2021-12-28 08:21:04

by Winkler, Tomas

Subject: [char-misc-next] mei: hbm: fix client dma reply status

From: Alexander Usyskin <[email protected]>

Don't blindly copy status value received from the firmware
into internal client status field,
It may be positive and ERR_PTR(ret) will translate it
into an invalid address and the caller will crash.

Put the error code into the client status on failure.

Fixes: 369aea845951 ("mei: implement client dma setup.")
Reported-by: Emmanuel Grumbach <[email protected]>
Cc: <[email protected]> # v5.11+
Acked-by: Tomas Winkler <[email protected]>
Signed-off-by: Alexander Usyskin <[email protected]>
Signed-off-by: Tomas Winkler <[email protected]>
---
drivers/misc/mei/hbm.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index be41843df75b..cebcca6d6d3e 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -672,10 +672,14 @@ static void mei_hbm_cl_dma_map_res(struct mei_device *dev,
if (!cl)
return;

- dev_dbg(dev->dev, "cl dma map result = %d\n", res->status);
- cl->status = res->status;
- if (!cl->status)
+ if (res->status) {
+ dev_err(dev->dev, "cl dma map failed %d\n", res->status);
+ cl->status = -EFAULT;
+ } else {
+ dev_dbg(dev->dev, "cl dma map succeeded\n");
cl->dma_mapped = 1;
+ cl->status = 0;
+ }
wake_up(&cl->wait);
}

@@ -698,10 +702,14 @@ static void mei_hbm_cl_dma_unmap_res(struct mei_device *dev,
if (!cl)
return;

- dev_dbg(dev->dev, "cl dma unmap result = %d\n", res->status);
- cl->status = res->status;
- if (!cl->status)
+ if (res->status) {
+ dev_err(dev->dev, "cl dma unmap failed %d\n", res->status);
+ cl->status = -EFAULT;
+ } else {
+ dev_dbg(dev->dev, "cl dma unmap succeeded\n");
cl->dma_mapped = 0;
+ cl->status = 0;
+ }
wake_up(&cl->wait);
}

--
2.31.1

2021-12-29 16:09:28

by Grumbach, Emmanuel

Subject: RE: [char-misc-next] mei: hbm: fix client dma reply status

>
> From: Alexander Usyskin <[email protected]>
>
> Don't blindly copy status value received from the firmware into internal client
> status field, It may be positive and ERR_PTR(ret) will translate it into an
> invalid address and the caller will crash.
>
> Put the error code into the client status on failure.
>
> Fixes: 369aea845951 ("mei: implement client dma setup.")
> Reported-by: Emmanuel Grumbach <[email protected]>
> Cc: <[email protected]> # v5.11+
> Acked-by: Tomas Winkler <[email protected]>
> Signed-off-by: Alexander Usyskin <[email protected]>
> Signed-off-by: Tomas Winkler <[email protected]>
>

Tested-by: : Emmanuel Grumbach <[email protected]>