From: Pablo Neira Ayuso <pablo@netfilter.org> stable inclusion from stable-v6.6.134 commit a76157a1eee5f8a18c16809656c698a05ca6bf9d category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14557 CVE: CVE-2026-43025 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 02a3231b6d82efe750da6554ebf280e4a6f78756 ] __nf_ct_expect_find() and nf_ct_expect_find_get() are called under rcu_read_lock() but they dereference the master conntrack via exp->master. Since the expectation does not hold a reference on the master conntrack, this could be dying conntrack or different recycled conntrack than the real master due to SLAB_TYPESAFE_RCU. Store the netns, the master_tuple and the zone in struct nf_conntrack_expect as a safety measure. This patch is required by the follow up fix not to dump expectations that do not belong to this netns. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Stable-dep-of: 917b61fa2042 ("netfilter: ctnetlink: ignore explicit helper on new expectations") Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: net/netfilter/nf_conntrack_expect.c [commit bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 ("netfilter: ctnetlink: ensure safe access to master conntrack") introduced lockdep_nfct_expect_lock_held() before nf_ct_remove_expect(), which is not present in the target branch. Adapted hunk context manually to preserve the existing lockdep call.] Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- include/net/netfilter/nf_conntrack_expect.h | 18 +++++++++++++++++- net/netfilter/nf_conntrack_broadcast.c | 6 +++++- net/netfilter/nf_conntrack_expect.c | 9 +++++++-- net/netfilter/nf_conntrack_netlink.c | 5 +++++ 4 files changed, 34 insertions(+), 4 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h index 1b01400b10bd..e9a8350e7ccf 100644 --- a/include/net/netfilter/nf_conntrack_expect.h +++ b/include/net/netfilter/nf_conntrack_expect.h @@ -22,10 +22,16 @@ struct nf_conntrack_expect { /* Hash member */ struct hlist_node hnode; + /* Network namespace */ + possible_net_t net; + /* We expect this tuple, with the following mask */ struct nf_conntrack_tuple tuple; struct nf_conntrack_tuple_mask mask; +#ifdef CONFIG_NF_CONNTRACK_ZONES + struct nf_conntrack_zone zone; +#endif /* Usage count. */ refcount_t use; @@ -62,7 +68,17 @@ struct nf_conntrack_expect { static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp) { - return nf_ct_net(exp->master); + return read_pnet(&exp->net); +} + +static inline bool nf_ct_exp_zone_equal_any(const struct nf_conntrack_expect *a, + const struct nf_conntrack_zone *b) +{ +#ifdef CONFIG_NF_CONNTRACK_ZONES + return a->zone.id == b->id; +#else + return true; +#endif } #define NF_CT_EXP_POLICY_NAME_LEN 16 diff --git a/net/netfilter/nf_conntrack_broadcast.c b/net/netfilter/nf_conntrack_broadcast.c index 721b3e87416b..d44d9379a8a0 100644 --- a/net/netfilter/nf_conntrack_broadcast.c +++ b/net/netfilter/nf_conntrack_broadcast.c @@ -21,6 +21,7 @@ int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int timeout) { const struct nf_conntrack_helper *helper; + struct net *net = read_pnet(&ct->ct_net); struct nf_conntrack_expect *exp; struct iphdr *iph = ip_hdr(skb); struct rtable *rt = skb_rtable(skb); @@ -71,7 +72,10 @@ int nf_conntrack_broadcast_help(struct sk_buff *skb, exp->flags = NF_CT_EXPECT_PERMANENT; exp->class = NF_CT_EXPECT_CLASS_DEFAULT; rcu_assign_pointer(exp->helper, helper); - + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif nf_ct_expect_related(exp, 0); nf_ct_expect_put(exp); diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index c47f7eacf78a..379711ea5ab6 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -113,8 +113,8 @@ nf_ct_exp_equal(const struct nf_conntrack_tuple *tuple, const struct net *net) { return nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) && - net_eq(net, nf_ct_net(i->master)) && - nf_ct_zone_equal_any(i->master, zone); + net_eq(net, read_pnet(&i->net)) && + nf_ct_exp_zone_equal_any(i, zone); } bool nf_ct_remove_expect(struct nf_conntrack_expect *exp) @@ -326,6 +326,7 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class, { struct nf_conntrack_helper *helper = NULL; struct nf_conn *ct = exp->master; + struct net *net = read_pnet(&ct->ct_net); struct nf_conn_help *help; int len; @@ -343,6 +344,10 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class, helper = rcu_dereference(help->helper); rcu_assign_pointer(exp->helper, helper); + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif exp->tuple.src.l3num = family; exp->tuple.dst.protonum = proto; diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 90c32031bcf1..b1b824f372da 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3520,6 +3520,7 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, struct nf_conntrack_tuple *tuple, struct nf_conntrack_tuple *mask) { + struct net *net = read_pnet(&ct->ct_net); struct nf_conntrack_expect *exp; struct nf_conn_help *help; u32 class = 0; @@ -3559,6 +3560,10 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, exp->class = class; exp->master = ct; + write_pnet(&exp->net, net); +#ifdef CONFIG_NF_CONNTRACK_ZONES + exp->zone = ct->zone; +#endif if (!helper) helper = rcu_dereference(help->helper); rcu_assign_pointer(exp->helper, helper); -- 2.43.0