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| author | Xiyu Yang <xiyuyang19@fudan.edu.cn> | 2021-09-09 07:32:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 13:27:56 +0300 |
| commit | edfab735d5182fbfe5b5773869304291aaa12be8 (patch) | |
| tree | e4c51d9a5ddcf31bd00b725cbe25ac393dc07a57 /net/l2tp/l2tp_core.c | |
| parent | 6c3cb65d561e76fd0398026c023e587fec70e188 (diff) | |
| download | linux-edfab735d5182fbfe5b5773869304291aaa12be8.tar.xz | |
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>
Diffstat (limited to 'net/l2tp/l2tp_core.c')
| -rw-r--r-- | net/l2tp/l2tp_core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 203890e378cb..561b6d67ab8b 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); |