From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C1752E7390; Sat, 30 May 2026 18:20:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165249; cv=none; b=rjIiH2NifMVE7dsvnox3HhlcMWpkhAw0vhJipwaDDUTPc1Mk4NDpi5WPbQCxyZ0k8rjMvBgr9MgR4XmIpdF/ll5MFBMoXQWIwEleVfhtgZrMUZImpmr/dAkip0FGyC60U4B07wcub4g8TJGaDqtr6nAO93Xo905gNB6Y4UNdRVk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165249; c=relaxed/simple; bh=aCjLP4SmTPZ7/LeWCyQDLLvynP79bKGEQh/2SXNKwrY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hr5E9PS9S/4EZaUgvrmOY3CnqrQqZYw45JRslztdZRbEN1TvF+PPAy74xzhrhGih9uLVSrK5/bySgHIM/oujv+YIFAZh7AcEsIj9r0YvOpwj4kdP+AMxK5qiWg8CvA8OkYlEXYqP2iFK/i/ImNvx7rxkoHRjNSWtQZuplKRKV+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SA+dMWuw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SA+dMWuw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 909DD1F00893; Sat, 30 May 2026 18:20:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780165248; bh=AEZ75mu+MtqTTj406sbQGkF13TB9lWghSms0AMOxtao=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SA+dMWuw8JVRC+5KxTCOz/vdHcbtuRnT451BLfcWGKA9++ygtW6FE2kLUoJT2WY3K DMX3z/iS6BClYmKyHr6q4CY5gLQY2Za1PyS5cNO8yhE/Dv2M3Zg0EivD2kteKOIy55 nFxWIdSQIHEh1Kx+xh1nQ9Rvticn3dTLrDMONy5Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+d8c285748fa7292580a9@syzkaller.appspotmail.com, Eric Dumazet , Martin Schiller , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 023/589] net: lapbether: handle NETDEV_PRE_TYPE_CHANGE Date: Sat, 30 May 2026 17:58:24 +0200 Message-ID: <20260530160225.191575682@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit b120e4432f9f56c7103133d6a11245e617695adb ] lapbeth_data_transmit() expects the underlying device type to be ARPHRD_ETHER. Returning NOTIFY_BAD from lapbeth_device_event() makes sure bonding driver can not break this expectation. Fixes: 872254dd6b1f ("net/bonding: Enable bonding to enslave non ARPHRD_ETHER") Reported-by: syzbot+d8c285748fa7292580a9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/69cd22a1.050a0220.70c3a.0002.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Martin Schiller Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260402103519.1201565-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/wan/lapbether.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index 4f89693313175..dd300179dcc56 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -400,33 +400,36 @@ static void lapbeth_free_device(struct lapbethdev *lapbeth) static int lapbeth_device_event(struct notifier_block *this, unsigned long event, void *ptr) { - struct lapbethdev *lapbeth; struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct lapbethdev *lapbeth; if (dev_net(dev) != &init_net) return NOTIFY_DONE; - if (!dev_is_ethdev(dev) && !lapbeth_get_x25_dev(dev)) + lapbeth = lapbeth_get_x25_dev(dev); + if (!dev_is_ethdev(dev) && !lapbeth) return NOTIFY_DONE; switch (event) { case NETDEV_UP: /* New ethernet device -> new LAPB interface */ - if (!lapbeth_get_x25_dev(dev)) + if (!lapbeth) lapbeth_new_device(dev); break; case NETDEV_GOING_DOWN: /* ethernet device closes -> close LAPB interface */ - lapbeth = lapbeth_get_x25_dev(dev); if (lapbeth) dev_close(lapbeth->axdev); break; case NETDEV_UNREGISTER: /* ethernet device disappears -> remove LAPB interface */ - lapbeth = lapbeth_get_x25_dev(dev); if (lapbeth) lapbeth_free_device(lapbeth); break; + case NETDEV_PRE_TYPE_CHANGE: + /* Our underlying device type must not change. */ + if (lapbeth) + return NOTIFY_BAD; } return NOTIFY_DONE; -- 2.53.0