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 @@ -548,26 +548,27 @@ static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, unsigned long orefdst; fl4_2.daddr = fl4_dec.saddr; rt2 = ip_route_output_key(net, &fl4_2); if (IS_ERR(rt2)) { err = PTR_ERR(rt2); 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) goto relookup_failed; rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, flowi4_to_flowi(&fl4_dec), NULL, XFRM_LOOKUP_ICMP); if (!IS_ERR(rt2)) { 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 @@ -613,26 +613,25 @@ int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev) return -EINVAL; for (srrptr = optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) { if (srrptr + 3 > srrspace) { icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24)); return -EINVAL; } 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); if (rt2->rt_type != RTN_LOCAL) break; /* Superfast 8) loopback forward */ iph->daddr = nexthop; opt->is_changed = 1; } -- 2.43.0