[PATCH v3 net-next 0/2] fix possible deadlock during WED attach

[PATCH v3 net-next 0/2] fix possible deadlock during WED attach

[Lorenzo Bianconi]

Fix a possible deadlock in mtk_wed_attach if mtk_wed_wo_init routine fails.
Check wo pointer is properly allocated before running mtk_wed_wo_reset() and
mtk_wed_wo_deinit().

Changes sice v2:
- add WARN_ON in mtk_wed_mcu_msg_update()
- split in two patches
Changes since v1:
- move wo pointer checks in __mtk_wed_detach()

Lorenzo Bianconi (2):
  net: ethernet: mtk_wed: fix some possible NULL pointer dereferences
  net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails

 drivers/net/ethernet/mediatek/mtk_wed.c     | 30 ++++++++++++++-------
 drivers/net/ethernet/mediatek/mtk_wed_mcu.c |  3 +++
 2 files changed, 23 insertions(+), 10 deletions(-)

-- 
2.38.1

[PATCH v3 net-next 1/2] net: ethernet: mtk_wed: fix some possible NULL pointer dereferences

[Lorenzo Bianconi]

Fix possible NULL pointer dereference in mtk_wed_detach routine checking
wo pointer is properly allocated before running mtk_wed_wo_reset() and
mtk_wed_wo_deinit().
Even if it is just a theoretical issue at the moment check wo pointer is
not NULL in mtk_wed_mcu_msg_update.
Moreover, honor mtk_wed_mcu_send_msg return value in mtk_wed_wo_reset()

Fixes: 799684448e3e ("net: ethernet: mtk_wed: introduce wed wo support")
Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/mediatek/mtk_wed.c     | 13 ++++++++-----
 drivers/net/ethernet/mediatek/mtk_wed_mcu.c |  3 +++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 06b6cc53fa02..4ef23eadd69e 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -174,9 +174,10 @@ mtk_wed_wo_reset(struct mtk_wed_device *dev)
 	mtk_wdma_tx_reset(dev);
 	mtk_wed_reset(dev, MTK_WED_RESET_WED);
 
-	mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO,
-			     MTK_WED_WO_CMD_CHANGE_STATE, &state,
-			     sizeof(state), false);
+	if (mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO,
+				 MTK_WED_WO_CMD_CHANGE_STATE, &state,
+				 sizeof(state), false))
+		return;
 
 	if (readx_poll_timeout(mtk_wed_wo_read_status, dev, val,
 			       val == MTK_WED_WOIF_DISABLE_DONE,
@@ -590,9 +591,11 @@ mtk_wed_detach(struct mtk_wed_device *dev)
 	mtk_wed_free_tx_rings(dev);
 
 	if (mtk_wed_get_rx_capa(dev)) {
-		mtk_wed_wo_reset(dev);
+		if (hw->wed_wo)
+			mtk_wed_wo_reset(dev);
 		mtk_wed_free_rx_rings(dev);
-		mtk_wed_wo_deinit(hw);
+		if (hw->wed_wo)
+			mtk_wed_wo_deinit(hw);
 	}
 
 	if (dev->wlan.bus_type == MTK_WED_BUS_PCIE) {
diff --git a/drivers/net/ethernet/mediatek/mtk_wed_mcu.c b/drivers/net/ethernet/mediatek/mtk_wed_mcu.c
index f9539e6233c9..6bad0d262f28 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed_mcu.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed_mcu.c
@@ -207,6 +207,9 @@ int mtk_wed_mcu_msg_update(struct mtk_wed_device *dev, int id, void *data,
 	if (dev->hw->version == 1)
 		return 0;
 
+	if (WARN_ON(!wo))
+		return -ENODEV;
+
 	return mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO, id, data, len,
 				    true);
 }
-- 
2.38.1

[PATCH v3 net-next 2/2] net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails

[Lorenzo Bianconi]

Introduce __mtk_wed_detach() in order to avoid a deadlock in
mtk_wed_attach routine if mtk_wed_wo_init fails since both
mtk_wed_attach and mtk_wed_detach run holding hw_lock mutex.

Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/mediatek/mtk_wed.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 4ef23eadd69e..a6271449617f 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -577,12 +577,10 @@ mtk_wed_deinit(struct mtk_wed_device *dev)
 }
 
 static void
-mtk_wed_detach(struct mtk_wed_device *dev)
+__mtk_wed_detach(struct mtk_wed_device *dev)
 {
 	struct mtk_wed_hw *hw = dev->hw;
 
-	mutex_lock(&hw_lock);
-
 	mtk_wed_deinit(dev);
 
 	mtk_wdma_rx_reset(dev);
@@ -615,6 +613,13 @@ mtk_wed_detach(struct mtk_wed_device *dev)
 	module_put(THIS_MODULE);
 
 	hw->wed_dev = NULL;
+}
+
+static void
+mtk_wed_detach(struct mtk_wed_device *dev)
+{
+	mutex_lock(&hw_lock);
+	__mtk_wed_detach(dev);
 	mutex_unlock(&hw_lock);
 }
 
@@ -1497,8 +1502,10 @@ mtk_wed_attach(struct mtk_wed_device *dev)
 		ret = mtk_wed_wo_init(hw);
 	}
 out:
-	if (ret)
-		mtk_wed_detach(dev);
+	if (ret) {
+		dev_err(dev->hw->dev, "failed to attach wed device\n");
+		__mtk_wed_detach(dev);
+	}
 unlock:
 	mutex_unlock(&hw_lock);
 
-- 
2.38.1

Re: [PATCH v3 net-next 1/2] net: ethernet: mtk_wed: fix some possible NULL pointer dereferences

[Leon Romanovsky]

On Wed, Dec 07, 2022 at 03:04:54PM +0100, Lorenzo Bianconi wrote:
> Fix possible NULL pointer dereference in mtk_wed_detach routine checking
> wo pointer is properly allocated before running mtk_wed_wo_reset() and
> mtk_wed_wo_deinit().
> Even if it is just a theoretical issue at the moment check wo pointer is
> not NULL in mtk_wed_mcu_msg_update.
> Moreover, honor mtk_wed_mcu_send_msg return value in mtk_wed_wo_reset()
> 
> Fixes: 799684448e3e ("net: ethernet: mtk_wed: introduce wed wo support")
> Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support")
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  drivers/net/ethernet/mediatek/mtk_wed.c     | 13 ++++++++-----
>  drivers/net/ethernet/mediatek/mtk_wed_mcu.c |  3 +++
>  2 files changed, 11 insertions(+), 5 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH v3 net-next 2/2] net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails

[Leon Romanovsky]

On Wed, Dec 07, 2022 at 03:04:55PM +0100, Lorenzo Bianconi wrote:
> Introduce __mtk_wed_detach() in order to avoid a deadlock in
> mtk_wed_attach routine if mtk_wed_wo_init fails since both
> mtk_wed_attach and mtk_wed_detach run holding hw_lock mutex.
> 
> Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support")
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  drivers/net/ethernet/mediatek/mtk_wed.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
> index 4ef23eadd69e..a6271449617f 100644
> --- a/drivers/net/ethernet/mediatek/mtk_wed.c
> +++ b/drivers/net/ethernet/mediatek/mtk_wed.c
> @@ -577,12 +577,10 @@ mtk_wed_deinit(struct mtk_wed_device *dev)
>  }
>  

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH v3 net-next 0/2] fix possible deadlock during WED attach

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed,  7 Dec 2022 15:04:53 +0100 you wrote:
> Fix a possible deadlock in mtk_wed_attach if mtk_wed_wo_init routine fails.
> Check wo pointer is properly allocated before running mtk_wed_wo_reset() and
> mtk_wed_wo_deinit().
> 
> Changes sice v2:
> - add WARN_ON in mtk_wed_mcu_msg_update()
> - split in two patches
> Changes since v1:
> - move wo pointer checks in __mtk_wed_detach()
> 
> [...]

Here is the summary with links:
  - [v3,net-next,1/2] net: ethernet: mtk_wed: fix some possible NULL pointer dereferences
    https://git.kernel.org/netdev/net-next/c/c79e0af5ae5e
  - [v3,net-next,2/2] net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails
    https://git.kernel.org/netdev/net-next/c/587585e1bbeb

You are awesome, thank you!
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