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-rw-r--r--arch/s390/lib/uaccess_pt.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index 97e03caf7825..dbdab3e7a1a6 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -78,11 +78,14 @@ static size_t copy_in_kernel(size_t count, void __user *to,
* contains the (negative) exception code.
*/
#ifdef CONFIG_64BIT
+
static unsigned long follow_table(struct mm_struct *mm,
unsigned long address, int write)
{
unsigned long *table = (unsigned long *)__pa(mm->pgd);
+ if (unlikely(address > mm->context.asce_limit - 1))
+ return -0x38UL;
switch (mm->context.asce_bits & _ASCE_TYPE_MASK) {
case _ASCE_TYPE_REGION1:
table = table + ((address >> 53) & 0x7ff);