[PATCH 4.9 05/47] inet_diag: Fix error path to cancel the meseage in inet_req_diag_fill()

[Greg Kroah-Hartman]

From: Wang Hai <wangha...@huawei.com>

[ Upstream commit e33de7c5317e2827b2ba6fd120a505e9eb727b05 ]

nlmsg_cancel() needs to be called in the error path of
inet_req_diag_fill to cancel the message.

Fixes: d545caca827b ("net: inet: diag: expose the socket mark to privileged 
processes.")
Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Wang Hai <wangha...@huawei.com>
Link: https://lore.kernel.org/r/20201116082018.16496-1-wangha...@huawei.com
Signed-off-by: Jakub Kicinski <k...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/ipv4/inet_diag.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -355,8 +355,10 @@ static int inet_req_diag_fill(struct soc
        r->idiag_inode  = 0;
 
        if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
-                                    inet_rsk(reqsk)->ir_mark))
+                                    inet_rsk(reqsk)->ir_mark)) {
+               nlmsg_cancel(skb, nlh);
                return -EMSGSIZE;
+       }
 
        nlmsg_end(skb, nlh);
        return 0;