[PATCH AUTOSEL 5.4 307/459] bpf: Return -EBADRQC for invalid map type in __bpf_tx_xdp_map

[Sasha Levin]

From: Li RongQing <lirongqing@xxxxxxxxx>

[ Upstream commit 0a29275b6300f39f78a87f2038bbfe5bdbaeca47 ]

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@xxxxxxxxxxxxx>
Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/1578618277-18085-1-git-send-email-lirongqing@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/core/filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 1a78d64096bbd..d59dbc88fef5d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3543,7 +3543,7 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
 		return err;
 	}
 	default:
-		break;
+		return -EBADRQC;
 	}
 	return 0;
 }
-- 
2.20.1