[MIPS] N32: Make sure pointer is good before passing it to sys_waitid().

After all we're calling sys_waitid() with fs set to KERNEL_DS ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 9996b6e84585..5f68b220c26d 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -230,6 +230,9 @@ sysn32_waitid(int which, compat_pid_t pid,
         long ret;
         mm_segment_t old_fs = get_fs();
 
+        if (!access_ok(VERIFY_WRITE, uinfo, sizeof(*uinfo)))
+                return -EFAULT;
+
         set_fs (KERNEL_DS);
         ret = sys_waitid(which, pid, uinfo, options,
                          uru ? (struct rusage __user *) &ru : NULL);