2022-03-30 03:12:27

by Wang Hai

Subject: [PATCH net] wireguard: socket: fix memory leak in send6()

I got a memory leak report:

unreferenced object 0xffff8881191fc040 (size 232):
comm "kworker/u17:0", pid 23193, jiffies 4295238848 (age 3464.870s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814c3ef4>] slab_post_alloc_hook+0x84/0x3b0
[<ffffffff814c8977>] kmem_cache_alloc_node+0x167/0x340
[<ffffffff832974fb>] __alloc_skb+0x1db/0x200
[<ffffffff82612b5d>] wg_socket_send_buffer_to_peer+0x3d/0xc0
[<ffffffff8260e94a>] wg_packet_send_handshake_initiation+0xfa/0x110
[<ffffffff8260ec81>] wg_packet_handshake_send_worker+0x21/0x30
[<ffffffff8119c558>] process_one_work+0x2e8/0x770
[<ffffffff8119ca2a>] worker_thread+0x4a/0x4b0
[<ffffffff811a88e0>] kthread+0x120/0x160
[<ffffffff8100242f>] ret_from_fork+0x1f/0x30

In function wg_socket_send_buffer_as_reply_to_skb() or
wg_socket_send_buffer_to_peer(), the semantics of send6()
is required to free skb. But when CONFIG_IPV6 is disable,
kfree_skb() is missing. This patch adds it to fix this bug.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Signed-off-by: Wang Hai <[email protected]>
---
drivers/net/wireguard/socket.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireguard/socket.c b/drivers/net/wireguard/socket.c
index 6f07b949cb81..467eef0e563b 100644
--- a/drivers/net/wireguard/socket.c
+++ b/drivers/net/wireguard/socket.c
@@ -160,6 +160,7 @@ static int send6(struct wg_device *wg, struct sk_buff *skb,
rcu_read_unlock_bh();
return ret;
#else
+ kfree_skb(skb);
return -EAFNOSUPPORT;
#endif
}
--
2.25.1

2022-03-30 12:20:30

by Jason A. Donenfeld

Subject: Re: [PATCH net] wireguard: socket: fix memory leak in send6()

Applied, thanks for the patch.