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Commit 4504c5cc authored by Mark Rutland's avatar Mark Rutland Committed by Greg Kroah-Hartman
Browse files

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: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin 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: default avatarGreg Hackmann <ghackmann@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4c03928f

arch/arm64/include/asm/uaccess.h

+10 −8
Original line number Original line Diff line number Diff line
@@ -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_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 __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 __arch_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);





static inline unsigned long __must_check __copy_from_user(void *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);

	kasan_check_write(to, n);

	check_object_size(to, n, false);

	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)

static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)

{

{

	kasan_check_read(from, n);

	kasan_check_read(from, n);

	check_object_size(from, n, true);

	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)

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;

	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))

	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;

	return n;

}

}

#define copy_in_user __copy_in_user





#define __copy_to_user_inatomic __copy_to_user

#define __copy_to_user_inatomic __copy_to_user

#define __copy_from_user_inatomic __copy_from_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))

	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;

	return n;

}

}

#define clear_user	__clear_user





extern long strncpy_from_user(char *dest, const char __user *src, long count);

extern long strncpy_from_user(char *dest, const char __user *src, long count);

arch/arm64/kernel/arm64ksyms.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -37,8 +37,8 @@ EXPORT_SYMBOL(clear_page); 
	/* user mem (segment) */

	/* user mem (segment) */

EXPORT_SYMBOL(__arch_copy_from_user);

EXPORT_SYMBOL(__arch_copy_from_user);

EXPORT_SYMBOL(__arch_copy_to_user);

EXPORT_SYMBOL(__arch_copy_to_user);

EXPORT_SYMBOL(__clear_user);

EXPORT_SYMBOL(__arch_clear_user);

EXPORT_SYMBOL(__copy_in_user);

EXPORT_SYMBOL(__arch_copy_in_user);





	/* physical memory */

	/* physical memory */

EXPORT_SYMBOL(memstart_addr);

EXPORT_SYMBOL(memstart_addr);

arch/arm64/lib/clear_user.S

+3 −3
Original line number Original line Diff line number Diff line
@@ -24,7 +24,7 @@ 




	.text

	.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

 * Purpose  : clear some user memory

 * Params   : addr - user memory address to clear

 * Params   : addr - user memory address to clear

 *          : sz   - number of bytes to clear

 *          : sz   - number of bytes to clear
@@ -32,7 +32,7 @@ 
 *

 *

 * Alignment fixed up by hardware.

 * Alignment fixed up by hardware.

 */

 */

ENTRY(__clear_user)

ENTRY(__arch_clear_user)

ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \

ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \

	    CONFIG_ARM64_PAN)

	    CONFIG_ARM64_PAN)

	mov	x2, x1			// save the size for fixup return

	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, \

ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \

	    CONFIG_ARM64_PAN)

	    CONFIG_ARM64_PAN)

	ret

	ret

ENDPROC(__clear_user)

ENDPROC(__arch_clear_user)





	.section .fixup,"ax"

	.section .fixup,"ax"

	.align	2

	.align	2

arch/arm64/lib/copy_in_user.S

+2 −2
Original line number Original line Diff line number Diff line
@@ -67,7 +67,7 @@ 
	.endm

	.endm





end	.req	x5

end	.req	x5

ENTRY(__copy_in_user)

ENTRY(__arch_copy_in_user)

ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \

ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \

	    CONFIG_ARM64_PAN)

	    CONFIG_ARM64_PAN)

	add	end, x0, x2

	add	end, x0, x2
@@ -76,7 +76,7 @@ ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \ 
	    CONFIG_ARM64_PAN)

	    CONFIG_ARM64_PAN)

	mov	x0, #0

	mov	x0, #0

	ret

	ret

ENDPROC(__copy_in_user)

ENDPROC(__arch_copy_in_user)





	.section .fixup,"ax"

	.section .fixup,"ax"

	.align	2

	.align	2