diff mbox series

[ipsec] af_key: Reject optional tunnel/BEET mode templates in outbound policies

Message ID 636514c1-3d97-46eb-48e2-6f8b7c02464a@strongswan.org (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series [ipsec] af_key: Reject optional tunnel/BEET mode templates in outbound policies | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 3 maintainers not CCed: kuba@kernel.org edumazet@google.com pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch fail ERROR: do not use assignment in if condition
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Tobias Brunner May 9, 2023, 9 a.m. UTC
xfrm_state_find() uses `encap_family` of the current template with
the passed local and remote addresses to find a matching state.
If an optional tunnel or BEET mode template is skipped in a mixed-family
scenario, there could be a mismatch causing an out-of-bounds read as
the addresses were not replaced to match the family of the next template.

While there are theoretical use cases for optional templates in outbound
policies, the only practical one is to skip IPComp states in inbound
policies if uncompressed packets are received that are handled by an
implicitly created IPIP state instead.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Tobias Brunner <tobias@strongswan.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 net/key/af_key.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Steffen Klassert May 11, 2023, 10:04 a.m. UTC | #1
On Tue, May 09, 2023 at 11:00:06AM +0200, Tobias Brunner wrote:
> xfrm_state_find() uses `encap_family` of the current template with
> the passed local and remote addresses to find a matching state.
> If an optional tunnel or BEET mode template is skipped in a mixed-family
> scenario, there could be a mismatch causing an out-of-bounds read as
> the addresses were not replaced to match the family of the next template.
> 
> While there are theoretical use cases for optional templates in outbound
> policies, the only practical one is to skip IPComp states in inbound
> policies if uncompressed packets are received that are handled by an
> implicitly created IPIP state instead.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Tobias Brunner <tobias@strongswan.org>
> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Also applied, thanks a lot!
diff mbox series

Patch

diff --git a/net/key/af_key.c b/net/key/af_key.c
index a815f5ab4c49..31ab12fd720a 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1940,7 +1940,8 @@  static u32 gen_reqid(struct net *net)
 }
 
 static int
-parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_ipsecrequest *rq)
+parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_policy *pol,
+		   struct sadb_x_ipsecrequest *rq)
 {
 	struct net *net = xp_net(xp);
 	struct xfrm_tmpl *t = xp->xfrm_vec + xp->xfrm_nr;
@@ -1958,9 +1959,12 @@  parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_ipsecrequest *rq)
 	if ((mode = pfkey_mode_to_xfrm(rq->sadb_x_ipsecrequest_mode)) < 0)
 		return -EINVAL;
 	t->mode = mode;
-	if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_USE)
+	if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_USE) {
+		if ((mode == XFRM_MODE_TUNNEL || mode == XFRM_MODE_BEET) &&
+		    pol->sadb_x_policy_dir == IPSEC_DIR_OUTBOUND)
+			return -EINVAL;
 		t->optional = 1;
-	else if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_UNIQUE) {
+	} else if (rq->sadb_x_ipsecrequest_level == IPSEC_LEVEL_UNIQUE) {
 		t->reqid = rq->sadb_x_ipsecrequest_reqid;
 		if (t->reqid > IPSEC_MANUAL_REQID_MAX)
 			t->reqid = 0;
@@ -2002,7 +2006,7 @@  parse_ipsecrequests(struct xfrm_policy *xp, struct sadb_x_policy *pol)
 		    rq->sadb_x_ipsecrequest_len < sizeof(*rq))
 			return -EINVAL;
 
-		if ((err = parse_ipsecrequest(xp, rq)) < 0)
+		if ((err = parse_ipsecrequest(xp, pol, rq)) < 0)
 			return err;
 		len -= rq->sadb_x_ipsecrequest_len;
 		rq = (void*)((u8*)rq + rq->sadb_x_ipsecrequest_len);