1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index f4df6e7c718b..847d12945998 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -16,6 +16,8 @@
 do {                                                                       \
         long __d0, __d1, __d2;                                             \
         might_sleep();                                                     \
+        if (current->mm)                                                   \
+                might_lock_read(&current->mm->mmap_sem);                   \
         __asm__ __volatile__(                                              \
                 "       testq %1,%1\n"                                     \
                 "       jz 2f\n"                                           \
@@ -65,6 +67,8 @@ unsigned long __clear_user(void __user *addr, unsigned long size)
 {
         long __d0;
         might_sleep();
+        if (current->mm)
+                might_lock_read(&current->mm->mmap_sem);
         /* no memory constraint because it doesn't change any memory gcc knows
            about */
         asm volatile(