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 1CF933909A4; Tue, 25 Aug 2026 13:45:49 +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=1787665550; cv=none; b=XGrd+ngRd0Pm2cXN4PHShhCD74i/FhGojazH6+Z1FVGYbeOR3r6sewy3sowZaVFCuFWpcRby72CTAeqCASePGNC2BCm/XuWtcX07kc67cgIteN4PWbR5qUAfhjEv7F7w0gecvhnQUwvmca4RLyhcTBrfyyHMlbwj3WGN6bpG580= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787665550; c=relaxed/simple; bh=ldoeP9x4Ci8Vxop5OfguEBPYLOYv6/rVY+lJciijb2g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=orklJSqoztPKxIw7/SrRDq4+Vy5+iPhEcFI18HDL/6WcHlt86cYRoTo1n8/mEBDRGtoTJMJUqTMHxtdMIBPiXsM3QtjHZjUI5xtJs7S/nHLlYoBjt0dd8xrCvHdH9wfKjp/sJkoG8ngSavhnnzTln2NFTJRfOjQ9N7cyUeLg7fY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OQa4R26E; 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="OQa4R26E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BF651F000E9; Tue, 25 Aug 2026 13:45:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787665548; bh=oKFcsSLk9fwcOIOti5VN2fUcpt+QUqoKyNhAppBkMbI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OQa4R26EyWRPrC991tZCgHPcrLWIsn0T9/S0yA5QY88+X1ZySnMpyuf6oZGKA/qAA JaJ1DSYKxCmt9jg75FI19Ar6mGYsZ8EsFGVBC05QTMg8AXpx4UES7CZ3cksefMKco6 pidkIV2VIarzeyO3AyqzTOfdpP1mkcCfKrhXuWeY= 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 6.12 64/77] ipv4: start using dst_dev_rcu() Date: Tue, 25 Aug 2026 15:26:26 +0200 Message-ID: <20260825132544.045268846@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.580275153@linuxfoundation.org> References: <20260825132541.580275153@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8 ] Change icmpv4_xrlim_allow(), ip_defrag() to prevent possible UAF. Change ipmr_prepare_xmit(), ipmr_queue_fwd_xmit(), ip_mr_output(), ipv4_neigh_lookup() to use lockdep enabled dst_dev_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/20250828195823.3958522-9-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/icmp.c | 6 +++--- net/ipv4/ip_fragment.c | 6 ++++-- net/ipv4/ipmr.c | 2 +- net/ipv4/route.c | 4 ++-- 4 files changed, 10 insertions(+), 8 deletions(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index c7af8b914e13c..1fc967a60bb9c 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -320,17 +320,17 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, return true; /* No rate limit on loopback */ - dev = dst_dev(dst); + rcu_read_lock(); + dev = dst_dev_rcu(dst); if (dev && (dev->flags & IFF_LOOPBACK)) goto out; - rcu_read_lock(); peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, l3mdev_master_ifindex_rcu(dev)); rc = inet_peer_xrlim_allow(peer, READ_ONCE(net->ipv4.sysctl_icmp_ratelimit)); - rcu_read_unlock(); out: + rcu_read_unlock(); if (!rc) __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITHOST); else diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 5825aa8eac7fd..9cc55a0c64f7d 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -470,14 +470,16 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb, /* Process an incoming IP datagram fragment. */ int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) { - struct net_device *dev = skb->dev ? : skb_dst_dev(skb); - int vif = l3mdev_master_ifindex_rcu(dev); + struct net_device *dev; struct ipq *qp; + int vif; __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS); /* Lookup (or create) queue header */ rcu_read_lock(); + dev = skb->dev ? : skb_dst_dev_rcu(skb); + vif = l3mdev_master_ifindex_rcu(dev); qp = ip_find(net, ip_hdr(skb), user, vif); if (qp) { int ret, refs = 0; diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index de0d9cc7806a1..f0294b1148246 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1894,7 +1894,7 @@ static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt, goto out_free; } - dev = rt->dst.dev; + dev = dst_dev_rcu(&rt->dst); if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) { /* Do not fragment multicasts. Alas, IPv4 does not diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 28d83b3baae3b..9135a9dc8f297 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -413,11 +413,11 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr) { const struct rtable *rt = container_of(dst, struct rtable, dst); - struct net_device *dev = dst_dev(dst); + struct net_device *dev; struct neighbour *n; rcu_read_lock(); - + dev = dst_dev_rcu(dst); if (likely(rt->rt_gw_family == AF_INET)) { n = ip_neigh_gw4(dev, rt->rt_gw4); } else if (rt->rt_gw_family == AF_INET6) { -- 2.53.0