Commit ccdf6ce6 authored Jan 11, 2016 by Matti Vaittinen Committed by David S. Miller Jan 12, 2016

net: netlink: Fix multicast group storage allocation for families with more than one groups



Multicast groups are stored in global buffer. Check for needed buffer size
incorrectly compares buffer size to first id for family. This means that
for families with more than one mcast id one may allocate too small buffer
and end up writing rest of the groups to some unallocated memory. Fix the
buffer size check to compare allocated space to last mcast id for the
family.

Tested on ARM using kernel 3.14

Signed-off-by: Matti Vaittinen <matti.vaittinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 06928b38

net/netlink/genetlink.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -185,7 +185,7 @@ static int genl_allocate_reserve_groups(int n_groups, int *first_id)
		}
		}

		if (id >= mc_groups_longs * BITS_PER_LONG) {
		if (id + n_groups >= mc_groups_longs * BITS_PER_LONG) {
		unsigned long new_longs = mc_groups_longs +
		BITS_TO_LONGS(n_groups);
		size_t nlen = new_longs * sizeof(unsigned long);