scsi: stex: Properly zero out the passthrough command structure

The passthrough structure is declared off of the stack, so it needs to be
set to zero before copied back to userspace to prevent any unintentional
data leakage.  Switch things to be statically allocated which will fill the
unused fields with 0 automatically.

Link: https://lore.kernel.org/r/YxrjN3OOw2HHl9tx@kroah.com
Cc: stable@kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: hdthky <hdthky0@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index e6420f2..8def242 100644 (file)
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -665,16 +665,17 @@ static int stex_queuecommand_lck(struct scsi_cmnd *cmd)
                return 0;
        case PASSTHRU_CMD:
                if (cmd->cmnd[1] == PASSTHRU_GET_DRVVER) {
-                       struct st_drvver ver;
+                       const struct st_drvver ver = {
+                               .major = ST_VER_MAJOR,
+                               .minor = ST_VER_MINOR,
+                               .oem = ST_OEM,
+                               .build = ST_BUILD_VER,
+                               .signature[0] = PASSTHRU_SIGNATURE,
+                               .console_id = host->max_id - 1,
+                               .host_no = hba->host->host_no,
+                       };
                        size_t cp_len = sizeof(ver);
 
-                       ver.major = ST_VER_MAJOR;
-                       ver.minor = ST_VER_MINOR;
-                       ver.oem = ST_OEM;
-                       ver.build = ST_BUILD_VER;
-                       ver.signature[0] = PASSTHRU_SIGNATURE;
-                       ver.console_id = host->max_id - 1;
-                       ver.host_no = hba->host->host_no;
                        cp_len = scsi_sg_copy_from_buffer(cmd, &ver, cp_len);
                        if (sizeof(ver) == cp_len)
                                cmd->result = DID_OK << 16;

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index bac55de..7d3622d 100644 (file)
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -201,7 +201,7 @@ static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
        for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
 
 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
-                                          void *buf, int buflen)
+                                          const void *buf, int buflen)
 {
        return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
                                   buf, buflen);