iavf: validate pointers

stable inclusion
form stable-v5.10.82
commit 77f5ae5441f0d739c7e1780f309088143252a6ef
bugzilla: 185877 https://gitee.com/openeuler/kernel/issues/I4QU6V

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=77f5ae5441f0d739c7e1780f309088143252a6ef

--------------------------------

[ Upstream commit 131b0edc ]

In some cases, the ethtool get_rxfh handler may be called with a null
key or indir parameter. So check these pointers, or you will have a very
bad day.

Fixes: 43a3d9ba ("i40evf: Allow PF driver to configure RSS")
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NTony Brelinski <tony.brelinski@intel.com>
Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/intel/iavf/iavf_ethtool.c

@@ -991,11 +991,10 @@ static int iavf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
 
 	if (hfunc)
 		*hfunc = ETH_RSS_HASH_TOP;
-	if (!indir)
-		return 0;
-
+	if (key)
 		memcpy(key, adapter->rss_key, adapter->rss_key_size);
 
+	if (indir)
 		/* Each 32 bits pointed by 'indir' is stored with a lut entry */
 		for (i = 0; i < adapter->rss_lut_size; i++)
 			indir[i] = (u32)adapter->rss_lut[i];