mm: make fixup_user_fault() check the vma access rights too

[deliverable/linux.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index d0f0bef3be488af9eb9406cc5d28272093abb5a6..93e332d5ed778f4185c3a0a791edc0928b78d198 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1955,12 +1955,17 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
                     unsigned long address, unsigned int fault_flags)
 {
        struct vm_area_struct *vma;
+       vm_flags_t vm_flags;
        int ret;
 
        vma = find_extend_vma(mm, address);
        if (!vma || address < vma->vm_start)
                return -EFAULT;
 
+       vm_flags = (fault_flags & FAULT_FLAG_WRITE) ? VM_WRITE : VM_READ;
+       if (!(vm_flags & vma->vm_flags))
+               return -EFAULT;
+
        ret = handle_mm_fault(mm, vma, address, fault_flags);
        if (ret & VM_FAULT_ERROR) {
                if (ret & VM_FAULT_OOM)