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-rw-r--r--arch/arm64/include/asm/memory.h2
-rw-r--r--arch/arm64/include/asm/uaccess.h10
2 files changed, 8 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index fb04f10a78ab..46c4c08a80a9 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -201,7 +201,7 @@ extern u64 vabits_user;
* pass on to access_ok(), for instance.
*/
#define untagged_addr(addr) \
- ((__typeof__(addr))sign_extend64((u64)(addr), 55))
+ ((__typeof__(addr))sign_extend64((__force u64)(addr), 55))
#ifdef CONFIG_KASAN_SW_TAGS
#define __tag_shifted(tag) ((u64)(tag) << 56)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 5a1c32260c1f..a138e3b4f717 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -62,6 +62,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
{
unsigned long ret, limit = current_thread_info()->addr_limit;
+ addr = untagged_addr(addr);
+
__chk_user_ptr(addr);
asm volatile(
// A + B <= C + 1 for all A,B,C, in four easy steps:
@@ -215,7 +217,8 @@ static inline void uaccess_enable_not_uao(void)
/*
* Sanitise a uaccess pointer such that it becomes NULL if above the
- * current addr_limit.
+ * current addr_limit. In case the pointer is tagged (has the top byte set),
+ * untag the pointer before checking.
*/
#define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr)
static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
@@ -223,10 +226,11 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
void __user *safe_ptr;
asm volatile(
- " bics xzr, %1, %2\n"
+ " bics xzr, %3, %2\n"
" csel %0, %1, xzr, eq\n"
: "=&r" (safe_ptr)
- : "r" (ptr), "r" (current_thread_info()->addr_limit)
+ : "r" (ptr), "r" (current_thread_info()->addr_limit),
+ "r" (untagged_addr(ptr))
: "cc");
csdb();