From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3F45B2D0606; Thu, 12 Mar 2026 20:24:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773347089; cv=none; b=uyR0s2FDWczyWN6v35HETIehy8zNfmZuxdZKRpN/Z772ugfJocHEnXczEjRVEPiJ/4Y1u5gOlqXBKQNSEs6kiRiFAFLavrP+vvh1Yz43dsMrAkMZrjPfwp+rt701BzoXdanhZMcNUrltpj8iogYoivJ/FOyJnb6PK9Yx+YZtmv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773347089; c=relaxed/simple; bh=Rk0XJFK3kunHKj74DxTos2CXZrrsVSyIeWDmbnQiC5s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IoO7Psfr0rHPAChZgit0efxVAMIZOh30gaoamLO/LD4UBVKdXBRQebNHlgmUHf6e+udJAeuhY2OtUnt2g8kErVcpIWCPz7XiRpbixU0rRNPBtQ4p0949IXz/BpPqDfIN6KXwTvp7w+rs10wzmOAPskUCS5dqwtlVWtvWGul6wWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M+ZAxevT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="M+ZAxevT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90A12C2BC86; Thu, 12 Mar 2026 20:24:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773347088; bh=Rk0XJFK3kunHKj74DxTos2CXZrrsVSyIeWDmbnQiC5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M+ZAxevT634P+4CX+HhfL4FZBQYCIEb0cHOri2oMVb5BMugdhw0Zx0iFjnkn5k8jE ZDNOKtwKTo7GR8NCQl3pJXVPk+j7ANpzi7gSyFAb8Sj5ZfjQizm2vwYo1hE35uVFQk MLXN9AWSo1EZujmtly3kUzxPpqQyb9yga+v6GJPU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+5a287bcdc08104bc3132@syzkaller.appspotmail.com, Jiayuan Chen , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 200/265] bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded Date: Thu, 12 Mar 2026 21:09:47 +0100 Message-ID: <20260312201025.543281284@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260312201018.128816016@linuxfoundation.org> References: <20260312201018.128816016@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiayuan Chen [ Upstream commit 479d589b40b836442bbdadc3fdb37f001bb67f26 ] bond_option_mode_set() already rejects mode changes that would make a loaded XDP program incompatible via bond_xdp_check(). However, bond_option_xmit_hash_policy_set() has no such guard. For 802.3ad and balance-xor modes, bond_xdp_check() returns false when xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually absent due to hardware offload. This means a user can: 1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode with a compatible xmit_hash_policy (e.g. layer2+3). 2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded. This leaves bond->xdp_prog set but bond_xdp_check() now returning false for the same device. When the bond is later destroyed, dev_xdp_uninstall() calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering: WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL)) Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an XDP program is loaded on a bond in 802.3ad or balance-xor mode. commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") introduced bond_xdp_check() which returns false for 802.3ad/balance-xor modes when xmit_hash_policy is vlan+srcmac. The check was wired into bond_xdp_set() to reject XDP attachment with an incompatible policy, but the symmetric path -- preventing xmit_hash_policy from being changed to an incompatible value after XDP is already loaded -- was left unguarded in bond_option_xmit_hash_policy_set(). Note: commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode") later added a similar guard to bond_option_mode_set(), but bond_option_xmit_hash_policy_set() remained unprotected. Reported-by: syzbot+5a287bcdc08104bc3132@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6995aff6.050a0220.2eeac1.014e.GAE@google.com/T/ Fixes: 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") Signed-off-by: Jiayuan Chen Link: https://patch.msgid.link/20260226080306.98766-2-jiayuan.chen@linux.dev Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/bonding/bond_main.c | 9 +++++++-- drivers/net/bonding/bond_options.c | 2 ++ include/net/bonding.h | 1 + 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index dd1f8cad953bf..2ac455a9d1bb1 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -322,7 +322,7 @@ static bool bond_sk_check(struct bonding *bond) } } -bool bond_xdp_check(struct bonding *bond, int mode) +bool __bond_xdp_check(int mode, int xmit_policy) { switch (mode) { case BOND_MODE_ROUNDROBIN: @@ -333,7 +333,7 @@ bool bond_xdp_check(struct bonding *bond, int mode) /* vlan+srcmac is not supported with XDP as in most cases the 802.1q * payload is not in the packet due to hardware offload. */ - if (bond->params.xmit_policy != BOND_XMIT_POLICY_VLAN_SRCMAC) + if (xmit_policy != BOND_XMIT_POLICY_VLAN_SRCMAC) return true; fallthrough; default: @@ -341,6 +341,11 @@ bool bond_xdp_check(struct bonding *bond, int mode) } } +bool bond_xdp_check(struct bonding *bond, int mode) +{ + return __bond_xdp_check(mode, bond->params.xmit_policy); +} + /*---------------------------------- VLAN -----------------------------------*/ /* In the following 2 functions, bond_vlan_rx_add_vid and bond_vlan_rx_kill_vid, diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c index a37b47b8ea8ed..33af81a55a45f 100644 --- a/drivers/net/bonding/bond_options.c +++ b/drivers/net/bonding/bond_options.c @@ -1546,6 +1546,8 @@ static int bond_option_fail_over_mac_set(struct bonding *bond, static int bond_option_xmit_hash_policy_set(struct bonding *bond, const struct bond_opt_value *newval) { + if (bond->xdp_prog && !__bond_xdp_check(BOND_MODE(bond), newval->value)) + return -EOPNOTSUPP; netdev_dbg(bond->dev, "Setting xmit hash policy to %s (%llu)\n", newval->string, newval->value); bond->params.xmit_policy = newval->value; diff --git a/include/net/bonding.h b/include/net/bonding.h index 9fb40a5920209..66940d41d4854 100644 --- a/include/net/bonding.h +++ b/include/net/bonding.h @@ -696,6 +696,7 @@ void bond_debug_register(struct bonding *bond); void bond_debug_unregister(struct bonding *bond); void bond_debug_reregister(struct bonding *bond); const char *bond_mode_name(int mode); +bool __bond_xdp_check(int mode, int xmit_policy); bool bond_xdp_check(struct bonding *bond, int mode); void bond_setup(struct net_device *bond_dev); unsigned int bond_get_num_tx_queues(void); -- 2.51.0