[MIPS] Add len and addr validation for MAP_FIXED mappings.

[linux-2.6-omap-h63xx.git] / arch / mips / kernel / syscall.c

diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index b95fe93dd646dad70290be9694bba0d7e37715c6..af1bdc897488acf4d71f65bc69579f58b03183ce 100644 (file)
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -73,7 +73,14 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
        task_size = STACK_TOP;
 
+       if (len > task_size)
+               return -ENOMEM;
+
        if (flags & MAP_FIXED) {
+               /* Even MAP_FIXED mappings must reside within task_size.  */
+               if (task_size - len < addr)
+                       return -EINVAL;
+
                /*
                 * We do not accept a shared mapping if it would violate
                 * cache aliasing constraints.
@@ -83,8 +90,6 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
                return addr;
        }
 
-       if (len > task_size)
-               return -ENOMEM;
        do_color_align = 0;
        if (filp || (flags & MAP_SHARED))
                do_color_align = 1;