From 388138764e2549520afd0b3b4e15de8deb592ff6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 25 Apr 2020 18:44:30 -0400 Subject: comedi: get rid of compat_alloc_user_space() mess in COMEDI_RANGEINFO compat Just take copy_from_user() out of do_rangeing_ioctl() into the caller and have compat_rangeinfo() build a native version and pass it to do_rangeinfo_ioctl() directly. Signed-off-by: Al Viro --- drivers/staging/comedi/comedi_fops.c | 43 ++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 24 deletions(-) (limited to 'drivers/staging/comedi/comedi_fops.c') diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index ab811735cd1b..d96dc85d8a98 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2210,9 +2210,14 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, rc = do_chaninfo_ioctl(dev, &it); break; } - case COMEDI_RANGEINFO: - rc = do_rangeinfo_ioctl(dev, (void __user *)arg); + case COMEDI_RANGEINFO: { + struct comedi_rangeinfo it; + if (copy_from_user(&it, (void __user *)arg, sizeof(it))) + rc = -EFAULT; + else + rc = do_rangeinfo_ioctl(dev, &it); break; + } case COMEDI_BUFINFO: rc = do_bufinfo_ioctl(dev, (struct comedi_bufinfo __user *)arg, @@ -2900,32 +2905,22 @@ static int compat_chaninfo(struct file *file, unsigned long arg) /* Handle 32-bit COMEDI_RANGEINFO ioctl. */ static int compat_rangeinfo(struct file *file, unsigned long arg) { - struct comedi_rangeinfo __user *rangeinfo; - struct comedi32_rangeinfo_struct __user *rangeinfo32; + struct comedi_file *cfp = file->private_data; + struct comedi_device *dev = cfp->dev; + struct comedi32_rangeinfo_struct rangeinfo32; + struct comedi_rangeinfo rangeinfo; int err; - union { - unsigned int uint; - compat_uptr_t uptr; - } temp; - - rangeinfo32 = compat_ptr(arg); - rangeinfo = compat_alloc_user_space(sizeof(*rangeinfo)); - /* Copy rangeinfo structure. */ - if (!access_ok(rangeinfo32, sizeof(*rangeinfo32)) || - !access_ok(rangeinfo, sizeof(*rangeinfo))) + if (copy_from_user(&rangeinfo32, compat_ptr(arg), sizeof(rangeinfo32))) return -EFAULT; + memset(&rangeinfo, 0, sizeof(rangeinfo)); + rangeinfo.range_type = rangeinfo32.range_type; + rangeinfo.range_ptr = compat_ptr(rangeinfo32.range_ptr); - err = 0; - err |= __get_user(temp.uint, &rangeinfo32->range_type); - err |= __put_user(temp.uint, &rangeinfo->range_type); - err |= __get_user(temp.uptr, &rangeinfo32->range_ptr); - err |= __put_user(compat_ptr(temp.uptr), &rangeinfo->range_ptr); - if (err) - return -EFAULT; - - return comedi_unlocked_ioctl(file, COMEDI_RANGEINFO, - (unsigned long)rangeinfo); + mutex_lock(&dev->mutex); + err = do_rangeinfo_ioctl(dev, &rangeinfo); + mutex_unlock(&dev->mutex); + return err; } /* Copy 32-bit cmd structure to native cmd structure. */ -- cgit