[PATCH 4.18 044/135] net-ethtool: ETHTOOL_GUFO did not and should not require CAP_NET_ADMIN

Greg Kroah-Hartman
2018-10-16T17:13:58Z

From: "Maciej Żenczykowski" <maze@google.com>

[ Upstream commit 474ff2600889e16280dbc6ada8bfecb216169a70 ]

So it should not fail with EPERM even though it is no longer implemented...

This is a fix for:
(userns)$ egrep ^Cap /proc/self/status
CapInh: 0000003fffffffff
CapPrm: 0000003fffffffff
CapEff: 0000003fffffffff
CapBnd: 0000003fffffffff
CapAmb: 0000003fffffffff

(userns)$ tcpdump -i usb_rndis0
tcpdump: WARNING: usb_rndis0: SIOCETHTOOL(ETHTOOL_GUFO) ioctl failed: Operation not permitted
Warning: Kernel filter failed: Bad file descriptor
tcpdump: can't remove kernel filter: Bad file descriptor

With this change it returns EOPNOTSUPP instead of EPERM.

See also https://github.com/the-tcpdump-group/libpcap/issues/689

Fixes: 08a00fea6de2 "net: Remove references to NETIF_F_UFO from ethtool."
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/ethtool.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -2623,6 +2623,7 @@ int dev_ethtool(struct net *net, struct
case ETHTOOL_GPHYSTATS:
case ETHTOOL_GTSO:
case ETHTOOL_GPERMADDR:
+ case ETHTOOL_GUFO:
case ETHTOOL_GGSO:
case ETHTOOL_GGRO:
case ETHTOOL_GFLAGS: