From 99b40610956a8a8755653a67392e2a8b772453be Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Mon, 27 Dec 2021 19:21:15 +0200 Subject: 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 Signed-off-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski --- net/bridge/br_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/bridge/br_netlink.c') 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]) { -- cgit v1.2.3