Netdev List
 help / color / mirror / Atom feed
From: Nicolai Buchwitz <nb@tipi-net.de>
To: "David S. Miller" <davem@davemloft.net>,
	 Eric Dumazet <edumazet@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>,
	 Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
	 Oleksij Rempel <o.rempel@pengutronix.de>,
	 Maxime Chevallier <maxime.chevallier@bootlin.com>,
	 Andrew Lunn <andrew+netdev@lunn.ch>,
	 Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	 Alexandre Torgue <alexandre.torgue@foss.st.com>,
	 Jose Abreu <Jose.Abreu@synopsys.com>,
	Saeed Mahameed <saeedm@nvidia.com>,
	 Tariq Toukan <tariqt@nvidia.com>, Mark Bloch <mbloch@nvidia.com>,
	 Leon Romanovsky <leon@kernel.org>,
	Dragos Tatulea <dtatulea@nvidia.com>,
	 Alexei Lazar <alazar@nvidia.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	 linux-stm32@st-md-mailman.stormreply.com,
	 linux-arm-kernel@lists.infradead.org,
	linux-rdma@vger.kernel.org,  Nicolai Buchwitz <nb@tipi-net.de>
Subject: [PATCH net-next 1/3] net: selftests: use skb_share_check() in the loopback receive hook
Date: Wed, 07 Oct 2026 20:29:22 +0200	[thread overview]
Message-ID: <20261007-nb-net-selftest-shared-net-v1-1-458369bfa1ba@tipi-net.de> (raw)
In-Reply-To: <20261007-nb-net-selftest-shared-net-v1-0-458369bfa1ba@tipi-net.de>

The loopback hook gets a shared skb when another ETH_P_IP handler is
bound to the device. skb_unshare() does not unshare it, so
skb_linearize() on a non-linear frame hits BUG_ON(skb_shared()).

Use skb_share_check() instead.

Fixes: 3e1e58d64c3d ("net: add generic selftest support")
Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
---
 net/core/selftests.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/selftests.c b/net/core/selftests.c
index 36b949ae520b..80029a67b2d2 100644
--- a/net/core/selftests.c
+++ b/net/core/selftests.c
@@ -170,7 +170,7 @@ static int net_test_loopback_validate(struct sk_buff *skb,
 	struct tcphdr *thdr;
 	struct iphdr *ihdr;
 
-	skb = skb_unshare(skb, GFP_ATOMIC);
+	skb = skb_share_check(skb, GFP_ATOMIC);
 	if (!skb)
 		goto out;
 

-- 
2.53.0


  reply	other threads:[~2026-10-07 18:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-07 18:29 [PATCH net-next 0/3] net: use skb_share_check() in loopback selftest hooks Nicolai Buchwitz
2026-10-07 18:29 ` Nicolai Buchwitz [this message]
2026-10-08 21:31   ` [PATCH net-next 1/3] net: selftests: use skb_share_check() in the loopback receive hook netdev-bot+sashiko
2026-10-09  6:49     ` Nicolai Buchwitz
2026-10-09 16:59   ` Simon Horman
2026-10-07 18:29 ` [PATCH net-next 2/3] net: stmmac: " Nicolai Buchwitz
2026-10-09 16:59   ` Simon Horman
2026-10-07 18:29 ` [PATCH net-next 3/3] net/mlx5e: use skb_share_check() in the loopback selftest hook Nicolai Buchwitz
2026-10-08 21:31   ` netdev-bot+sashiko
2026-10-09  8:37     ` Nicolai Buchwitz
2026-10-09 17:00   ` Simon Horman

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=20261007-nb-net-selftest-shared-net-v1-1-458369bfa1ba@tipi-net.de \
    --to=nb@tipi-net.de \
    --cc=Jose.Abreu@synopsys.com \
    --cc=alazar@nvidia.com \
    --cc=alexandre.torgue@foss.st.com \
    --cc=andrew+netdev@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=dtatulea@nvidia.com \
    --cc=edumazet@kernel.org \
    --cc=horms@kernel.org \
    --cc=kuba@kernel.org \
    --cc=leon@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=maxime.chevallier@bootlin.com \
    --cc=mbloch@nvidia.com \
    --cc=mcoquelin.stm32@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=o.rempel@pengutronix.de \
    --cc=pabeni@redhat.com \
    --cc=saeedm@nvidia.com \
    --cc=tariqt@nvidia.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