From nobody Sat Sep 26 11:02:29 2026 Received: from mta0.migadu.com (out-132.mta0.migadu.com [91.218.175.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96738386562 for ; Wed, 2 Sep 2026 05:21:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.132 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788326501; cv=none; b=cALdCpu2Sr/1rIB+OwCNYLYUd+NgKFrXBj7rBb5ghFKgz8Gl5fH1FqFVZFufedUf8KZWZC+oifhiO3AhCSKuJ58FnyW5WgyA3Kof27MQfsHZVI+v27dZ3I70e0fiP86147sjAY4qEYL0DMUg7cPIW7H5IWRsugBA3odboLDqMWg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788326501; c=relaxed/simple; bh=f6+f493aMYuc/Qg8lsOD/q9BpPs3SvnuHJTjLCHX4XQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=rhVV9z3M2tN0knruwDnVvjZYzTjpqvqIGk4q+1MPKvuldJYc5VrVT/qggdORvLJwwY1QApkW2BJP8vWIvV+0CkUWfUg0lPHV62Ld6w/HCtZKGYeJDhaR+mHJ9Y60ulQn44uLcHE1a1US48jg3ebO8rDqJ7KS83GwFe3xyTnI7CA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=i8n4E1RF; arc=none smtp.client-ip=91.218.175.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="i8n4E1RF" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=f6+f493aMYuc/Qg8lsOD/q9BpPs3SvnuHJTjLCHX4XQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788326495; v=1; x=1788931295; b=i8n4E1RFiOkpMJA4E1S38TnIfXJiMDdb8PG5o1mfp8Qimh4id2WL2NSkCqY/mC0Sm2UL2JzI u/f0XEyoPKsaPIUHo5GsdEs0dQNDiYabxVRXRqEoDeNIuX23bMFxqTAKzyNkAYCZrtY9ofkDFh1 Nzv1+m/Us69YIPfB/D++6bFQ= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 92b0b4cd37434ed7; Wed, 02 Sep 2026 05:21:25 +0000 X-Mizu-Trace-ID: 92b0b4cd37434ed7 X-Migadu-Flow: FLOW_OUT From: Hangbin Liu Date: Wed, 02 Sep 2026 13:21:12 +0800 Subject: [PATCH net] bonding: fix slave_cnt leak on XDP error paths Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260902-bond_slave_cnt-v1-1-36e95bf4a6ff@kylinos.cn> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQqAIBBA0avIrBNMqKyrRITZVAMxhoYE4d2Tl m/x/wsRA2GEQbwQMFEkzwV1JcAdlneUtBaDVrpVRnVy8bzO8bQJZ8e3NAY745pN2aWHEl0BN3r +4QiMN0w5f0gzaW9lAAAA X-Change-ID: 20260807-bond_slave_cnt-88e78c5f0ab9 To: Jay Vosburgh , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Daniel Borkmann , Jussi Maki Cc: Hangbin Liu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Hangbin Liu X-Mailer: b4 0.14.3 From: Hangbin Liu When bond_enslave() succeeds up to the XDP setup stage, slave_cnt is already incremented. If XDP setup subsequently fails, the error paths jump directly to err_sysfs_del, bypassing the slave_cnt decrement. This causes slave_cnt to drift upward on each failed enslaving attempt, which would lead to unbalanced traffic distribution with round-robin and balance-xor mode. Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver") Signed-off-by: Hangbin Liu --- drivers/net/bonding/bond_main.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_mai= n.c index 947d92a669b6..0305a017e327 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2305,7 +2305,7 @@ int bond_enslave(struct net_device *bond_dev, struct = net_device *slave_dev, SLAVE_NL_ERR(bond_dev, slave_dev, extack, "Slave does not support XDP"); res =3D -EOPNOTSUPP; - goto err_sysfs_del; + goto err_slave_cnt; } } else if (bond->xdp_prog) { struct netdev_bpf xdp =3D { @@ -2319,14 +2319,14 @@ int bond_enslave(struct net_device *bond_dev, struc= t net_device *slave_dev, SLAVE_NL_ERR(bond_dev, slave_dev, extack, "Slave has XDP program loaded, please unload before enslaving"); res =3D -EOPNOTSUPP; - goto err_sysfs_del; + goto err_slave_cnt; } =20 res =3D dev_xdp_propagate(slave_dev, &xdp); if (res < 0) { /* ndo_bpf() sets extack error message */ slave_dbg(bond_dev, slave_dev, "Error %d calling ndo_bpf\n", res); - goto err_sysfs_del; + goto err_slave_cnt; } if (bond->xdp_prog) bpf_prog_inc(bond->xdp_prog); @@ -2348,6 +2348,9 @@ int bond_enslave(struct net_device *bond_dev, struct = net_device *slave_dev, return 0; =20 /* Undo stages on error */ +err_slave_cnt: + WRITE_ONCE(bond->slave_cnt, bond->slave_cnt - 1); + err_sysfs_del: bond_sysfs_slave_del(new_slave); =20 --- base-commit: 70f3995830d3f1e79faa14eb0605914f778feca9 change-id: 20260807-bond_slave_cnt-88e78c5f0ab9 Best regards, --=20 Hangbin Liu