sparc: Add full proper error handling to strncpy_from_user().
Linus removed the end-of-address-space hackery from fs/namei.c:do_getname() so we really have to validate these edge conditions and cannot cheat any more (as x86 used to as well). Move to a common C implementation like x86 did. And if both src and dst are sufficiently aligned we'll do word at a time copies and checks as well. Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
parent
29af0ebaa2
commit
ff06dffbc8
8 changed files with 136 additions and 198 deletions
|
|
@ -5,4 +5,7 @@
|
|||
#else
|
||||
#include <asm/uaccess_32.h>
|
||||
#endif
|
||||
|
||||
extern long strncpy_from_user(char *dest, const char __user *src, long count);
|
||||
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -304,16 +304,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long n)
|
|||
return n;
|
||||
}
|
||||
|
||||
extern long __strncpy_from_user(char *dest, const char __user *src, long count);
|
||||
|
||||
static inline long strncpy_from_user(char *dest, const char __user *src, long count)
|
||||
{
|
||||
if (__access_ok((unsigned long) src, count))
|
||||
return __strncpy_from_user(dest, src, count);
|
||||
else
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
extern long __strlen_user(const char __user *);
|
||||
extern long __strnlen_user(const char __user *, long len);
|
||||
|
||||
|
|
|
|||
|
|
@ -257,10 +257,6 @@ extern unsigned long __must_check __clear_user(void __user *, unsigned long);
|
|||
|
||||
#define clear_user __clear_user
|
||||
|
||||
extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
|
||||
|
||||
#define strncpy_from_user __strncpy_from_user
|
||||
|
||||
extern long __strlen_user(const char __user *);
|
||||
extern long __strnlen_user(const char __user *, long len);
|
||||
|
||||
|
|
|
|||
|
|
@ -10,7 +10,7 @@ lib-y += strlen.o
|
|||
lib-y += checksum_$(BITS).o
|
||||
lib-$(CONFIG_SPARC32) += blockops.o
|
||||
lib-y += memscan_$(BITS).o memcmp.o strncmp_$(BITS).o
|
||||
lib-y += strncpy_from_user_$(BITS).o strlen_user_$(BITS).o
|
||||
lib-y += strlen_user_$(BITS).o
|
||||
lib-$(CONFIG_SPARC32) += divdi3.o udivdi3.o
|
||||
lib-$(CONFIG_SPARC32) += copy_user.o locks.o
|
||||
lib-$(CONFIG_SPARC64) += atomic_64.o
|
||||
|
|
|
|||
|
|
@ -33,9 +33,6 @@ EXPORT_SYMBOL(memset);
|
|||
EXPORT_SYMBOL(memmove);
|
||||
EXPORT_SYMBOL(__bzero);
|
||||
|
||||
/* Moving data to/from/in userspace. */
|
||||
EXPORT_SYMBOL(__strncpy_from_user);
|
||||
|
||||
/* Networking helper routines. */
|
||||
EXPORT_SYMBOL(csum_partial);
|
||||
|
||||
|
|
|
|||
|
|
@ -1,47 +0,0 @@
|
|||
/* strncpy_from_user.S: Sparc strncpy from userspace.
|
||||
*
|
||||
* Copyright(C) 1996 David S. Miller
|
||||
*/
|
||||
|
||||
#include <linux/linkage.h>
|
||||
#include <asm/ptrace.h>
|
||||
#include <asm/errno.h>
|
||||
|
||||
.text
|
||||
|
||||
/* Must return:
|
||||
*
|
||||
* -EFAULT for an exception
|
||||
* count if we hit the buffer limit
|
||||
* bytes copied if we hit a null byte
|
||||
*/
|
||||
|
||||
ENTRY(__strncpy_from_user)
|
||||
/* %o0=dest, %o1=src, %o2=count */
|
||||
mov %o2, %o3
|
||||
1:
|
||||
subcc %o2, 1, %o2
|
||||
bneg 2f
|
||||
nop
|
||||
10:
|
||||
ldub [%o1], %o4
|
||||
add %o0, 1, %o0
|
||||
cmp %o4, 0
|
||||
add %o1, 1, %o1
|
||||
bne 1b
|
||||
stb %o4, [%o0 - 1]
|
||||
2:
|
||||
add %o2, 1, %o0
|
||||
retl
|
||||
sub %o3, %o0, %o0
|
||||
ENDPROC(__strncpy_from_user)
|
||||
|
||||
.section .fixup,#alloc,#execinstr
|
||||
.align 4
|
||||
4:
|
||||
retl
|
||||
mov -EFAULT, %o0
|
||||
|
||||
.section __ex_table,#alloc
|
||||
.align 4
|
||||
.word 10b, 4b
|
||||
|
|
@ -1,133 +0,0 @@
|
|||
/*
|
||||
* strncpy_from_user.S: Sparc64 strncpy from userspace.
|
||||
*
|
||||
* Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
|
||||
*/
|
||||
|
||||
#include <linux/linkage.h>
|
||||
#include <asm/asi.h>
|
||||
#include <asm/errno.h>
|
||||
|
||||
.data
|
||||
.align 8
|
||||
0: .xword 0x0101010101010101
|
||||
|
||||
.text
|
||||
|
||||
/* Must return:
|
||||
*
|
||||
* -EFAULT for an exception
|
||||
* count if we hit the buffer limit
|
||||
* bytes copied if we hit a null byte
|
||||
* (without the null byte)
|
||||
*
|
||||
* This implementation assumes:
|
||||
* %o1 is 8 aligned => !(%o2 & 7)
|
||||
* %o0 is 8 aligned (if not, it will be slooooow, but will work)
|
||||
*
|
||||
* This is optimized for the common case:
|
||||
* in my stats, 90% of src are 8 aligned (even on sparc32)
|
||||
* and average length is 18 or so.
|
||||
*/
|
||||
|
||||
ENTRY(__strncpy_from_user)
|
||||
/* %o0=dest, %o1=src, %o2=count */
|
||||
andcc %o1, 7, %g0 ! IEU1 Group
|
||||
bne,pn %icc, 30f ! CTI
|
||||
add %o0, %o2, %g3 ! IEU0
|
||||
60: ldxa [%o1] %asi, %g1 ! Load Group
|
||||
brlez,pn %o2, 10f ! CTI
|
||||
mov %o0, %o3 ! IEU0
|
||||
50: sethi %hi(0b), %o4 ! IEU0 Group
|
||||
ldx [%o4 + %lo(0b)], %o4 ! Load
|
||||
sllx %o4, 7, %o5 ! IEU1 Group
|
||||
1: sub %g1, %o4, %g2 ! IEU0 Group
|
||||
stx %g1, [%o0] ! Store
|
||||
add %o0, 8, %o0 ! IEU1
|
||||
andcc %g2, %o5, %g0 ! IEU1 Group
|
||||
bne,pn %xcc, 5f ! CTI
|
||||
add %o1, 8, %o1 ! IEU0
|
||||
cmp %o0, %g3 ! IEU1 Group
|
||||
bl,a,pt %xcc, 1b ! CTI
|
||||
61: ldxa [%o1] %asi, %g1 ! Load
|
||||
10: retl ! CTI Group
|
||||
mov %o2, %o0 ! IEU0
|
||||
5: srlx %g2, 32, %g7 ! IEU0 Group
|
||||
sethi %hi(0xff00), %o4 ! IEU1
|
||||
andcc %g7, %o5, %g0 ! IEU1 Group
|
||||
be,pn %icc, 2f ! CTI
|
||||
or %o4, %lo(0xff00), %o4 ! IEU0
|
||||
srlx %g1, 48, %g7 ! IEU0 Group
|
||||
andcc %g7, %o4, %g0 ! IEU1 Group
|
||||
be,pn %icc, 50f ! CTI
|
||||
andcc %g7, 0xff, %g0 ! IEU1 Group
|
||||
be,pn %icc, 51f ! CTI
|
||||
srlx %g1, 32, %g7 ! IEU0
|
||||
andcc %g7, %o4, %g0 ! IEU1 Group
|
||||
be,pn %icc, 52f ! CTI
|
||||
andcc %g7, 0xff, %g0 ! IEU1 Group
|
||||
be,pn %icc, 53f ! CTI
|
||||
2: andcc %g2, %o5, %g0 ! IEU1 Group
|
||||
be,pn %icc, 2f ! CTI
|
||||
srl %g1, 16, %g7 ! IEU0
|
||||
andcc %g7, %o4, %g0 ! IEU1 Group
|
||||
be,pn %icc, 54f ! CTI
|
||||
andcc %g7, 0xff, %g0 ! IEU1 Group
|
||||
be,pn %icc, 55f ! CTI
|
||||
andcc %g1, %o4, %g0 ! IEU1 Group
|
||||
be,pn %icc, 56f ! CTI
|
||||
andcc %g1, 0xff, %g0 ! IEU1 Group
|
||||
be,a,pn %icc, 57f ! CTI
|
||||
sub %o0, %o3, %o0 ! IEU0
|
||||
2: cmp %o0, %g3 ! IEU1 Group
|
||||
bl,a,pt %xcc, 50b ! CTI
|
||||
62: ldxa [%o1] %asi, %g1 ! Load
|
||||
retl ! CTI Group
|
||||
mov %o2, %o0 ! IEU0
|
||||
50: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 8, %o0
|
||||
51: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 7, %o0
|
||||
52: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 6, %o0
|
||||
53: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 5, %o0
|
||||
54: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 4, %o0
|
||||
55: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 3, %o0
|
||||
56: sub %o0, %o3, %o0
|
||||
retl
|
||||
sub %o0, 2, %o0
|
||||
57: retl
|
||||
sub %o0, 1, %o0
|
||||
30: brlez,pn %o2, 3f
|
||||
sub %g0, %o2, %o3
|
||||
add %o0, %o2, %o0
|
||||
63: lduba [%o1] %asi, %o4
|
||||
1: add %o1, 1, %o1
|
||||
brz,pn %o4, 2f
|
||||
stb %o4, [%o0 + %o3]
|
||||
addcc %o3, 1, %o3
|
||||
bne,pt %xcc, 1b
|
||||
64: lduba [%o1] %asi, %o4
|
||||
3: retl
|
||||
mov %o2, %o0
|
||||
2: retl
|
||||
add %o2, %o3, %o0
|
||||
ENDPROC(__strncpy_from_user)
|
||||
|
||||
.section __ex_table,"a"
|
||||
.align 4
|
||||
.word 60b, __retl_efault
|
||||
.word 61b, __retl_efault
|
||||
.word 62b, __retl_efault
|
||||
.word 63b, __retl_efault
|
||||
.word 64b, __retl_efault
|
||||
.previous
|
||||
|
|
@ -1,4 +1,6 @@
|
|||
#include <linux/module.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/errno.h>
|
||||
#include <linux/bug.h>
|
||||
|
||||
void copy_from_user_overflow(void)
|
||||
|
|
@ -6,3 +8,133 @@ void copy_from_user_overflow(void)
|
|||
WARN(1, "Buffer overflow detected!\n");
|
||||
}
|
||||
EXPORT_SYMBOL(copy_from_user_overflow);
|
||||
|
||||
#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
|
||||
|
||||
/* Return the high bit set in the first byte that is a zero */
|
||||
static inline unsigned long has_zero(unsigned long a)
|
||||
{
|
||||
return ((a - REPEAT_BYTE(0x01)) & ~a) & REPEAT_BYTE(0x80);
|
||||
}
|
||||
|
||||
static inline long find_zero(unsigned long c)
|
||||
{
|
||||
#ifdef CONFIG_64BIT
|
||||
if (!(c & 0xff00000000000000UL))
|
||||
return 0;
|
||||
if (!(c & 0x00ff000000000000UL))
|
||||
return 1;
|
||||
if (!(c & 0x0000ff0000000000UL))
|
||||
return 2;
|
||||
if (!(c & 0x000000ff00000000UL))
|
||||
return 3;
|
||||
#define __OFF 4
|
||||
#else
|
||||
#define __OFF 0
|
||||
#endif
|
||||
if (!(c & 0xff000000))
|
||||
return __OFF + 0;
|
||||
if (!(c & 0x00ff0000))
|
||||
return __OFF + 1;
|
||||
if (!(c & 0x0000ff00))
|
||||
return __OFF + 2;
|
||||
return __OFF + 3;
|
||||
#undef __OFF
|
||||
}
|
||||
|
||||
/*
|
||||
* Do a strncpy, return length of string without final '\0'.
|
||||
* 'count' is the user-supplied count (return 'count' if we
|
||||
* hit it), 'max' is the address space maximum (and we return
|
||||
* -EFAULT if we hit it).
|
||||
*/
|
||||
static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
|
||||
{
|
||||
long res = 0;
|
||||
|
||||
/*
|
||||
* Truncate 'max' to the user-specified limit, so that
|
||||
* we only have one limit we need to check in the loop
|
||||
*/
|
||||
if (max > count)
|
||||
max = count;
|
||||
|
||||
if (((long) dst | (long) src) & (sizeof(long) - 1))
|
||||
goto byte_at_a_time;
|
||||
|
||||
while (max >= sizeof(unsigned long)) {
|
||||
unsigned long c;
|
||||
|
||||
/* Fall back to byte-at-a-time if we get a page fault */
|
||||
if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
|
||||
break;
|
||||
*(unsigned long *)(dst+res) = c;
|
||||
if (has_zero(c))
|
||||
return res + find_zero(c);
|
||||
res += sizeof(unsigned long);
|
||||
max -= sizeof(unsigned long);
|
||||
}
|
||||
|
||||
byte_at_a_time:
|
||||
while (max) {
|
||||
char c;
|
||||
|
||||
if (unlikely(__get_user(c,src+res)))
|
||||
return -EFAULT;
|
||||
dst[res] = c;
|
||||
if (!c)
|
||||
return res;
|
||||
res++;
|
||||
max--;
|
||||
}
|
||||
|
||||
/*
|
||||
* Uhhuh. We hit 'max'. But was that the user-specified maximum
|
||||
* too? If so, that's ok - we got as much as the user asked for.
|
||||
*/
|
||||
if (res >= count)
|
||||
return res;
|
||||
|
||||
/*
|
||||
* Nope: we hit the address space limit, and we still had more
|
||||
* characters the caller would have wanted. That's an EFAULT.
|
||||
*/
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
/**
|
||||
* strncpy_from_user: - Copy a NUL terminated string from userspace.
|
||||
* @dst: Destination address, in kernel space. This buffer must be at
|
||||
* least @count bytes long.
|
||||
* @src: Source address, in user space.
|
||||
* @count: Maximum number of bytes to copy, including the trailing NUL.
|
||||
*
|
||||
* Copies a NUL-terminated string from userspace to kernel space.
|
||||
*
|
||||
* On success, returns the length of the string (not including the trailing
|
||||
* NUL).
|
||||
*
|
||||
* If access to userspace fails, returns -EFAULT (some data may have been
|
||||
* copied).
|
||||
*
|
||||
* If @count is smaller than the length of the string, copies @count bytes
|
||||
* and returns @count.
|
||||
*/
|
||||
long strncpy_from_user(char *dst, const char __user *src, long count)
|
||||
{
|
||||
unsigned long max_addr, src_addr;
|
||||
|
||||
if (unlikely(count <= 0))
|
||||
return 0;
|
||||
|
||||
max_addr = ~0UL;
|
||||
if (likely(segment_eq(get_fs(), USER_DS)))
|
||||
max_addr = STACK_TOP;
|
||||
src_addr = (unsigned long)src;
|
||||
if (likely(src_addr < max_addr)) {
|
||||
unsigned long max = max_addr - src_addr;
|
||||
return do_strncpy_from_user(dst, src, count, max);
|
||||
}
|
||||
return -EFAULT;
|
||||
}
|
||||
EXPORT_SYMBOL(strncpy_from_user);
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue