[PATCH 5.9 007/252] inet_diag: Fix error path to cancel the meseage in inet_req_diag_fill()

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Wang Hai <wanghai38@xxxxxxxxxx>

[ 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 <hulkci@xxxxxxxxxx>
Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20201116082018.16496-1-wanghai38@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 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
@@ -462,8 +462,10 @@ 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;