Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] net/l2tp: Fix reference count leak in l2tp_udp_recv_core | Date | Thu, 9 Sep 2021 12:32:00 +0800 |
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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.
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> --- net/l2tp/l2tp_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 53486b162f01..93271a2632b8 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -869,8 +869,10 @@ 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 invalid; + } l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); l2tp_session_dec_refcount(session); -- 2.7.4
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