path: root/net/netlink/genetlink.c
diff options
authorStanislaw Gruszka <>2017-03-22 16:08:33 +0100
committerDavid S. Miller <>2017-03-22 15:38:43 -0700
commit1d2a6a5e4bf2921531071fcff8538623dce74efa (patch)
tree45076a17d569a552c96db9f823c2824d7ea4b656 /net/netlink/genetlink.c
parenta97e50cc4cb67e1e7bff56f6b41cda62ca832336 (diff)
genetlink: fix counting regression on ctrl_dumpfamily()
Commit 2ae0f17df1cd ("genetlink: use idr to track families") replaced if (++n < fams_to_skip) continue; into: if (n++ < fams_to_skip) continue; This subtle change cause that on retry ctrl_dumpfamily() call we omit one family that failed to do ctrl_fill_info() on previous call, because cb->args[0] = n number counts also family that failed to do ctrl_fill_info(). Patch fixes the problem and avoid confusion in the future just decrease n counter when ctrl_fill_info() fail. User visible problem caused by this bug is failure to get access to some genetlink family i.e. nl80211. However problem is reproducible only if number of registered genetlink families is big enough to cause second call of ctrl_dumpfamily(). Cc: Xose Vazquez Perez <> Cc: Larry Finger <> Cc: Johannes Berg <> Fixes: 2ae0f17df1cd ("genetlink: use idr to track families") Signed-off-by: Stanislaw Gruszka <> Acked-by: Johannes Berg <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net/netlink/genetlink.c')
1 files changed, 3 insertions, 1 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index fb6e10fdb217..92e0981f7404 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -783,8 +783,10 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ skb, CTRL_CMD_NEWFAMILY) < 0) {
+ n--;
+ }
cb->args[0] = n;