. Repeated calls
> drive uarg->refcnt to zero prematurely, freeing ubuf_info_msgzc while
> TX skbs still hold live destructor_arg pointers.
A bit late but lgtm
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
--
Pavel Begunkov
prev parent reply other threads:[~2026-05-28 18:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-26 4:12 [PATCH net v2] net: skbuff: fix missing zerocopy reference in pskb_carve helpers lazyming
2026-05-28 11:30 ` patchwork-bot+netdevbpf
2026-05-28 18:32 ` Pavel Begunkov [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5f63fd24-a0da-4623-b449-1e749c3e2085@gmail.com \
--to=asml.silence@gmail.com \
--cc=achender@kernel.org \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=horms@kernel.org \
--cc=jasowang@redhat.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=minhnguyen.080505@gmail.com \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sowmini.varadhan@oracle.com \
--cc=stable@vger.kernel.org \
--cc=w@1wt.eu \
--cc=willemb@google.com \
--cc=willemdebruijn.kernel@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox