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authorGuillaume Nault <g.nault@alphalink.fr>2017-04-03 12:03:13 +0200
committerDavid S. Miller <davem@davemloft.net>2017-04-04 10:00:56 -0700
commite08293a4ccbcc993ded0fdc46f1e57926b833d63 (patch)
tree4caf25fa597dd173c836735c61724499983a9d93 /net/l2tp/l2tp_netlink.c
parenttcp: minimize false-positives on TCP/GRO check (diff)
downloadlinux-dev-e08293a4ccbcc993ded0fdc46f1e57926b833d63.tar.xz
linux-dev-e08293a4ccbcc993ded0fdc46f1e57926b833d63.zip
l2tp: take reference on sessions being dumped
Take a reference on the sessions returned by l2tp_session_find_nth() (and rename it l2tp_session_get_nth() to reflect this change), so that caller is assured that the session isn't going to disappear while processing it. For procfs and debugfs handlers, the session is held in the .start() callback and dropped in .show(). Given that pppol2tp_seq_session_show() dereferences the associated PPPoL2TP socket and that l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to call the session's .ref() callback to prevent the socket from going away from under us. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp/l2tp_netlink.c')
-rw-r--r--net/l2tp/l2tp_netlink.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 93e317377c66..7e3e669baac4 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -867,7 +867,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
goto out;
}
- session = l2tp_session_find_nth(tunnel, si);
+ session = l2tp_session_get_nth(tunnel, si, false);
if (session == NULL) {
ti++;
tunnel = NULL;
@@ -877,8 +877,11 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
- session, L2TP_CMD_SESSION_GET) < 0)
+ session, L2TP_CMD_SESSION_GET) < 0) {
+ l2tp_session_dec_refcount(session);
break;
+ }
+ l2tp_session_dec_refcount(session);
si++;
}