2022-03-02 09:30:07

by CGEL

Subject: [PATCH V2] net/nfc/nci: fix infoleak in struct nci_set_config_param

From: "Minghao Chi (CGEL ZTE)" <[email protected]>

On 64-bit systems, struct nci_set_config_param has
an added padding of 7 bytes between struct members
id and len. Even though all struct members are initialized,
the 7-byte hole will contain data from the kernel stack.
This patch zeroes out struct nci_set_config_param before
usage, preventing infoleaks to userspace.

v1->v2:
-Modify the title.
-Add explanatory information.

Reported-by: Zeal Robot <[email protected]>
Signed-off-by: Minghao Chi (CGEL ZTE) <[email protected]>
---
net/nfc/nci/core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index d2537383a3e8..32be42be1152 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -641,6 +641,7 @@ int nci_set_config(struct nci_dev *ndev, __u8 id, size_t len, const __u8 *val)
if (!val || !len)
return 0;

+ memset(&param, 0x0, sizeof(param));
param.id = id;
param.len = len;
param.val = val;
--
2.25.1

2022-03-02 23:22:38

by Krzysztof Kozlowski

Subject: Re: [PATCH V2] net/nfc/nci: fix infoleak in struct nci_set_config_param

On 02/03/2022 04:33, [email protected] wrote:
> From: "Minghao Chi (CGEL ZTE)" <[email protected]>
>
> On 64-bit systems, struct nci_set_config_param has
> an added padding of 7 bytes between struct members
> id and len. Even though all struct members are initialized,
> the 7-byte hole will contain data from the kernel stack.
> This patch zeroes out struct nci_set_config_param before
> usage, preventing infoleaks to userspace.
>
> v1->v2:
> -Modify the title.
> -Add explanatory information.

Changelog goes below ---.

> Reported-by: Zeal Robot <[email protected]>

Why do you ignore the comment about missing report?

> Signed-off-by: Minghao Chi (CGEL ZTE) <[email protected]>
> ---
> net/nfc/nci/core.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
> index d2537383a3e8..32be42be1152 100644
> --- a/net/nfc/nci/core.c
> +++ b/net/nfc/nci/core.c
> @@ -641,6 +641,7 @@ int nci_set_config(struct nci_dev *ndev, __u8 id, size_t len, const __u8 *val)
> if (!val || !len)
> return 0;
>
> + memset(&param, 0x0, sizeof(param));

You ignored the comment here as well. That's not how a v2 should be
sent... if you don't agree with comments, we need to keep discussing.

> param.id = id;
> param.len = len;
> param.val = val;


Best regards,
Krzysztof