ppdev: fix PPGETTIME/PPSETTIME ioctls

commit 998174042da229e2cf5841f574aba4a743e69650 upstream.

Going through the uses of timeval in the user space API,
I noticed two bugs in ppdev that were introduced in the y2038
conversion:

* The range check was accidentally moved from ppsettime to
  ppgettime

* On sparc64, the microseconds are in the other half of the
  64-bit word.

Fix both, and mark the fix for stable backports.

Cc: stable@vger.kernel.org
Fixes: 3b9ab374a1e6 ("ppdev: convert to y2038 safe")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191108203435.112759-8-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 336d02a488cc3712ffd77735b4a8152220de4e3f..3648727dfe836644d1019d9b02ae3a9fcd2512fc 100644 (file)
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -624,20 +624,27 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                if (copy_from_user(time32, argp, sizeof(time32)))
                        return -EFAULT;
 
+               if ((time32[0] < 0) || (time32[1] < 0))
+                       return -EINVAL;
+
                return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 
        case PPSETTIME64:
                if (copy_from_user(time64, argp, sizeof(time64)))
                        return -EFAULT;
 
+               if ((time64[0] < 0) || (time64[1] < 0))
+                       return -EINVAL;
+
+               if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
+                       time64[1] >>= 32;
+
                return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 
        case PPGETTIME32:
                jiffies_to_timespec64(pp->pdev->timeout, &ts);
                time32[0] = ts.tv_sec;
                time32[1] = ts.tv_nsec / NSEC_PER_USEC;
-               if ((time32[0] < 0) || (time32[1] < 0))
-                       return -EINVAL;
 
                if (copy_to_user(argp, time32, sizeof(time32)))
                        return -EFAULT;
@@ -648,8 +655,9 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                jiffies_to_timespec64(pp->pdev->timeout, &ts);
                time64[0] = ts.tv_sec;
                time64[1] = ts.tv_nsec / NSEC_PER_USEC;
-               if ((time64[0] < 0) || (time64[1] < 0))
-                       return -EINVAL;
+
+               if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
+                       time64[1] <<= 32;
 
                if (copy_to_user(argp, time64, sizeof(time64)))
                        return -EFAULT;