From: Guillaume Nault <gnault@redhat.com> stable inclusion from stable-v6.6.81 commit 661c63cb34cf8dedc01bfec3caa8dd1da2f5778e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15230 CVE: CVE-2026-45905 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ] Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input() to consider are: * input_action_end_dx4_finish() and input_action_end_dt4() in net/ipv6/seg6_local.c. These functions set the tos parameter to 0, which is already a valid dscp_t value, so they don't need to be adjusted for the new prototype. * icmp_route_lookup(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(), which get the DSCP directly from IPv4 headers. Define a helper to read the .tos field of struct iphdr as dscp_t, so that these function don't have to do the conversion manually. While there, declare *iph as const in br_nf_pre_routing_finish(), declare its local variables in reverse-christmas-tree order and move the "err = ip_route_input()" assignment out of the conditional to avoid checkpatch warning. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- include/net/ip.h | 5 +++++ include/net/route.h | 5 +++-- net/bridge/br_netfilter_hooks.c | 8 +++++--- net/ipv4/icmp.c | 2 +- net/ipv4/ip_options.c | 3 ++- net/ipv6/ip6_tunnel.c | 4 ++-- 6 files changed, 18 insertions(+), 9 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index 2fa407767f33..51117dcac303 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -415,6 +415,11 @@ int ip_decrease_ttl(struct iphdr *iph) return --iph->ttl; } +static inline dscp_t ip4h_dscp(const struct iphdr *ip4h) +{ + return inet_dsfield_to_dscp(ip4h->tos); +} + static inline int ip_mtu_locked(const struct dst_entry *dst) { const struct rtable *rt = (const struct rtable *)dst; diff --git a/include/net/route.h b/include/net/route.h index 25e61f392633..14e074d50cf4 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -194,12 +194,13 @@ int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src, const struct sk_buff *hint); static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, - u8 tos, struct net_device *devin) + dscp_t dscp, struct net_device *devin) { int err; rcu_read_lock(); - err = ip_route_input_noref(skb, dst, src, tos, devin); + err = ip_route_input_noref(skb, dst, src, inet_dscp_to_dsfield(dscp), + devin); if (!err) { skb_dst_force(skb); if (!skb_dst(skb)) diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 8ca424dc5b15..e6962d693359 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -366,9 +366,9 @@ br_nf_ipv4_daddr_was_changed(const struct sk_buff *skb, */ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { - struct net_device *dev = skb->dev, *br_indev; - struct iphdr *iph = ip_hdr(skb); struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); + struct net_device *dev = skb->dev, *br_indev; + const struct iphdr *iph = ip_hdr(skb); struct rtable *rt; int err; @@ -386,7 +386,9 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_ } nf_bridge->in_prerouting = 0; if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) { - if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { + err = ip_route_input(skb, iph->daddr, iph->saddr, + ip4h_dscp(iph), dev); + if (err) { struct in_device *in_dev = __in_dev_get_rcu(dev); /* If err equals -EHOSTUNREACH the error is due to a diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index b2f396126a51..c59ca4fa9d9b 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -557,7 +557,7 @@ static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, orefdst = skb_in->_skb_refdst; /* save old refdst */ skb_dst_set(skb_in, NULL); err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, - inet_dscp_to_dsfield(dscp), rt2->dst.dev); + dscp, rt2->dst.dev); dst_release(&rt2->dst); rt2 = skb_rtable(skb_in); diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 90b55384700e..95d3c39ac072 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -621,7 +621,8 @@ int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev) orefdst = skb->_skb_refdst; skb_dst_set(skb, NULL); - err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, dev); + err = ip_route_input(skb, nexthop, iph->saddr, ip4h_dscp(iph), + dev); rt2 = skb_rtable(skb); if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) { skb_dst_drop(skb); diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index b006e61e776a..5a2583a82f97 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -633,8 +633,8 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, } skb_dst_set(skb2, &rt->dst); } else { - if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, - skb2->dev) || + if (ip_route_input(skb2, eiph->daddr, eiph->saddr, + ip4h_dscp(eiph), skb2->dev) || skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6) goto out; } -- 2.43.0