diff options
| author | Florian Westphal <fw@strlen.de> | 2026-03-10 00:28:29 +0100 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2026-03-13 15:31:14 +0100 |
| commit | f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05 (patch) | |
| tree | e1351acf4cc594a03f912f40dd7e0c1c2cb98fc2 /net | |
| parent | 5cb81eeda909dbb2def209dd10636b51549a3f8a (diff) | |
netfilter: conntrack: add missing netlink policy validations
Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.
These attributes are used by the kernel without any validation.
Extend the netlink policies accordingly.
Quoting the reporter:
nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE
value directly to ct->proto.sctp.state without checking that it is
within the valid range. [..]
and: ... with exp->dir = 100, the access at
ct->master->tuplehash[100] reads 5600 bytes past the start of a
320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by
UBSAN.
Fixes: 076a0ca02644 ("netfilter: ctnetlink: add NAT support for expectations")
Fixes: a258860e01b8 ("netfilter: ctnetlink: add full support for SCTP to ctnetlink")
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 2 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_proto_sctp.c | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 65aa44a12d01..c156574e1273 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3489,7 +3489,7 @@ ctnetlink_change_expect(struct nf_conntrack_expect *x, #if IS_ENABLED(CONFIG_NF_NAT) static const struct nla_policy exp_nat_nla_policy[CTA_EXPECT_NAT_MAX+1] = { - [CTA_EXPECT_NAT_DIR] = { .type = NLA_U32 }, + [CTA_EXPECT_NAT_DIR] = NLA_POLICY_MAX(NLA_BE32, IP_CT_DIR_REPLY), [CTA_EXPECT_NAT_TUPLE] = { .type = NLA_NESTED }, }; #endif diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 7c6f7c9f7332..645d2c43ebf7 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -582,7 +582,8 @@ nla_put_failure: } static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = { - [CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 }, + [CTA_PROTOINFO_SCTP_STATE] = NLA_POLICY_MAX(NLA_U8, + SCTP_CONNTRACK_HEARTBEAT_SENT), [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 }, [CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 }, }; |