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| author | Nikolay Aleksandrov <nikolay@nvidia.com> | 2021-12-27 18:21:15 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-12-29 21:59:37 +0100 |
| commit | 99b40610956a8a8755653a67392e2a8b772453be (patch) | |
| tree | 53c62e4e8b7202de4f28fc10af540f87de143ce1 /net/bridge/br_multicast.c | |
| parent | ipv6: raw: check passed optlen before reading (diff) | |
| download | linux-99b40610956a8a8755653a67392e2a8b772453be.tar.xz linux-99b40610956a8a8755653a67392e2a8b772453be.zip | |
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>
Diffstat (limited to 'net/bridge/br_multicast.c')
| -rw-r--r-- | net/bridge/br_multicast.c | 16 |
1 files changed, 16 insertions, 0 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 |