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-rw-r--r--arch/x86/mm/maccess.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/mm/maccess.c b/arch/x86/mm/maccess.c
index 6993f026a..42115ac07 100644
--- a/arch/x86/mm/maccess.c
+++ b/arch/x86/mm/maccess.c
@@ -3,6 +3,8 @@
#include <linux/uaccess.h>
#include <linux/kernel.h>
+#include <asm/vsyscall.h>
+
#ifdef CONFIG_X86_64
bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
{
@@ -16,6 +18,14 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
return false;
/*
+ * Reading from the vsyscall page may cause an unhandled fault in
+ * certain cases. Though it is at an address above TASK_SIZE_MAX, it is
+ * usually considered as a user space address.
+ */
+ if (is_vsyscall_vaddr(vaddr))
+ return false;
+
+ /*
* Allow everything during early boot before 'x86_virt_bits'
* is initialized. Needed for instruction decoding in early
* exception handlers.