smb2: fix uninitialized variable bug in smb2_ioctl_query_info

PATCH In review Gustavo A. R. Silva 2 participants 2 messages Oct 9, 2018

Subsystems (2)

SMB client (CIFS) Kernel SMB3 server (ksmbd)

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Gustavo A. R. Silva

author

2018-10-09 22:02 UTC #0 lore raw

PATCH v3 1/1 smb2: fix uninitialized variable bug in smb2_ioctl_query_info

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 <[email protected]>

---
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(-)

fs/cifs/smb2ops.c +1 -1

index c6c6450d..8472cb0 100644
@@ -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;

Signature · 1 line

2.7.4

Steve French

2018-10-09 23:11 UTC #1 lore raw

Added Ronnie's reviewed-by and pushed to cifs-2.6.git for-next

Quoted 39 lines · 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 <[email protected]>
---
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(-)
fs/cifs/smb2ops.c +1 -2
index c6c6450d..8472cb0 100644
@@ -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

Signature · 3 lines

Thanks,

Steve