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Subject[patch 07/22] m32r: security fix of {get, put}_user macros

-stable review patch. If anyone has any objections, please let us know.

------------------
From: Hirokazu Takata <takata@linux-m32r.org>

Update {get,put}_user macros for m32r kernel.
- Modify get_user to use __get_user_asm macro, instead of __get_user_x macro.
- Remove arch/m32r/lib/{get,put}user.S.
- Some cosmetic updates.
I would like to thank NIIBE Yutaka for his reporting about the m32r kernel's
security problem in {get,put}_user macros.
There were no address checking for user space access in {get,put}_user macros.
;-)
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: NIIBE Yutaka <gniibe@fsij.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/m32r/kernel/m32r_ksyms.c | 4
arch/m32r/lib/Makefile | 4
arch/m32r/lib/getuser.S | 88 -------------
arch/m32r/lib/putuser.S | 84 -------------
include/asm-m32r/uaccess.h | 266 ++++++++++++++++++------------------------
5 files changed, 117 insertions(+), 329 deletions(-)
--- linux-2.6.16.5.orig/arch/m32r/kernel/m32r_ksyms.c
+++ linux-2.6.16.5/arch/m32r/kernel/m32r_ksyms.c
@@ -38,10 +38,6 @@ EXPORT_SYMBOL(__udelay);
EXPORT_SYMBOL(__delay);
EXPORT_SYMBOL(__const_udelay);

-EXPORT_SYMBOL(__get_user_1);
-EXPORT_SYMBOL(__get_user_2);
-EXPORT_SYMBOL(__get_user_4);
-
EXPORT_SYMBOL(strpbrk);
EXPORT_SYMBOL(strstr);

--- linux-2.6.16.5.orig/arch/m32r/lib/Makefile
+++ linux-2.6.16.5/arch/m32r/lib/Makefile
@@ -2,6 +2,6 @@
# Makefile for M32R-specific library files..
#

-lib-y := checksum.o ashxdi3.o memset.o memcpy.o getuser.o \
- putuser.o delay.o strlen.o usercopy.o csum_partial_copy.o
+lib-y := checksum.o ashxdi3.o memset.o memcpy.o \
+ delay.o strlen.o usercopy.o csum_partial_copy.o

--- linux-2.6.16.5.orig/arch/m32r/lib/getuser.S
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * __get_user functions.
- *
- * (C) Copyright 2001 Hirokazu Takata
- *
- * These functions have a non-standard call interface
- * to make them more efficient, especially as they
- * return an error value in addition to the "real"
- * return value.
- */
-
-#include <linux/config.h>
-
-/*
- * __get_user_X
- *
- * Inputs: r0 contains the address
- *
- * Outputs: r0 is error code (0 or -EFAULT)
- * r1 contains zero-extended value
- *
- * These functions should not modify any other registers,
- * as they get called from within inline assembly.
- */
-
-#ifdef CONFIG_ISA_DUAL_ISSUE
-
- .text
- .balign 4
- .globl __get_user_1
-__get_user_1:
-1: ldub r1, @r0 || ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __get_user_2
-__get_user_2:
-2: lduh r1, @r0 || ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __get_user_4
-__get_user_4:
-3: ld r1, @r0 || ldi r0, #0
- jmp r14
-
-bad_get_user:
- ldi r1, #0 || ldi r0, #-14
- jmp r14
-
-#else /* not CONFIG_ISA_DUAL_ISSUE */
-
- .text
- .balign 4
- .globl __get_user_1
-__get_user_1:
-1: ldub r1, @r0
- ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __get_user_2
-__get_user_2:
-2: lduh r1, @r0
- ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __get_user_4
-__get_user_4:
-3: ld r1, @r0
- ldi r0, #0
- jmp r14
-
-bad_get_user:
- ldi r1, #0
- ldi r0, #-14
- jmp r14
-
-#endif /* not CONFIG_ISA_DUAL_ISSUE */
-
-.section __ex_table,"a"
- .long 1b,bad_get_user
- .long 2b,bad_get_user
- .long 3b,bad_get_user
-.previous
-
- .end
--- linux-2.6.16.5.orig/arch/m32r/lib/putuser.S
+++ /dev/null
@@ -1,84 +0,0 @@
-/*
- * __put_user functions.
- *
- * (C) Copyright 1998 Linus Torvalds
- * (C) Copyright 2001 Hirokazu Takata
- *
- * These functions have a non-standard call interface
- * to make them more efficient.
- */
-
-#include <linux/config.h>
-
-/*
- * __put_user_X
- *
- * Inputs: r0 contains the address
- * r1 contains the value
- *
- * Outputs: r0 is error code (0 or -EFAULT)
- * r1 is corrupted (will contain "current_task").
- *
- * These functions should not modify any other registers,
- * as they get called from within inline assembly.
- */
-
-#ifdef CONFIG_ISA_DUAL_ISSUE
-
- .text
- .balign 4
- .globl __put_user_1
-__put_user_1:
-1: stb r1, @r0 || ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __put_user_2
-__put_user_2:
-2: sth r1, @r0 || ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __put_user_4
-__put_user_4:
-3: st r1, @r0 || ldi r0, #0
- jmp r14
-
-bad_put_user:
- ldi r0, #-14 || jmp r14
-
-#else /* not CONFIG_ISA_DUAL_ISSUE */
-
- .text
- .balign 4
- .globl __put_user_1
-__put_user_1:
-1: stb r1, @r0
- ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __put_user_2
-__put_user_2:
-2: sth r1, @r0
- ldi r0, #0
- jmp r14
-
- .balign 4
- .globl __put_user_4
-__put_user_4:
-3: st r1, @r0
- ldi r0, #0
- jmp r14
-
-bad_put_user:
- ldi r0, #-14
- jmp r14
-
-#endif /* not CONFIG_ISA_DUAL_ISSUE */
-
-.section __ex_table,"a"
- .long 1b,bad_put_user
- .long 2b,bad_put_user
- .long 3b,bad_put_user
-.previous
--- linux-2.6.16.5.orig/include/asm-m32r/uaccess.h
+++ linux-2.6.16.5/include/asm-m32r/uaccess.h
@@ -5,17 +5,9 @@
* linux/include/asm-m32r/uaccess.h
*
* M32R version.
- * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
+ * Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/

-#undef UACCESS_DEBUG
-
-#ifdef UACCESS_DEBUG
-#define UAPRINTK(args...) printk(args)
-#else
-#define UAPRINTK(args...)
-#endif /* UACCESS_DEBUG */
-
/*
* User space memory access functions
*/
@@ -38,27 +30,29 @@
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })

#ifdef CONFIG_MMU
+
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
-#else
-#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
-#define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
-#endif /* CONFIG_MMU */
-
#define get_ds() (KERNEL_DS)
-#ifdef CONFIG_MMU
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
-#else
+
+#else /* not CONFIG_MMU */
+
+#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
+#define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
+#define get_ds() (KERNEL_DS)
+
static inline mm_segment_t get_fs(void)
{
- return USER_DS;
+ return USER_DS;
}

static inline void set_fs(mm_segment_t s)
{
}
-#endif /* CONFIG_MMU */
+
+#endif /* not CONFIG_MMU */

#define segment_eq(a,b) ((a).seg == (b).seg)

@@ -83,9 +77,9 @@ static inline void set_fs(mm_segment_t s
" subx %0, %0\n" \
" cmpu %4, %1\n" \
" subx %0, %5\n" \
- : "=&r"(flag), "=r"(sum) \
- : "1"(addr), "r"((int)(size)), \
- "r"(current_thread_info()->addr_limit.seg), "r"(0) \
+ : "=&r" (flag), "=r" (sum) \
+ : "1" (addr), "r" ((int)(size)), \
+ "r" (current_thread_info()->addr_limit.seg), "r" (0) \
: "cbit" ); \
flag; })

@@ -113,10 +107,10 @@ static inline void set_fs(mm_segment_t s
#else
static inline int access_ok(int type, const void *addr, unsigned long size)
{
- extern unsigned long memory_start, memory_end;
- unsigned long val = (unsigned long)addr;
+ extern unsigned long memory_start, memory_end;
+ unsigned long val = (unsigned long)addr;

- return ((val >= memory_start) && ((val + size) < memory_end));
+ return ((val >= memory_start) && ((val + size) < memory_end));
}
#endif /* CONFIG_MMU */

@@ -155,39 +149,6 @@ extern int fixup_exception(struct pt_reg
* accesses to the same area of user memory).
*/

-extern void __get_user_1(void);
-extern void __get_user_2(void);
-extern void __get_user_4(void);
-
-#ifndef MODULE
-#define __get_user_x(size,ret,x,ptr) \
- __asm__ __volatile__( \
- " mv r0, %0\n" \
- " mv r1, %1\n" \
- " bl __get_user_" #size "\n" \
- " mv %0, r0\n" \
- " mv %1, r1\n" \
- : "=r"(ret), "=r"(x) \
- : "0"(ptr) \
- : "r0", "r1", "r14" )
-#else /* MODULE */
-/*
- * Use "jl" instead of "bl" for MODULE
- */
-#define __get_user_x(size,ret,x,ptr) \
- __asm__ __volatile__( \
- " mv r0, %0\n" \
- " mv r1, %1\n" \
- " seth lr, #high(__get_user_" #size ")\n" \
- " or3 lr, lr, #low(__get_user_" #size ")\n" \
- " jl lr\n" \
- " mv %0, r0\n" \
- " mv %1, r1\n" \
- : "=r"(ret), "=r"(x) \
- : "0"(ptr) \
- : "r0", "r1", "r14" )
-#endif
-
/* Careful: we have to cast the result to the type of the pointer for sign
reasons */
/**
@@ -208,20 +169,7 @@ extern void __get_user_4(void);
* On error, the variable @x is set to zero.
*/
#define get_user(x,ptr) \
-({ int __ret_gu; \
- unsigned long __val_gu; \
- __chk_user_ptr(ptr); \
- switch(sizeof (*(ptr))) { \
- case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
- case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
- case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
- default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \
- } \
- (x) = (__typeof__(*(ptr)))__val_gu; \
- __ret_gu; \
-})
-
-extern void __put_user_bad(void);
+ __get_user_check((x),(ptr),sizeof(*(ptr)))

/**
* put_user: - Write a simple value into user space.
@@ -240,8 +188,7 @@ extern void __put_user_bad(void);
* Returns zero on success, or -EFAULT on error.
*/
#define put_user(x,ptr) \
- __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
-
+ __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))

/**
* __get_user: - Get a simple variable from user space, with less checking.
@@ -264,8 +211,64 @@ extern void __put_user_bad(void);
* On error, the variable @x is set to zero.
*/
#define __get_user(x,ptr) \
- __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
+ __get_user_nocheck((x),(ptr),sizeof(*(ptr)))

+#define __get_user_nocheck(x,ptr,size) \
+({ \
+ long __gu_err = 0; \
+ unsigned long __gu_val; \
+ might_sleep(); \
+ __get_user_size(__gu_val,(ptr),(size),__gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+#define __get_user_check(x,ptr,size) \
+({ \
+ long __gu_err = -EFAULT; \
+ unsigned long __gu_val = 0; \
+ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
+ might_sleep(); \
+ if (access_ok(VERIFY_READ,__gu_addr,size)) \
+ __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
+ (x) = (__typeof__(*(ptr)))__gu_val; \
+ __gu_err; \
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x,ptr,size,retval) \
+do { \
+ retval = 0; \
+ __chk_user_ptr(ptr); \
+ switch (size) { \
+ case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
+ case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
+ case 4: __get_user_asm(x,ptr,retval,""); break; \
+ default: (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_asm(x, addr, err, itype) \
+ __asm__ __volatile__( \
+ " .fillinsn\n" \
+ "1: ld"itype" %1,@%2\n" \
+ " .fillinsn\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ " .balign 4\n" \
+ "3: ldi %0,%3\n" \
+ " seth r14,#high(2b)\n" \
+ " or3 r14,r14,#low(2b)\n" \
+ " jmp r14\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .balign 4\n" \
+ " .long 1b,3b\n" \
+ ".previous" \
+ : "=&r" (err), "=&r" (x) \
+ : "r" (addr), "i" (-EFAULT), "0" (err) \
+ : "r14", "memory")

/**
* __put_user: - Write a simple value into user space, with less checking.
@@ -287,11 +290,13 @@ extern void __put_user_bad(void);
* Returns zero on success, or -EFAULT on error.
*/
#define __put_user(x,ptr) \
- __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
+ __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
+

#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err; \
+ might_sleep(); \
__put_user_size((x),(ptr),(size),__pu_err); \
__pu_err; \
})
@@ -308,28 +313,28 @@ extern void __put_user_bad(void);
})

#if defined(__LITTLE_ENDIAN__)
-#define __put_user_u64(x, addr, err) \
- __asm__ __volatile__( \
- " .fillinsn\n" \
- "1: st %L1,@%2\n" \
- " .fillinsn\n" \
- "2: st %H1,@(4,%2)\n" \
- " .fillinsn\n" \
- "3:\n" \
- ".section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "4: ldi %0,%3\n" \
- " seth r14,#high(3b)\n" \
- " or3 r14,r14,#low(3b)\n" \
- " jmp r14\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- " .balign 4\n" \
- " .long 1b,4b\n" \
- " .long 2b,4b\n" \
- ".previous" \
- : "=&r"(err) \
- : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
+#define __put_user_u64(x, addr, err) \
+ __asm__ __volatile__( \
+ " .fillinsn\n" \
+ "1: st %L1,@%2\n" \
+ " .fillinsn\n" \
+ "2: st %H1,@(4,%2)\n" \
+ " .fillinsn\n" \
+ "3:\n" \
+ ".section .fixup,\"ax\"\n" \
+ " .balign 4\n" \
+ "4: ldi %0,%3\n" \
+ " seth r14,#high(3b)\n" \
+ " or3 r14,r14,#low(3b)\n" \
+ " jmp r14\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .balign 4\n" \
+ " .long 1b,4b\n" \
+ " .long 2b,4b\n" \
+ ".previous" \
+ : "=&r" (err) \
+ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")

#elif defined(__BIG_ENDIAN__)
@@ -353,13 +358,15 @@ extern void __put_user_bad(void);
" .long 1b,4b\n" \
" .long 2b,4b\n" \
".previous" \
- : "=&r"(err) \
- : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
+ : "=&r" (err) \
+ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")
#else
#error no endian defined
#endif

+extern void __put_user_bad(void);
+
#define __put_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
@@ -398,52 +405,8 @@ struct __large_struct { unsigned long bu
" .balign 4\n" \
" .long 1b,3b\n" \
".previous" \
- : "=&r"(err) \
- : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
- : "r14", "memory")
-
-#define __get_user_nocheck(x,ptr,size) \
-({ \
- long __gu_err; \
- unsigned long __gu_val; \
- __get_user_size(__gu_val,(ptr),(size),__gu_err); \
- (x) = (__typeof__(*(ptr)))__gu_val; \
- __gu_err; \
-})
-
-extern long __get_user_bad(void);
-
-#define __get_user_size(x,ptr,size,retval) \
-do { \
- retval = 0; \
- __chk_user_ptr(ptr); \
- switch (size) { \
- case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
- case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
- case 4: __get_user_asm(x,ptr,retval,""); break; \
- default: (x) = __get_user_bad(); \
- } \
-} while (0)
-
-#define __get_user_asm(x, addr, err, itype) \
- __asm__ __volatile__( \
- " .fillinsn\n" \
- "1: ld"itype" %1,@%2\n" \
- " .fillinsn\n" \
- "2:\n" \
- ".section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "3: ldi %0,%3\n" \
- " seth r14,#high(2b)\n" \
- " or3 r14,r14,#low(2b)\n" \
- " jmp r14\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- " .balign 4\n" \
- " .long 1b,3b\n" \
- ".previous" \
- : "=&r"(err), "=&r"(x) \
- : "r"(addr), "i"(-EFAULT), "0"(err) \
+ : "=&r" (err) \
+ : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err) \
: "r14", "memory")

/*
@@ -453,7 +416,6 @@ do { \
* anything, so this is accurate.
*/

-
/*
* Copy To/From Userspace
*/
@@ -511,8 +473,9 @@ do { \
" .long 2b,9b\n" \
" .long 3b,9b\n" \
".previous\n" \
- : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
- : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
+ : "=&r" (__dst), "=&r" (__src), "=&r" (size), \
+ "=&r" (__c) \
+ : "0" (to), "1" (from), "2" (size), "3" (size / 4) \
: "r14", "memory"); \
} while (0)

@@ -573,8 +536,9 @@ do { \
" .long 2b,7b\n" \
" .long 3b,7b\n" \
".previous\n" \
- : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
- : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
+ : "=&r" (__dst), "=&r" (__src), "=&r" (size), \
+ "=&r" (__c) \
+ : "0" (to), "1" (from), "2" (size), "3" (size / 4) \
: "r14", "memory"); \
} while (0)

@@ -676,7 +640,7 @@ unsigned long __generic_copy_from_user(v
#define copy_from_user(to,from,n) \
({ \
might_sleep(); \
-__generic_copy_from_user((to),(from),(n)); \
+ __generic_copy_from_user((to),(from),(n)); \
})

long __must_check strncpy_from_user(char *dst, const char __user *src,
--
-
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