diff mbox series

[29/29] l2tp: WARN_ON rather than BUG_ON in l2tp_session_free

Message ID 20200721173221.4681-30-tparkin@katalix.com
State Changes Requested
Delegated to: David Miller
Headers show
Series l2tp: cleanup checkpatch.pl warnings | expand

Commit Message

Tom Parkin July 21, 2020, 5:32 p.m. UTC 
l2tp_session_free called BUG_ON if the tunnel magic feather value wasn't
correct.  The intent of this was to catch lifetime bugs; for example
early tunnel free due to incorrect use of reference counts.

Since the tunnel magic feather being wrong indicates either early free
or structure corruption, we can avoid doing more damage by simply
leaving the tunnel structure alone.  If the tunnel refcount isn't
dropped when it should be, the tunnel instance will remain in the
kernel, resulting in the tunnel structure and socket leaking.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
---
 net/l2tp/l2tp_core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 34dacb14042f..64c4350b8eb4 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1566,8 +1566,10 @@  void l2tp_session_free(struct l2tp_session *session)
 	struct l2tp_tunnel *tunnel = session->tunnel;
 
 	if (tunnel) {
-		BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
-		l2tp_tunnel_dec_refcount(tunnel);
+		if (tunnel->magic == L2TP_TUNNEL_MAGIC)
+			l2tp_tunnel_dec_refcount(tunnel);
+		else
+			WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
 	}
 
 	kfree(session);