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 51E2E2D23AD; Mon, 13 Oct 2025 15:32:40 +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=1760369560; cv=none; b=EVlzkq2c5+h2jJY17k5K/Dbk9QruNEk0QMMaROjTRJe/WpaqwAHoBLRw/k/FTcCGkL973JThawQqYSzU+utxrNu/o5FNpEixhAYoic+ukSYRyfd/uNN4+cBPOs2ibA9l2CfR3QdggHj2+sRhe/iFXq9Hm+6LUEdkOXAZLZwBtyU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760369560; c=relaxed/simple; bh=8pfhLcNxJ5L2E9CfaugqBQaaVhBRt72UO8BMHp1gfdw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lWNeE/LtvacAlPTczPMgk0mU3GGJdui3mVnk+wg/JBA6zGadUwGoR7HfGnXsUYSutLO7ej0OGTvejOVZzaHlMQW2uMih0C2J/oni9aZ4tVINsXzk3kpH3Ev5E38jSDykWWSWBRudZZy7hlntn5AZqZJJlpJsg8GMlsKX601NrVQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ARpSf+Qv; 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="ARpSf+Qv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4A9DC4CEFE; Mon, 13 Oct 2025 15:32:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760369560; bh=8pfhLcNxJ5L2E9CfaugqBQaaVhBRt72UO8BMHp1gfdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ARpSf+QvzfeMysQr71Y6vLoMY2stChOt1yKJRKFsfqlN2ggtxAHWG8V4kYDt0mt7Q 6bLFVU1SH+WhEoyO0OFTXmOj5E+f00nj3fg0Q0vLcm9/+5UHflWk2/HWLeQQCZE2Hv qh4nT+7dkfqZt+7y8osq+6JNbm3+QRNarUxgs6rQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.17 289/563] net: use dst_dev_rcu() in sk_setup_caps() Date: Mon, 13 Oct 2025 16:42:30 +0200 Message-ID: <20251013144421.739021790@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@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 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 99a2ace61b211b0be861b07fbaa062fca4b58879 ] Use RCU to protect accesses to dst->dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu(). Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250828195823.3958522-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/ip.h | 6 ++++-- include/net/ip6_route.h | 2 +- include/net/route.h | 2 +- net/core/sock.c | 16 ++++++++++------ 4 files changed, 16 insertions(+), 10 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index befcba575129a..6dbd2bf8fa9c9 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -467,12 +467,14 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, bool forwarding) { const struct rtable *rt = dst_rtable(dst); + const struct net_device *dev; unsigned int mtu, res; struct net *net; rcu_read_lock(); - net = dev_net_rcu(dst_dev(dst)); + dev = dst_dev_rcu(dst); + net = dev_net_rcu(dev); if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || ip_mtu_locked(dst) || !forwarding) { @@ -486,7 +488,7 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, if (mtu) goto out; - mtu = READ_ONCE(dst_dev(dst)->mtu); + mtu = READ_ONCE(dev->mtu); if (unlikely(ip_mtu_locked(dst))) { if (rt->rt_uses_gateway && mtu > 576) diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 9255f21818ee7..59f48ca3abdf5 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -337,7 +337,7 @@ static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst mtu = IPV6_MIN_MTU; rcu_read_lock(); - idev = __in6_dev_get(dst_dev(dst)); + idev = __in6_dev_get(dst_dev_rcu(dst)); if (idev) mtu = READ_ONCE(idev->cnf.mtu6); rcu_read_unlock(); diff --git a/include/net/route.h b/include/net/route.h index 7ea840daa775b..c916bbe25a774 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -390,7 +390,7 @@ static inline int ip4_dst_hoplimit(const struct dst_entry *dst) const struct net *net; rcu_read_lock(); - net = dev_net_rcu(dst_dev(dst)); + net = dst_dev_net_rcu(dst); hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl); rcu_read_unlock(); } diff --git a/net/core/sock.c b/net/core/sock.c index 158bddd23134c..e21348ead7e76 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2584,7 +2584,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) } EXPORT_SYMBOL_GPL(sk_clone_lock); -static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst) +static u32 sk_dst_gso_max_size(struct sock *sk, const struct net_device *dev) { bool is_ipv6 = false; u32 max_size; @@ -2594,8 +2594,8 @@ static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst) !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)); #endif /* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */ - max_size = is_ipv6 ? READ_ONCE(dst_dev(dst)->gso_max_size) : - READ_ONCE(dst_dev(dst)->gso_ipv4_max_size); + max_size = is_ipv6 ? READ_ONCE(dev->gso_max_size) : + READ_ONCE(dev->gso_ipv4_max_size); if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk)) max_size = GSO_LEGACY_MAX_SIZE; @@ -2604,9 +2604,12 @@ static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst) void sk_setup_caps(struct sock *sk, struct dst_entry *dst) { + const struct net_device *dev; u32 max_segs = 1; - sk->sk_route_caps = dst_dev(dst)->features; + rcu_read_lock(); + dev = dst_dev_rcu(dst); + sk->sk_route_caps = dev->features; if (sk_is_tcp(sk)) { struct inet_connection_sock *icsk = inet_csk(sk); @@ -2622,13 +2625,14 @@ void sk_setup_caps(struct sock *sk, struct dst_entry *dst) sk->sk_route_caps &= ~NETIF_F_GSO_MASK; } else { sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM; - sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst); + sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dev); /* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */ - max_segs = max_t(u32, READ_ONCE(dst_dev(dst)->gso_max_segs), 1); + max_segs = max_t(u32, READ_ONCE(dev->gso_max_segs), 1); } } sk->sk_gso_max_segs = max_segs; sk_dst_set(sk, dst); + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(sk_setup_caps); -- 2.51.0