diff options
| author | Guillaume Nault <g.nault@alphalink.fr> | 2017-03-31 13:02:26 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-04-02 05:16:41 +0200 |
| commit | 57377d63547861919ee634b845c7caa38de4a452 (patch) | |
| tree | 5e00b7be9f0d3abc3b0901662867aba202835c0a /net | |
| parent | l2tp: fix race in l2tp_recv_common() (diff) | |
| download | linux-57377d63547861919ee634b845c7caa38de4a452.tar.xz linux-57377d63547861919ee634b845c7caa38de4a452.zip | |
l2tp: ensure session can't get removed during pppol2tp_session_ioctl()
Holding a reference on session is required before calling
pppol2tp_session_ioctl(). The session could get freed while processing the
ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket,
we also need to take a reference on it in l2tp_session_get().
Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 123b6a2411a0..827e55c41ba2 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1141,11 +1141,18 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, if (stats.session_id != 0) { /* resend to session ioctl handler */ struct l2tp_session *session = - l2tp_session_find(sock_net(sk), tunnel, stats.session_id); - if (session != NULL) - err = pppol2tp_session_ioctl(session, cmd, arg); - else + l2tp_session_get(sock_net(sk), tunnel, + stats.session_id, true); + + if (session) { + err = pppol2tp_session_ioctl(session, cmd, + arg); + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + } else { err = -EBADR; + } break; } #ifdef CONFIG_XFRM |