summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNikolay Aleksandrov <nikolay@nvidia.com>2021-12-27 19:21:15 +0200
committerJakub Kicinski <kuba@kernel.org>2021-12-29 12:59:37 -0800
commit99b40610956a8a8755653a67392e2a8b772453be (patch)
tree53c62e4e8b7202de4f28fc10af540f87de143ce1
parentfb7bc9204095090731430c8921f9e629740c110a (diff)
net: bridge: mcast: add and enforce query interval minimum
As reported[1] if query interval is set too low and we have multiple bridges or even a single bridge with multiple querier vlans configured we can crash the machine. Add a 1 second minimum which must be enforced by overwriting the value if set lower (i.e. without returning an error) to avoid breaking user-space. If that happens a log message is emitted to let the administrator know that the interval has been set to the minimum. The issue has been present since these intervals could be user-controlled. [1] https://lore.kernel.org/netdev/e8b9ce41-57b9-b6e2-a46a-ff9c791cf0ba@gmail.com/ Fixes: d902eee43f19 ("bridge: Add multicast count/interval sysfs entries") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/bridge/br_multicast.c16
-rw-r--r--net/bridge/br_netlink.c2
-rw-r--r--net/bridge/br_private.h3
-rw-r--r--net/bridge/br_sysfs_br.c2
-rw-r--r--net/bridge/br_vlan_options.c2
5 files changed, 22 insertions, 3 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index f3d751105343..998da4a2d209 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -4522,6 +4522,22 @@ int br_multicast_set_mld_version(struct net_bridge_mcast *brmctx,
}
#endif
+void br_multicast_set_query_intvl(struct net_bridge_mcast *brmctx,
+ unsigned long val)
+{
+ unsigned long intvl_jiffies = clock_t_to_jiffies(val);
+
+ if (intvl_jiffies < BR_MULTICAST_QUERY_INTVL_MIN) {
+ br_info(brmctx->br,
+ "trying to set multicast query interval below minimum, setting to %lu (%ums)\n",
+ jiffies_to_clock_t(BR_MULTICAST_QUERY_INTVL_MIN),
+ jiffies_to_msecs(BR_MULTICAST_QUERY_INTVL_MIN));
+ intvl_jiffies = BR_MULTICAST_QUERY_INTVL_MIN;
+ }
+
+ brmctx->multicast_query_interval = intvl_jiffies;
+}
+
/**
* br_multicast_list_adjacent - Returns snooped multicast addresses
* @dev: The bridge port adjacent to which to retrieve addresses
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 0c8b5f1a15bc..701dd8b8455e 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1357,7 +1357,7 @@ static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
if (data[IFLA_BR_MCAST_QUERY_INTVL]) {
u64 val = nla_get_u64(data[IFLA_BR_MCAST_QUERY_INTVL]);
- br->multicast_ctx.multicast_query_interval = clock_t_to_jiffies(val);
+ br_multicast_set_query_intvl(&br->multicast_ctx, val);
}
if (data[IFLA_BR_MCAST_QUERY_RESPONSE_INTVL]) {
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index c0efd697865a..4ed7f11042e8 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -28,6 +28,7 @@
#define BR_MAX_PORTS (1<<BR_PORT_BITS)
#define BR_MULTICAST_DEFAULT_HASH_MAX 4096
+#define BR_MULTICAST_QUERY_INTVL_MIN msecs_to_jiffies(1000)
#define BR_HWDOM_MAX BITS_PER_LONG
@@ -963,6 +964,8 @@ int br_multicast_dump_querier_state(struct sk_buff *skb,
int nest_attr);
size_t br_multicast_querier_state_size(void);
size_t br_rports_size(const struct net_bridge_mcast *brmctx);
+void br_multicast_set_query_intvl(struct net_bridge_mcast *brmctx,
+ unsigned long val);
static inline bool br_group_is_l2(const struct br_ip *group)
{
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index d9a89ddd0331..f5bd1114a434 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -658,7 +658,7 @@ static ssize_t multicast_query_interval_show(struct device *d,
static int set_query_interval(struct net_bridge *br, unsigned long val,
struct netlink_ext_ack *extack)
{
- br->multicast_ctx.multicast_query_interval = clock_t_to_jiffies(val);
+ br_multicast_set_query_intvl(&br->multicast_ctx, val);
return 0;
}
diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index 8ffd4ed2563c..bf1ac0874279 100644
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -521,7 +521,7 @@ static int br_vlan_process_global_one_opts(const struct net_bridge *br,
u64 val;
val = nla_get_u64(tb[BRIDGE_VLANDB_GOPTS_MCAST_QUERY_INTVL]);
- v->br_mcast_ctx.multicast_query_interval = clock_t_to_jiffies(val);
+ br_multicast_set_query_intvl(&v->br_mcast_ctx, val);
*changed = true;
}
if (tb[BRIDGE_VLANDB_GOPTS_MCAST_QUERY_RESPONSE_INTVL]) {