ethtool: Update ethtool_rxnfc::rule_cnt on return from ETHTOOL_GRXCLSRLALL
A user-space process must use ETHTOOL_GRXCLSRLCNT to find the number
of classification rules, then allocate a buffer of the right size,
then use ETHTOOL_GRXCLSRLALL to fill the buffer. If some other
process inserts or deletes a rule between those two operations,
the user buffer might turn out to be the wrong size.
If it's too small, the return value will be -EMSGSIZE. But if it's
too large, there is no indication of this. Fix this by updating
the rule_cnt field on return.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
index 4223830..f30b96f 100644
--- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
+++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
@@ -1676,6 +1676,7 @@
}
cmd->data = MAX_FILER_IDX;
+ cmd->rule_cnt = i;
return 0;
}