diff options
| author | Guillaume Nault <g.nault@alphalink.fr> | 2017-09-22 15:39:23 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-13 10:32:50 +0200 |
| commit | 8aeff206767ea83d5b36746e03a4dfc9cec8a6b2 (patch) | |
| tree | bba7533b90987c0f6ffca0a5f09d63d29a6d18c7 /net | |
| parent | a5ad06fc4b7b22f6df0c21b7052a82e039305a14 (diff) | |
l2tp: ensure sessions are freed after their PPPOL2TP socket
commit cdd10c9627496ad25c87ce6394e29752253c69d3 upstream.
If l2tp_tunnel_delete() or l2tp_tunnel_closeall() deletes a session
right after pppol2tp_release() orphaned its socket, then the 'sock'
variable of the pppol2tp_session_close() callback is NULL. Yet the
session is still used by pppol2tp_release().
Therefore we need to take an extra reference in any case, to prevent
l2tp_tunnel_delete() or l2tp_tunnel_closeall() from freeing the session.
Since the pppol2tp_session_close() callback is only set if the session
is associated to a PPPOL2TP socket and that both l2tp_tunnel_delete()
and l2tp_tunnel_closeall() hold the PPPOL2TP socket before calling
pppol2tp_session_close(), we're sure that pppol2tp_session_close() and
pppol2tp_session_destruct() are paired and called in the right order.
So the reference taken by the former will be released by the later.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 16b63e60396f..d919b3e6b548 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -437,11 +437,11 @@ static void pppol2tp_session_close(struct l2tp_session *session) BUG_ON(session->magic != L2TP_SESSION_MAGIC); - if (sock) { + if (sock) inet_shutdown(sock, SEND_SHUTDOWN); - /* Don't let the session go away before our socket does */ - l2tp_session_inc_refcount(session); - } + + /* Don't let the session go away before our socket does */ + l2tp_session_inc_refcount(session); } /* Really kill the session socket. (Called from sock_put() if |