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author | Nikolay Aleksandrov <nikolay@nvidia.com> | 2021-12-27 19:21:15 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-05 12:42:36 +0100 |
commit | a22ac8009f7e747e2bc1c76679bf1505718e2400 (patch) | |
tree | 9aecbf92a8b7127b7cca1f31c226424bd724041a /net/bridge | |
parent | a780f0dd250776234bcb5ff67ed4a8e7e3d1d89c (diff) | |
download | linux-stable-a22ac8009f7e747e2bc1c76679bf1505718e2400.tar.gz linux-stable-a22ac8009f7e747e2bc1c76679bf1505718e2400.tar.bz2 linux-stable-a22ac8009f7e747e2bc1c76679bf1505718e2400.zip |
net: bridge: mcast: add and enforce query interval minimum
[ Upstream commit 99b40610956a8a8755653a67392e2a8b772453be ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/bridge')
-rw-r--r-- | net/bridge/br_multicast.c | 16 | ||||
-rw-r--r-- | net/bridge/br_netlink.c | 2 | ||||
-rw-r--r-- | net/bridge/br_private.h | 3 | ||||
-rw-r--r-- | net/bridge/br_sysfs_br.c | 2 | ||||
-rw-r--r-- | net/bridge/br_vlan_options.c | 2 |
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 5c6c4305ed23..09812df3bc91 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 fd5e7e74573c..30c9411bfb64 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 @@ -968,6 +969,8 @@ 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]) { |