diff options
Diffstat (limited to 'net/netlink/genetlink.c')
| -rw-r--r-- | net/netlink/genetlink.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index c68ce73619b5..353909d46dda 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -65,8 +65,12 @@ static struct list_head family_ht[GENL_FAM_TAB_SIZE]; * To avoid an allocation at boot of just one unsigned long, * declare it global instead. * Bit 0 is marked as already used since group 0 is invalid. + * Bit 1 is marked as already used since the drop-monitor code + * abuses the API and thinks it can statically use group 1. + * That group will typically conflict with other groups that + * any proper users use. */ -static unsigned long mc_group_start = 0x1; +static unsigned long mc_group_start = 0x3; static unsigned long *mc_groups = &mc_group_start; static unsigned long mc_groups_longs = 1; @@ -160,9 +164,11 @@ int genl_register_mc_group(struct genl_family *family, genl_lock_all(); - /* special-case our own group */ + /* special-case our own group and hacks */ if (grp == ¬ify_grp) id = GENL_ID_CTRL; + else if (strcmp(family->name, "NET_DM") == 0) + id = 1; else id = find_first_zero_bit(mc_groups, mc_groups_longs * BITS_PER_LONG); @@ -245,7 +251,8 @@ static void __genl_unregister_mc_group(struct genl_family *family, rcu_read_unlock(); netlink_table_ungrab(); - clear_bit(grp->id, mc_groups); + if (grp->id != 1) + clear_bit(grp->id, mc_groups); list_del(&grp->list); genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); grp->id = 0; |