path: root/net/netlink/genetlink.c
diff options
authorMatti Vaittinen <>2016-01-11 14:26:19 +0200
committerDavid S. Miller <>2016-01-12 16:40:15 -0500
commitccdf6ce6a8dba374668ae9b4d763e19903611c38 (patch)
tree80e82e6d7ecc3d5204bcb83478dd36beadc06451 /net/netlink/genetlink.c
parent06928b3870d213cb42b00e2949419f2d44b9d45f (diff)
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 <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net/netlink/genetlink.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index bc0e504f33a6..a992083c0a64 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -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 +
size_t nlen = new_longs * sizeof(unsigned long);