Subject: [PATCH AUTOSEL 5.5 352/542] bpf: Return -EBADRQC for invalid map type in __bpf_tx_xdp_map

From: Sasha Levin <[email-masked]>
Date: Fri, 14 Feb 2020 10:45:44 -0500

From: Li RongQing <[email-masked]>

[ 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 <[email-masked]>
Signed-off-by: Li RongQing <[email-masked]>
Signed-off-by: Daniel Borkmann <[email-masked]>
Link: https://lore.kernel.org/bpf/[email-masked]
Signed-off-by: Sasha Levin <[email-masked]>
---
 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 538f6a735a19f..f797b1599c92f 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