ethtool: Fix potential user buffer overflow for ETHTOOL_{G, S}RXFH
struct ethtool_rxnfc was originally defined in 2.6.27 for the
ETHTOOL_{G,S}RXFH command with only the cmd, flow_type and data
fields. It was then extended in 2.6.30 to support various additional
commands. These commands should have been defined to use a new
structure, but it is too late to change that now.
Since user-space may still be using the old structure definition
for the ETHTOOL_{G,S}RXFH commands, and since they do not need the
additional fields, only copy the originally defined fields to and
from user-space.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 276b40a..b4207ca 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -379,6 +379,8 @@
__u32 flow_type;
/* The rx flow hash value or the rule DB size */
__u64 data;
+ /* The following fields are not valid and must not be used for
+ * the ETHTOOL_{G,X}RXFH commands. */
struct ethtool_rx_flow_spec fs;
__u32 rule_cnt;
__u32 rule_locs[0];