From: Jiri Pirko <jiri@xxxxxxxxxx> [ Upstream commit 8f1948bdcf2fb50e9092c0950c3c9ac591382101 ] In genl_bind(), currently genl_lock and write cb_lock are taken for iteration of genl_fam_idr and processing of static values stored in struct genl_family. Take just read cb_lock for this task as it is sufficient to guard the idr and the struct against concurrent genl_register/unregister_family() calls. This will allow to run genl command processing in genl_rcv() and mnl_socket_setsockopt(.., NETLINK_ADD_MEMBERSHIP, ..) in parallel. Reported-by: Vikas Gupta <vikas.gupta@xxxxxxxxxxxx> Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220825081940.1283335-1-jiri@xxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/netlink/genetlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 57010927e20a..76aed0571e3a 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1362,7 +1362,7 @@ static int genl_bind(struct net *net, int group) unsigned int id; int ret = 0; - genl_lock_all(); + down_read(&cb_lock); idr_for_each_entry(&genl_fam_idr, family, id) { const struct genl_multicast_group *grp; @@ -1383,7 +1383,7 @@ static int genl_bind(struct net *net, int group) break; } - genl_unlock_all(); + up_read(&cb_lock); return ret; } -- 2.35.1
