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authorTobias Brunner <tobias@strongswan.org>2023-05-09 10:59:58 +0200
committerSteffen Klassert <steffen.klassert@secunet.com>2023-05-10 07:04:50 +0200
commit3d776e31c841ba2f69895d2255a49320bec7cea6 (patch)
tree419eee72a9f03edc83953ead50e22e9a0066bfdb /net
parent5fc46f94219d1d103ffb5f0832be9da674d85a73 (diff)
xfrm: Reject optional tunnel/BEET mode templates in outbound policies
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> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net')
-rw-r--r--net/xfrm/xfrm_user.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index af8fbcbfbe69..6794b9dea27a 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1768,7 +1768,7 @@ static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
}
static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family,
- struct netlink_ext_ack *extack)
+ int dir, struct netlink_ext_ack *extack)
{
u16 prev_family;
int i;
@@ -1794,6 +1794,10 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family,
switch (ut[i].mode) {
case XFRM_MODE_TUNNEL:
case XFRM_MODE_BEET:
+ if (ut[i].optional && dir == XFRM_POLICY_OUT) {
+ NL_SET_ERR_MSG(extack, "Mode in optional template not allowed in outbound policy");
+ return -EINVAL;
+ }
break;
default:
if (ut[i].family != prev_family) {
@@ -1831,7 +1835,7 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family,
}
static int copy_from_user_tmpl(struct xfrm_policy *pol, struct nlattr **attrs,
- struct netlink_ext_ack *extack)
+ int dir, struct netlink_ext_ack *extack)
{
struct nlattr *rt = attrs[XFRMA_TMPL];
@@ -1842,7 +1846,7 @@ static int copy_from_user_tmpl(struct xfrm_policy *pol, struct nlattr **attrs,
int nr = nla_len(rt) / sizeof(*utmpl);
int err;
- err = validate_tmpl(nr, utmpl, pol->family, extack);
+ err = validate_tmpl(nr, utmpl, pol->family, dir, extack);
if (err)
return err;
@@ -1919,7 +1923,7 @@ static struct xfrm_policy *xfrm_policy_construct(struct net *net,
if (err)
goto error;
- if (!(err = copy_from_user_tmpl(xp, attrs, extack)))
+ if (!(err = copy_from_user_tmpl(xp, attrs, p->dir, extack)))
err = copy_from_user_sec_ctx(xp, attrs);
if (err)
goto error;
@@ -3498,7 +3502,7 @@ static struct xfrm_policy *xfrm_compile_policy(struct sock *sk, int opt,
return NULL;
nr = ((len - sizeof(*p)) / sizeof(*ut));
- if (validate_tmpl(nr, ut, p->sel.family, NULL))
+ if (validate_tmpl(nr, ut, p->sel.family, p->dir, NULL))
return NULL;
if (p->dir > XFRM_POLICY_OUT)