From: Li RongQing <lirongqing@baidu.com>
Date: Fri, 10 Jan 2020 09:04:37 +0800
Subject: bpf: Return -EBADRQC for invalid map type in __bpf_tx_xdp_map
Patch-mainline: v5.6-rc1
Git-commit: 0a29275b6300f39f78a87f2038bbfe5bdbaeca47
References: bsc#1177028

A negative value should be returned if map->map_type is invalid
although that is impossible now, but if we run into such situation
in future, then xdpbuff could be leaked.

Daniel Borkmann suggested:

-EBADRQC should be returned to stay consistent with generic XDP
for the tracepoint output and not to be confused with -EOPNOTSUPP
from other locations like dev_map_enqueue() when ndo_xdp_xmit is
missing and such.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1578618277-18085-1-git-send-email-lirongqing@baidu.com
Acked-by: Gary Lin <glin@suse.com>
---
 net/core/filter.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3523,7 +3523,7 @@ static int __bpf_tx_xdp_map(struct net_d
 	case BPF_MAP_TYPE_XSKMAP:
 		return __xsk_map_redirect(fwd, xdp);
 	default:
-		break;
+		return -EBADRQC;
 	}
 	return 0;
 }