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 7D5CE3AB285; Sat, 30 May 2026 17:37:37 +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=1780162661; cv=none; b=FfAcJCZGK7cOn+vZNibrbPG/fPuKEmuBTZ9SiPDaA7qjMP+SdfpCr6NwBQWF88F1Hytse6NXtTiRUKgCaEZTt/h8qcfUkFrqKvKSByZUHHsMlV8pOb3zVBe7dYpgkLs2bftYu2NBkAdlX6S+kLMTYZhFnGIMThW8o1maxMIY7wU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162661; c=relaxed/simple; bh=KlmnENefY+TD59ElbWdUDOOMYJSQxz1a7ROQsnhzXxw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hDJ33n7Sri1hZpDceuqTSMyWDgwLxUKEZRdxyyRutYaMnVxcDM5G0Jeqw+IUFHRvknuhkGUsIi9kbPHlq1SUVweAjjip9FIBStFHLK3DWa+EAZK9J45SrO+vVbdwCETgalrN4uT5/tu6zSdVcs7Je0BOKvM6juTqEaSdrBcC0FA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DTLcVNiI; 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="DTLcVNiI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82C001F00893; Sat, 30 May 2026 17:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162657; bh=J1ooY+hTdNmolOIiuPZXbtzgx0oweXmV6akdCDLVTFI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DTLcVNiIXTFIn7BGVAFbbUkopPEL2VibXvTdrAfTuRL6SuWo/fV+WS4K+sgf7EP3J sCZNNxpjHIH5+RmaRHNBNOPlIHzqiJGiEvmSbASKKNGhoqGmgufWUJy8PKIJqEKbsl GgmKBmGQmZJS/Je+TUOHjklhuxGzMmKLxklXkoPA= 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 5.15 026/776] net: lapbether: handle NETDEV_PRE_TYPE_CHANGE Date: Sat, 30 May 2026 17:55:40 +0200 Message-ID: <20260530160240.942596379@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@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 5.15-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 75613ac26641f..033d8cdde38a3 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -444,33 +444,36 @@ 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