[PATCH v3] smb2: fix uninitialized variable bug in smb2_ioctl_query_info

[PATCH v3] smb2: fix uninitialized variable bug in smb2_ioctl_query_info

[Gustavo A. R. Silva]

There is a potential execution path in which variable *resp_buftype*
is passed as an argument to function free_rsp_buf(), in which it is
used in a comparison without being properly initialized previously.

Fix this by initializing variable *resp_buftype* to CIFS_NO_BUFFER
in order to avoid unpredictable or unintended results.

Addresses-Coverity-ID: 1473971 ("Uninitialized scalar variable")
Fixes: c5d25bdb2967 ("cifs: add IOCTL for QUERY_INFO passthrough to userspace")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
Changes in v3:
 - Initialize resp_buftype to CIFS_NO_BUFFER instead of to -1.
   Thanks to Ronnie Sahlberg for pointing this out.

Changes in v2:
 - Fix Coverity and Fixes tag.
 - Update commit log.

 fs/cifs/smb2ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index c6c6450d..8472cb0 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1133,7 +1133,7 @@ smb2_ioctl_query_info(const unsigned int xid,
 	struct smb_rqst rqst;
 	struct kvec iov[1];
 	struct kvec rsp_iov;
-	int resp_buftype;
+	int resp_buftype = CIFS_NO_BUFFER;
 	struct smb2_query_info_rsp *rsp = NULL;
 	void *buffer;
 
-- 
2.7.4

Re: [PATCH v3] smb2: fix uninitialized variable bug in smb2_ioctl_query_info

[Steve French]

Added Ronnie's reviewed-by and pushed to cifs-2.6.git for-next
On Tue, Oct 9, 2018 at 5:27 PM Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
>
> There is a potential execution path in which variable *resp_buftype*
> is passed as an argument to function free_rsp_buf(), in which it is
> used in a comparison without being properly initialized previously.
>
> Fix this by initializing variable *resp_buftype* to CIFS_NO_BUFFER
> in order to avoid unpredictable or unintended results.
>
> Addresses-Coverity-ID: 1473971 ("Uninitialized scalar variable")
> Fixes: c5d25bdb2967 ("cifs: add IOCTL for QUERY_INFO passthrough to userspace")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> Changes in v3:
>  - Initialize resp_buftype to CIFS_NO_BUFFER instead of to -1.
>    Thanks to Ronnie Sahlberg for pointing this out.
>
> Changes in v2:
>  - Fix Coverity and Fixes tag.
>  - Update commit log.
>
>  fs/cifs/smb2ops.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index c6c6450d..8472cb0 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1133,7 +1133,7 @@ smb2_ioctl_query_info(const unsigned int xid,
>         struct smb_rqst rqst;
>         struct kvec iov[1];
>         struct kvec rsp_iov;
> -       int resp_buftype;
> +       int resp_buftype = CIFS_NO_BUFFER;
>         struct smb2_query_info_rsp *rsp = NULL;
>         void *buffer;
>
> --
> 2.7.4
>


-- 
Thanks,

Steve