From: Stanislav Fomichev <sdf@fomichev.me> stable inclusion from stable-v6.6.128 commit d621dd67a72d46a3f5329dbea8f8368228d4a3d7 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 e97e6a1830ddb5885ba312e56b6fa3aa39b5f47e ] Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dstref_steal is added to reset existing entry without doing refcnt. skb_dstref_restore should be used to restore the previous entry. Convert icmp_route_lookup and ip_options_rcv_srr to these helpers. Add extra call to skb_dstref_reset to icmp_route_lookup to clear the ip_route_input entry. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250818154032.3173645-5-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 81b84de32bb2 ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/ipv4/icmp.c | 7 ++++--- net/ipv4/ip_options.c | 5 ++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index c59ca4fa9d9b..837f93a34ff0 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -554,14 +554,15 @@ static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, goto relookup_failed; } /* Ugh! */ - orefdst = skb_in->_skb_refdst; /* save old refdst */ - skb_dst_set(skb_in, NULL); + orefdst = skb_dstref_steal(skb_in); err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, dscp, rt2->dst.dev); dst_release(&rt2->dst); rt2 = skb_rtable(skb_in); - skb_in->_skb_refdst = orefdst; /* restore old refdst */ + /* steal dst entry from skb_in, don't drop refcnt */ + skb_dstref_steal(skb_in); + skb_dstref_restore(skb_in, orefdst); } if (err) diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 95d3c39ac072..7a60bbf4bee3 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -619,14 +619,13 @@ int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev) } memcpy(&nexthop, &optptr[srrptr-1], 4); - orefdst = skb->_skb_refdst; - skb_dst_set(skb, NULL); + orefdst = skb_dstref_steal(skb); 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); - skb->_skb_refdst = orefdst; + skb_dstref_restore(skb, orefdst); return -EINVAL; } refdst_drop(orefdst); -- 2.43.0