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 78B3F43F0AA; Mon, 31 Aug 2026 13:59:22 +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=1788184763; cv=none; b=JMmwh8Xcbs3zPJxCwyLKwnhrqnaPr17krY2HHELM5oYDwtD+yDVYoJmXGj6e8FOcuyeF3k6thlZ7+KkYJVuTZd6NnoxPOqKPTCETnRVFYkVsimk1nrQkwnXGhD9nOEvoxdmcre3xr/tvPAWcdo2gInCwOA7E990uddwLdNzbX5g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788184763; c=relaxed/simple; bh=e4OtwnTV+qlWIAdAl6xS0yt/etYJt+d0ZvNZAgl76dY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=chfwkqJREHO50dgaWEc8ram71Qg3p63QLVLhbTUyVYNkLJd1F/2oLL1DLfBiZIklnxHdLc50adQnmJvic/dqmhih/2fvpzDssO3G2CGu8kdKouxxVJ5gGIQJC/ddDDoaQqxTCtsxhuxaxkSYvEbgZ7DTCnIqCC0qSZ7hVZavyDI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cmY/Lt9B; 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="cmY/Lt9B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C75EC1F00A3D; Mon, 31 Aug 2026 13:59:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788184762; bh=n9K88iOsK/56RbcMpJT+QWC0PV1+sJSnIOKtQUUW1nA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cmY/Lt9Bda70AW2L4Lyz1a/JpJOxjHnaYqfP26u7JTdTOqn5vXDWqV83U/jB+WZue EGu/hc1ZrFv6kRNu00zwhdY5VGXwOmiN2PO+OggC3LvAw1nKTphevhT6NK7kwOAAJk ydIA+trJtCx43hRpLBRF13fGRacGlJ4lswCxOd5g= 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 6.1 30/92] smc: Use __sk_dst_get() and dst_dev_rcu() in smc_vlan_by_tcpsk(). Date: Mon, 31 Aug 2026 15:34:28 +0200 Message-ID: <20260831133401.260305754@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.482388899@linuxfoundation.org> References: <20260831133359.482388899@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 6.1-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 448b7bdf54be2..03bda76fb16b0 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1786,35 +1786,32 @@ 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