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authorXiyu Yang <xiyuyang19@fudan.edu.cn>2021-09-09 06:32:00 +0200
committerDavid S. Miller <davem@davemloft.net>2021-09-09 12:00:20 +0200
commit9b6ff7eb666415e1558f1ba8a742f5db6a9954de (patch)
tree2961aada1fd30146e1b32903e13fa377e67069fe /net/l2tp
parentnet/af_unix: fix a data-race in unix_dgram_poll (diff)
downloadlinux-9b6ff7eb666415e1558f1ba8a742f5db6a9954de.tar.xz
linux-9b6ff7eb666415e1558f1ba8a742f5db6a9954de.zip
net/l2tp: Fix reference count leak in l2tp_udp_recv_core
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>
Diffstat (limited to 'net/l2tp')
-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 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);