2023-08-18 16:42:13

by Daniel Golle

Subject: [PATCH net] net: ethernet: mtk_eth_soc: fix NULL pointer on hw reset

When a hardware reset is triggered on devices not initializing WED the
calls to mtk_wed_fe_reset and mtk_wed_fe_reset_complete dereference a
pointer on uninitialized stack memory.
Initialize the hw_list will 0s and break out of both functions in case
a hw_list entry is 0.

Fixes: 08a764a7c51b ("net: ethernet: mtk_wed: add reset/reset_complete callbacks")
Signed-off-by: Daniel Golle <[email protected]>
---
drivers/net/ethernet/mediatek/mtk_wed.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 00aeee0d5e45f..d14f5137379b9 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -41,7 +41,7 @@
#define MTK_WED_RRO_QUE_CNT 8192
#define MTK_WED_MIOD_ENTRY_CNT 128

-static struct mtk_wed_hw *hw_list[2];
+static struct mtk_wed_hw *hw_list[2] = {};
static DEFINE_MUTEX(hw_lock);

struct mtk_wed_flow_block_priv {
@@ -222,9 +222,13 @@ void mtk_wed_fe_reset(void)

for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
struct mtk_wed_hw *hw = hw_list[i];
- struct mtk_wed_device *dev = hw->wed_dev;
+ struct mtk_wed_device *dev;
int err;

+ if (!hw)
+ break;
+
+ dev = hw->wed_dev;
if (!dev || !dev->wlan.reset)
continue;

@@ -245,8 +249,12 @@ void mtk_wed_fe_reset_complete(void)

for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
struct mtk_wed_hw *hw = hw_list[i];
- struct mtk_wed_device *dev = hw->wed_dev;
+ struct mtk_wed_device *dev;
+
+ if (!hw)
+ break;

+ dev = hw->wed_dev;
if (!dev || !dev->wlan.reset_complete)
continue;

--
2.41.0

2023-08-20 13:28:51

by Jakub Kicinski

Subject: Re: [PATCH net] net: ethernet: mtk_eth_soc: fix NULL pointer on hw reset

On Thu, 17 Aug 2023 13:01:11 +0100 Daniel Golle wrote:
> Initialize the hw_list will 0s and break out of both functions in case
> a hw_list entry is 0.

Static variables are always initialized to 0, I don't think that part
is need.
--
pw-bot: cr