arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user

From: Will Deacon <will.deacon@arm.com>

commit f71c2ffcb20dd8626880747557014bb9a61eb90e upstream.

Like we've done for get_user and put_user, ensure that user pointers
are masked before invoking the underlying __arch_{clear,copy_*}_user
operations.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[v4.9: fixup for v4.9-style uaccess primitives]
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 0d4330c..1d047d6 100644 (file)
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -313,21 +313,20 @@ do {                                                                      \
 
 extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
 extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
-extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n);
-extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
+extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);
 
 static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
        kasan_check_write(to, n);
        check_object_size(to, n, false);
-       return __arch_copy_from_user(to, from, n);
+       return __arch_copy_from_user(to, __uaccess_mask_ptr(from), n);
 }
 
 static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
        kasan_check_read(from, n);
        check_object_size(from, n, true);
-       return __arch_copy_to_user(to, from, n);
+       return __arch_copy_to_user(__uaccess_mask_ptr(to), from, n);
 }
 
 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
@@ -355,22 +354,25 @@ static inline unsigned long __must_check copy_to_user(void __user *to, const voi
        return n;
 }
 
-static inline unsigned long __must_check copy_in_user(void __user *to, const void __user *from, unsigned long n)
+static inline unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
        if (access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n))
-               n = __copy_in_user(to, from, n);
+               n = __arch_copy_in_user(__uaccess_mask_ptr(to), __uaccess_mask_ptr(from), n);
        return n;
 }
+#define copy_in_user __copy_in_user
 
 #define __copy_to_user_inatomic __copy_to_user
 #define __copy_from_user_inatomic __copy_from_user
 
-static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned long n);
+static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)
 {
        if (access_ok(VERIFY_WRITE, to, n))
-               n = __clear_user(__uaccess_mask_ptr(to), n);
+               n = __arch_clear_user(__uaccess_mask_ptr(to), n);
        return n;
 }
+#define clear_user     __clear_user
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);
 

diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index e9c4dc9..66be504 100644 (file)
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c
@@ -37,8 +37,8 @@ EXPORT_SYMBOL(clear_page);
        /* user mem (segment) */
 EXPORT_SYMBOL(__arch_copy_from_user);
 EXPORT_SYMBOL(__arch_copy_to_user);
-EXPORT_SYMBOL(__clear_user);
-EXPORT_SYMBOL(__copy_in_user);
+EXPORT_SYMBOL(__arch_clear_user);
+EXPORT_SYMBOL(__arch_copy_in_user);
 
        /* physical memory */
 EXPORT_SYMBOL(memstart_addr);

diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 5d1cad3..efbf610 100644 (file)
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -24,7 +24,7 @@
 
        .text
 
-/* Prototype: int __clear_user(void *addr, size_t sz)
+/* Prototype: int __arch_clear_user(void *addr, size_t sz)
  * Purpose  : clear some user memory
  * Params   : addr - user memory address to clear
  *          : sz   - number of bytes to clear
@@ -32,7 +32,7 @@
  *
  * Alignment fixed up by hardware.
  */
-ENTRY(__clear_user)
+ENTRY(__arch_clear_user)
 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
            CONFIG_ARM64_PAN)
        mov     x2, x1                  // save the size for fixup return
@@ -57,7 +57,7 @@ uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
            CONFIG_ARM64_PAN)
        ret
-ENDPROC(__clear_user)
+ENDPROC(__arch_clear_user)
 
        .section .fixup,"ax"
        .align  2

diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index f7292dd..841bf8f 100644 (file)
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -67,7 +67,7 @@
        .endm
 
 end    .req    x5
-ENTRY(__copy_in_user)
+ENTRY(__arch_copy_in_user)
 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
            CONFIG_ARM64_PAN)
        add     end, x0, x2
@@ -76,7 +76,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
            CONFIG_ARM64_PAN)
        mov     x0, #0
        ret
-ENDPROC(__copy_in_user)
+ENDPROC(__arch_copy_in_user)
 
        .section .fixup,"ax"
        .align  2