From 79dc4386aec655ad829f320ab90888bacbc7037b Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 24 Jul 2007 15:32:46 -0700 Subject: [PATCH] [GENETLINK]: Fix race in genl_unregister_mc_groups() family->mcast_groups is protected by genl_lock so it must be held while accessing the list in genl_unregister_mc_groups(). Requires adding a non-locking variant of genl_unregister_mc_group(). Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- net/netlink/genetlink.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index e146531faf1..61d65569e2b 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -200,6 +200,18 @@ int genl_register_mc_group(struct genl_family *family, } EXPORT_SYMBOL(genl_register_mc_group); +static void __genl_unregister_mc_group(struct genl_family *family, + struct genl_multicast_group *grp) +{ + BUG_ON(grp->family != family); + netlink_clear_multicast_users(genl_sock, grp->id); + clear_bit(grp->id, mc_groups); + list_del(&grp->list); + genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); + grp->id = 0; + grp->family = NULL; +} + /** * genl_unregister_mc_group - unregister a multicast group * @@ -217,14 +229,8 @@ EXPORT_SYMBOL(genl_register_mc_group); void genl_unregister_mc_group(struct genl_family *family, struct genl_multicast_group *grp) { - BUG_ON(grp->family != family); genl_lock(); - netlink_clear_multicast_users(genl_sock, grp->id); - clear_bit(grp->id, mc_groups); - list_del(&grp->list); - genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); - grp->id = 0; - grp->family = NULL; + __genl_unregister_mc_group(family, grp); genl_unlock(); } @@ -232,8 +238,10 @@ static void genl_unregister_mc_groups(struct genl_family *family) { struct genl_multicast_group *grp, *tmp; + genl_lock(); list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list) - genl_unregister_mc_group(family, grp); + __genl_unregister_mc_group(family, grp); + genl_unlock(); } /** -- 2.20.1