diff mbox

[v9,02/17] platform/x86: dell-wmi: increase severity of some failures

Message ID b2b395af98ab4aa5973742d4f03486b59bbe18f2.1508259916.git.mario.limonciello@dell.com (mailing list archive)
State Superseded, archived
Delegated to: Darren Hart
Headers show

Commit Message

Limonciello, Mario Oct. 17, 2017, 6:21 p.m. UTC 
There is a lot of error checking in place for the format of the WMI
descriptor buffer, but some of the potentially raised issues should
be considered critical failures.

If the buffer size or header don't match, this is a good indication
that the buffer format changed in a way that the rest of the data
should not be relied upon.

For the remaining data set vectors, continue to notate a warning
in undefined results, but as those are fields that the descriptor
intended to refer to other applications, don't fail if they're new
values.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
---
 drivers/platform/x86/dell-wmi.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

Pali Rohár Oct. 17, 2017, 6:42 p.m. UTC | #1 
On Tuesday 17 October 2017 13:21:46 Mario Limonciello wrote:
> There is a lot of error checking in place for the format of the WMI
> descriptor buffer, but some of the potentially raised issues should
> be considered critical failures.
> 
> If the buffer size or header don't match, this is a good indication
> that the buffer format changed in a way that the rest of the data
> should not be relied upon.
> 
> For the remaining data set vectors, continue to notate a warning
> in undefined results, but as those are fields that the descriptor
> intended to refer to other applications, don't fail if they're new
> values.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
> Reviewed-by: Edward O'Callaghan <quasisec@google.com>

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
diff mbox

Patch

diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
index 1fbef560ca67..2cfaaa8faf0a 100644
--- a/drivers/platform/x86/dell-wmi.c
+++ b/drivers/platform/x86/dell-wmi.c
@@ -657,17 +657,18 @@  static int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev)
 		dev_err(&wdev->dev,
 			"Dell descriptor buffer has invalid length (%d)\n",
 			obj->buffer.length);
-		if (obj->buffer.length < 16) {
-			ret = -EINVAL;
-			goto out;
-		}
+		ret = -EINVAL;
+		goto out;
 	}
 
 	buffer = (u32 *)obj->buffer.pointer;
 
-	if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
-		dev_warn(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n",
+	if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720) {
+		dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n",
 			8, buffer);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	if (buffer[2] != 0 && buffer[2] != 1)
 		dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%d)\n",