[PATCH 6.0 13/34] scsi: stex: Properly zero out the passthrough command structure

Greg Kroah-Hartman
2022-10-13T18:08:13Z

From: Linus Torvalds <torvalds@linux-foundation.org>

commit 6022f210461fef67e6e676fd8544ca02d1bcfa7a upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/stex.c | 17 +++++++++--------
include/scsi/scsi_cmnd.h | 2 +-
2 files changed, 10 insertions(+), 9 deletions(-)

--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -665,16 +665,17 @@ static int stex_queuecommand_lck(struct
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;
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -201,7 +201,7 @@ static inline unsigned int scsi_get_resi
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);