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 B170A4854EE; Mon, 31 Aug 2026 14:03:04 +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=1788184986; cv=none; b=YxH2gakd8BAV7kJYDG/qhZ4R5R4zWo/UROyHBgbUnJUhZ8Y8ZXnpnLVgSc27Ka8ICFyho+LICaQuB0DufvbmAw7fEj8+cj/xszYJi2eKGEBmvDi/YkxgLqPYaV9QwX8wR161uGz+whvkIOCzTn52eVzTspFG4aIUqs8yNi+MCTM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788184986; c=relaxed/simple; bh=WgI97qG/4aAe6QnS2SjqS4jof0VVm+VE8fNWOEg1ygU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ih2HRc/YETldyKAElPsCaeqGx2MGbK41SdlQfsaD2TTAqaMdeUVBjJokLwPnQ9yqNaLzckE+1bRukft6HVyb6R64ti9a1ZmqKJ3LPeh4myI6ho5748XE6Gs/4642H9e7Ok9QKUVxx9rXe2S00qPAT7tCPO5jC+9wSUCTuyEu7yQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hfHSH5uH; 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="hfHSH5uH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 177261F00A3D; Mon, 31 Aug 2026 14:03:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788184984; bh=P9tsM3r8KVbBHVmasyECK0ie2e1oMEBrpjALWusjAYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hfHSH5uHZCl20wgUA80IhvKXYcIdwZLfxRmZViqtg0nDKvhiEm/EDH4CYcBxpX8t1 PUNlADPh/0lySphHpICLSKFEFCBOeWZI/uxL4kptNIzerc4GxH7APwMSz7Lrk/HcD/ IEf9Ex6EW2mEdMU+yVAGRXaiK1a+iy3jIZxkCjr0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 14/69] smc: Use __sk_dst_get() and dst_dev_rcu() in smc_vlan_by_tcpsk(). Date: Mon, 31 Aug 2026 15:34:47 +0200 Message-ID: <20260831133359.195944015@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133358.601894154@linuxfoundation.org> References: <20260831133358.601894154@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: Kuniyuki Iwashima [ Upstream commit 0b0e4d51c6554e5ecc3f8cc73c2eaf12da21249a ] smc_vlan_by_tcpsk() fetches sk_dst_get(sk)->dev before RTNL and passes it to netdev_walk_all_lower_dev(), which is illegal. Also, smc_vlan_by_tcpsk_walk() does not require RTNL at all. Let's use __sk_dst_get(), dst_dev_rcu(), and netdev_walk_all_lower_dev_rcu(). Note that the returned value of smc_vlan_by_tcpsk() is not used in the caller. Fixes: 0cfdd8f92cac ("smc: connection and link group creation") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250916214758.650211-5-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/smc/smc_core.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 37614dcf19194..f6119f29b44ce 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1612,35 +1612,32 @@ static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev, /* Determine vlan of internal TCP socket. */ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini) { - struct dst_entry *dst = sk_dst_get(clcsock->sk); struct netdev_nested_priv priv; struct net_device *ndev; + struct dst_entry *dst; int rc = 0; ini->vlan_id = 0; - if (!dst) { - rc = -ENOTCONN; - goto out; - } - if (!dst->dev) { + + rcu_read_lock(); + + dst = __sk_dst_get(clcsock->sk); + ndev = dst ? dst_dev_rcu(dst) : NULL; + if (!ndev) { rc = -ENODEV; - goto out_rel; + goto out; } - ndev = dst->dev; if (is_vlan_dev(ndev)) { ini->vlan_id = vlan_dev_vlan_id(ndev); - goto out_rel; + goto out; } priv.data = (void *)&ini->vlan_id; - rtnl_lock(); - netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv); - rtnl_unlock(); - -out_rel: - dst_release(dst); + netdev_walk_all_lower_dev_rcu(ndev, smc_vlan_by_tcpsk_walk, &priv); out: + rcu_read_unlock(); + return rc; } -- 2.53.0