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comedi: do_cmdtest_ioctl(): lift copyin/copyout into the caller

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-04-26 08:56:55 -04:00
parent 00035beeec
commit f0e4de5cd0
1 changed files with 22 additions and 23 deletions
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45
drivers/staging/comedi/comedi_fops.c
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@ -1856,49 +1856,39 @@ static int do_cmd_ioctl(struct comedi_device *dev,
* possibly modified comedi_cmd structure
*/
static int do_cmdtest_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *arg, void *file)
struct comedi_cmd *cmd, bool *copy, void *file)
{
struct comedi_cmd cmd;
struct comedi_subdevice *s;
unsigned int __user *user_chanlist;
int ret;
lockdep_assert_held(&dev->mutex);
if (copy_from_user(&cmd, arg, sizeof(cmd))) {
dev_dbg(dev->class_dev, "bad cmd address\n");
return -EFAULT;
}
/* get the user's cmd and do some simple validation */
ret = __comedi_get_user_cmd(dev, &cmd);
/* do some simple cmd validation */
ret = __comedi_get_user_cmd(dev, cmd);
if (ret)
return ret;
/* save user's chanlist pointer so it can be restored later */
user_chanlist = (unsigned int __user *)cmd.chanlist;
user_chanlist = (unsigned int __user *)cmd->chanlist;
s = &dev->subdevices[cmd.subdev];
s = &dev->subdevices[cmd->subdev];
/* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */
if (user_chanlist) {
/* load channel/gain list */
ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &cmd);
ret = __comedi_get_user_chanlist(dev, s, user_chanlist, cmd);
if (ret)
return ret;
}
ret = s->do_cmdtest(dev, s, &cmd);
ret = s->do_cmdtest(dev, s, cmd);
kfree(cmd.chanlist); /* free kernel copy of user chanlist */
kfree(cmd->chanlist); /* free kernel copy of user chanlist */
/* restore chanlist pointer before copying back */
cmd.chanlist = (unsigned int __force *)user_chanlist;
if (copy_to_user(arg, &cmd, sizeof(cmd))) {
dev_dbg(dev->class_dev, "bad cmd address\n");
ret = -EFAULT;
}
cmd->chanlist = (unsigned int __force *)user_chanlist;
*copy = true;
return ret;
}
@ -2220,10 +2210,19 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
case COMEDI_CMD:
rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
break;
case COMEDI_CMDTEST:
rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg,
file);
case COMEDI_CMDTEST: {
struct comedi_cmd cmd;
bool copy = false;
if (copy_from_user(&cmd, (void __user *)arg, sizeof(cmd))) {
rc = -EFAULT;
break;
}
rc = do_cmdtest_ioctl(dev, &cmd, &copy, file);
if (copy && copy_to_user((void __user *)arg, &cmd, sizeof(cmd)))
rc = -EFAULT;
break;
}
case COMEDI_INSNLIST: {
struct comedi_insnlist insnlist;
struct comedi_insn *insns = NULL;