net: clear heap allocation for ETHTOOL_GRXCLSRLALL

commit ae6df5f96a51818d6376da5307d773baeece4014 upstream.

Calling ETHTOOL_GRXCLSRLALL with a large rule_cnt will allocate kernel
heap without clearing it. For the one driver (niu) that implements it,
it will leave the unused portion of heap unchanged and copy the full
contents back to userspace.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 450862e980c8ac080598d045cebbf0c15af3989a..abbe8fa66a51baff4bb51c35966491351837639f 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -265,7 +265,7 @@ static int ethtool_get_rxnfc(struct net_device *dev,
        if (info.cmd == ETHTOOL_GRXCLSRLALL) {
                if (info.rule_cnt > 0) {
                        if (info.rule_cnt <= KMALLOC_MAX_SIZE / sizeof(u32))
-                               rule_buf = kmalloc(info.rule_cnt * sizeof(u32),
+                               rule_buf = kzalloc(info.rule_cnt * sizeof(u32),
                                                   GFP_USER);
                        if (!rule_buf)
                                return -ENOMEM;