2 files changed, 12 insertions, 1 deletions

diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 67ebf5751222..c439ec478216 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -349,6 +349,12 @@ static __user void *task_get_bounds_dir(struct task_struct *tsk)
                 return MPX_INVALID_BOUNDS_DIR;
 
         /*
+         * 32-bit binaries on 64-bit kernels are currently
+         * unsupported.
+         */
+        if (IS_ENABLED(CONFIG_X86_64) && test_thread_flag(TIF_IA32))
+                return MPX_INVALID_BOUNDS_DIR;
+        /*
          * The bounds directory pointer is stored in a register
          * only accessible if we first do an xsave.
          */
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index edf299c8ff6c..7ac68698406c 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -234,8 +234,13 @@ void pat_init(void)
               PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
 
         /* Boot CPU check */
-        if (!boot_pat_state)
+        if (!boot_pat_state) {
                 rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);
+                if (!boot_pat_state) {
+                        pat_disable("PAT read returns always zero, disabled.");
+                        return;
+                }
+        }
 
         wrmsrl(MSR_IA32_CR_PAT, pat);