scsi: sg: check for valid direction before starting the request

Check for a valid direction before starting the request, otherwise we
risk running into an assertion in the scsi midlayer checking for valid
requests.

[mkp: fixed typo]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Link: http://www.spinics.net/lists/linux-scsi/msg104400.html
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Johannes Thumshirn 2017-04-07 09:34:15 +02:00 committed by Martin K. Petersen
parent 1bc0eb0446
commit 28676d869b

View File

@ -663,18 +663,14 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
* is a non-zero input_size, so emit a warning.
*/
if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
static char cmd[TASK_COMM_LEN];
if (strcmp(current->comm, cmd)) {
printk_ratelimited(KERN_WARNING
"sg_write: data in/out %d/%d bytes "
"for SCSI command 0x%x-- guessing "
"data in;\n program %s not setting "
"count and/or reply_len properly\n",
old_hdr.reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
strcpy(cmd, current->comm);
}
printk_ratelimited(KERN_WARNING
"sg_write: data in/out %d/%d bytes "
"for SCSI command 0x%x-- guessing "
"data in;\n program %s not setting "
"count and/or reply_len properly\n",
old_hdr.reply_len - (int)SZ_SG_HEADER,
input_size, (unsigned int) cmnd[0],
current->comm);
}
k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
return (k < 0) ? k : count;
@ -753,6 +749,29 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
return count;
}
static bool sg_is_valid_dxfer(sg_io_hdr_t *hp)
{
switch (hp->dxfer_direction) {
case SG_DXFER_NONE:
if (hp->dxferp || hp->dxfer_len > 0)
return false;
return true;
case SG_DXFER_TO_DEV:
case SG_DXFER_FROM_DEV:
case SG_DXFER_TO_FROM_DEV:
if (!hp->dxferp || hp->dxfer_len == 0)
return false;
return true;
case SG_DXFER_UNKNOWN:
if ((!hp->dxferp && hp->dxfer_len) ||
(hp->dxferp && hp->dxfer_len == 0))
return false;
return true;
default:
return false;
}
}
static int
sg_common_write(Sg_fd * sfp, Sg_request * srp,
unsigned char *cmnd, int timeout, int blocking)
@ -773,6 +792,9 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
"sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
(int) cmnd[0], (int) hp->cmd_len));
if (!sg_is_valid_dxfer(hp))
return -EINVAL;
k = sg_start_req(srp, cmnd);
if (k) {
SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,