From: David Ahern <dsahern@xxxxxxxxx>
commit 0b5e2e39739e861fa5fc84ab27a35dbe62a15330 upstream.
I got too fancy consolidating checks on multipath type. The result
is that path lookups can access 2 different nh_grp structs as exposed
by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to
avoid multiple, nh_grp dereferences and make decisions based on the
consistent struct.
Only 2 places left using nexthop_is_multipath are within IPv6, both
only check that the nexthop is a multipath for a branching decision
which are acceptable.
Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Acked-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/nexthop.h | 41 +++++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 16 deletions(-)
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -137,21 +137,20 @@ static inline unsigned int nexthop_num_p
{
unsigned int rc = 1;
- if (nexthop_is_multipath(nh)) {
+ if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
- rc = nh_grp->num_nh;
+ if (nh_grp->mpath)
+ rc = nh_grp->num_nh;
}
return rc;
}
static inline
-struct nexthop *nexthop_mpath_select(const struct nexthop *nh, int nhsel)
+struct nexthop *nexthop_mpath_select(const struct nh_group *nhg, int nhsel)
{
- const struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
-
/* for_nexthops macros in fib_semantics.c grabs a pointer to
* the nexthop before checking nhsel
*/
@@ -186,12 +185,14 @@ static inline bool nexthop_is_blackhole(
{
const struct nh_info *nhi;
- if (nexthop_is_multipath(nh)) {
- if (nexthop_num_path(nh) > 1)
- return false;
- nh = nexthop_mpath_select(nh, 0);
- if (!nh)
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ if (nh_grp->num_nh > 1)
return false;
+
+ nh = nh_grp->nh_entries[0].nh;
}
nhi = rcu_dereference_rtnl(nh->nh_info);
@@ -217,10 +218,15 @@ struct fib_nh_common *nexthop_fib_nhc(st
BUILD_BUG_ON(offsetof(struct fib_nh, nh_common) != 0);
BUILD_BUG_ON(offsetof(struct fib6_nh, nh_common) != 0);
- if (nexthop_is_multipath(nh)) {
- nh = nexthop_mpath_select(nh, nhsel);
- if (!nh)
- return NULL;
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ if (nh_grp->mpath) {
+ nh = nexthop_mpath_select(nh_grp, nhsel);
+ if (!nh)
+ return NULL;
+ }
}
nhi = rcu_dereference_rtnl(nh->nh_info);
@@ -264,8 +270,11 @@ static inline struct fib6_nh *nexthop_fi
{
struct nh_info *nhi;
- if (nexthop_is_multipath(nh)) {
- nh = nexthop_mpath_select(nh, 0);
+ if (nh->is_group) {
+ struct nh_group *nh_grp;
+
+ nh_grp = rcu_dereference_rtnl(nh->nh_grp);
+ nh = nexthop_mpath_select(nh_grp, 0);
if (!nh)
return NULL;
}
