diff mbox series

[v4,02/17] cxl/pci: Handle truncated CDAT header

Message ID 000e69cd163461c8b1bc2cf4155b6e25402c29c7.1678543498.git.lukas@wunner.de
State Accepted
Commit 34bafc747c54fb58c1908ec3116fa6137393e596
Headers show
Series Collection of DOE material | expand

Commit Message

Lukas Wunner March 11, 2023, 2:40 p.m. UTC
cxl_cdat_get_length() only checks whether the DOE response size is
sufficient for the Table Access response header (1 dword), but not the
succeeding CDAT header (1 dword length plus other fields).

It thus returns whatever uninitialized memory happens to be on the stack
if a truncated DOE response with only 1 dword was received.  Fix it.

Fixes: c97006046c79 ("cxl/port: Read CDAT table")
Reported-by: Ming Li <ming4.li@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ming Li <ming4.li@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: stable@vger.kernel.org # v6.0+
---
 drivers/cxl/core/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Kuppuswamy Sathyanarayanan March 13, 2023, 2:42 a.m. UTC | #1
On 3/11/23 6:40 AM, Lukas Wunner wrote:
> cxl_cdat_get_length() only checks whether the DOE response size is
> sufficient for the Table Access response header (1 dword), but not the
> succeeding CDAT header (1 dword length plus other fields).
> 
> It thus returns whatever uninitialized memory happens to be on the stack
> if a truncated DOE response with only 1 dword was received.  Fix it.
> 
> Fixes: c97006046c79 ("cxl/port: Read CDAT table")
> Reported-by: Ming Li <ming4.li@intel.com>
> Tested-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Reviewed-by: Ming Li <ming4.li@intel.com>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: stable@vger.kernel.org # v6.0+
> ---

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

>  drivers/cxl/core/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 49a99a84b6aa..87da8c935185 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -510,7 +510,7 @@ static int cxl_cdat_get_length(struct device *dev,
>  		return rc;
>  	}
>  	wait_for_completion(&t.c);
> -	if (t.task.rv < sizeof(__le32))
> +	if (t.task.rv < 2 * sizeof(__le32))
>  		return -EIO;

I think adding a comment about the size requirement would be helpful. But
it is up to you.

>  
>  	*length = le32_to_cpu(t.response_pl[1]);
diff mbox series

Patch

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 49a99a84b6aa..87da8c935185 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -510,7 +510,7 @@  static int cxl_cdat_get_length(struct device *dev,
 		return rc;
 	}
 	wait_for_completion(&t.c);
-	if (t.task.rv < sizeof(__le32))
+	if (t.task.rv < 2 * sizeof(__le32))
 		return -EIO;
 
 	*length = le32_to_cpu(t.response_pl[1]);