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authorXiyu Yang <xiyuyang19@fudan.edu.cn>2021-09-09 12:32:00 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-22 11:41:27 +0200
commitccc0addcdc6c2e6753b7535055e625714706a8ea (patch)
tree0bbf55b4901f41ae18e1c8030ca8caee90ec9c59
parent1969452d411a73a3125c326c6db0c8433f31dfd5 (diff)
net/l2tp: Fix reference count leak in l2tp_udp_recv_core
commit 9b6ff7eb666415e1558f1ba8a742f5db6a9954de upstream. The reference count leak issue may take place in an error handling path. If both conditions of tunnel->version == L2TP_HDR_VER_3 and the return value of l2tp_v3_ensure_opt_in_linear is nonzero, the function would directly jump to label invalid, without decrementing the reference count of the l2tp_session object session increased earlier by l2tp_tunnel_get_session(). This may result in refcount leaks. Fix this issue by decrease the reference count before jumping to the label invalid. Fixes: 4522a70db7aa ("l2tp: fix reading optional fields of L2TPv3") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/l2tp/l2tp_core.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 653892ea8f14..9a85b0133991 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -990,8 +990,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
}
if (tunnel->version == L2TP_HDR_VER_3 &&
- l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+ l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) {
+ l2tp_session_dec_refcount(session);
goto error;
+ }
l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook);
l2tp_session_dec_refcount(session);