[PATCH 6.0 0314/1073] wifi: iwlwifi: mei: fix potential NULL-ptr deref after clone

Greg Kroah-Hartman
2022-12-28T15:34:35Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit d3df49dda431f7ae4132a9a0ac25a5134c04e812 ]

If cloning the SKB fails, don't try to use it, but rather return
as if we should pass it.

Coverity CID: 1503456

Fixes: 2da4366f9e2c ("iwlwifi: mei: add the driver to allow cooperation with CSME")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20221030191011.0ce03ba99601.I87960b7cb0a3d16b9fd8d9144027e7e2587f5a58@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/intel/iwlwifi/mei/net.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c
index 3472167c8370..eac46d1a397a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mei/net.c
+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Copyright (C) 2021 Intel Corporation
+ * Copyright (C) 2021-2022 Intel Corporation
*/

#include <uapi/linux/if_ether.h>
@@ -337,10 +337,14 @@ rx_handler_result_t iwl_mei_rx_filter(struct sk_buff *orig_skb,
if (!*pass_to_csme)
return RX_HANDLER_PASS;

- if (ret == RX_HANDLER_PASS)
+ if (ret == RX_HANDLER_PASS) {
skb = skb_copy(orig_skb, GFP_ATOMIC);
- else
+
+ if (!skb)
+ return RX_HANDLER_PASS;
+ } else {
skb = orig_skb;
+ }

/* CSME wants the MAC header as well, push it back */
skb_push(skb, skb->data - skb_mac_header(skb));
--
2.35.1