mirror of
https://gitlab.freedesktop.org/libbsd/libbsd.git
synced 2025-01-07 09:48:12 +01:00
Add recallocarray() and freezero() from OpenBSD
Add recallocarray(), introduced in OpenBSD 6.1, and freezero(), introduced in OpenBSD 6.2. The former is imported as-is from OpenBSD, while the latter is the non-malloc-internal branch of the same code (and also the OpenSSH portable variant). Both of these originated in OpenBSD, but have also been implemented by IllumOS, cf. https://www.illumos.org/issues/8546 Documentation for these functions is in malloc(3) upstream, the relevant parts of which were previously imported in reallocarray(3bsd). Update reallocarray(3bsd) with the changes that were introduced since, and add the relevant bits for recallocarray() and freezero(), plus aliases. [guillem@hadrons.org: Update copyright in COPYING. ] Closes: !10 Signed-off-by: Guillem Jover <guillem@hadrons.org>
This commit is contained in:
Faidon Liambotis
Guillem Jover
parent
9c85d828a1
commit
01f0d1ea1e
4
COPYING
4
COPYING
@ -368,6 +368,7 @@ Files:
|
||||
src/arc4random_unix.h
|
||||
src/arc4random_win.h
|
||||
src/closefrom.c
|
||||
src/freezero.c
|
||||
src/getentropy_aix.c
|
||||
src/getentropy_bsd.c
|
||||
src/getentropy_hpux.c
|
||||
@ -378,6 +379,7 @@ Files:
|
||||
src/getentropy_win.c
|
||||
src/readpassphrase.c
|
||||
src/reallocarray.c
|
||||
src/recallocarray.c
|
||||
src/strlcat.c
|
||||
src/strlcpy.c
|
||||
Copyright:
|
||||
@ -389,7 +391,7 @@ Copyright:
|
||||
Todd C. Miller <Todd.Miller@courtesan.com>
|
||||
Copyright © 2004 Ted Unangst
|
||||
Copyright © 2008 Damien Miller <djm@openbsd.org>
|
||||
Copyright © 2008 Otto Moerbeek <otto@drijf.net>
|
||||
Copyright © 2008, 2010-2011, 2016-2017 Otto Moerbeek <otto@drijf.net>
|
||||
Copyright © 2013 Markus Friedl <markus@openbsd.org>
|
||||
Copyright © 2014 Bob Beck <beck@obtuse.com>
|
||||
Copyright © 2014 Brent Cook <bcook@openbsd.org>
|
||||
|
||||
@ -75,6 +75,8 @@ void *reallocf(void *ptr, size_t size);
|
||||
(defined(__GLIBC__) && (!__GLIBC_PREREQ(2, 26) || !defined(_GNU_SOURCE)))
|
||||
void *reallocarray(void *ptr, size_t nmemb, size_t size);
|
||||
#endif
|
||||
void *recallocarray(void *ptr, size_t oldnmemb, size_t nmemb, size_t size);
|
||||
void freezero(void *ptr, size_t size);
|
||||
|
||||
long long strtonum(const char *nptr, long long minval, long long maxval,
|
||||
const char **errstr);
|
||||
|
||||
@ -165,6 +165,7 @@ dist_man_MANS = \
|
||||
fgetln.3bsd \
|
||||
fgetwln.3bsd \
|
||||
flopen.3bsd \
|
||||
freezero.3bsd \
|
||||
fmtcheck.3bsd \
|
||||
fparseln.3bsd \
|
||||
fpurge.3bsd \
|
||||
@ -195,6 +196,7 @@ dist_man_MANS = \
|
||||
readpassphrase.3bsd \
|
||||
reallocarray.3bsd \
|
||||
reallocf.3bsd \
|
||||
recallocarray.3bsd \
|
||||
setmode.3bsd \
|
||||
setproctitle.3bsd \
|
||||
setproctitle_init.3bsd \
|
||||
|
||||
1
man/freezero.3bsd
Normal file
1
man/freezero.3bsd
Normal file
@ -0,0 +1 @@
|
||||
.so man3/reallocarray.3bsd
|
||||
@ -30,13 +30,15 @@
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
.\" SUCH DAMAGE.
|
||||
.\"
|
||||
.\" $OpenBSD: malloc.3,v 1.78 2014/05/01 18:41:59 jmc Exp $
|
||||
.\" $OpenBSD: malloc.3,v 1.126 2019/09/14 13:16:50 otto Exp $
|
||||
.\"
|
||||
.Dd $Mdocdate: May 1 2014 $
|
||||
.Dd $Mdocdate: September 14 2019 $
|
||||
.Dt REALLOCARRAY 3bsd
|
||||
.Os
|
||||
.Sh NAME
|
||||
.Nm reallocarray
|
||||
.Nm reallocarray ,
|
||||
.Nm recallocarray ,
|
||||
.Nm freezero
|
||||
.Nd memory allocation and deallocation
|
||||
.Sh LIBRARY
|
||||
.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
|
||||
@ -49,59 +51,245 @@
|
||||
for include usage.)
|
||||
.Ft void *
|
||||
.Fn reallocarray "void *ptr" "size_t nmemb" "size_t size"
|
||||
.Ft void *
|
||||
.Fn recallocarray "void *ptr" "size_t oldnmemb" "size_t nmemb" "size_t size"
|
||||
.Ft void
|
||||
.Fn freezero "void *ptr" "size_t size"
|
||||
.Sh DESCRIPTION
|
||||
.Pp
|
||||
When using
|
||||
.Fn malloc
|
||||
be careful to avoid the following idiom:
|
||||
.Bd -literal -offset indent
|
||||
if ((p = malloc(num * size)) == NULL)
|
||||
err(1, "malloc");
|
||||
.Ed
|
||||
.Pp
|
||||
The multiplication may lead to an integer overflow, which can
|
||||
be avoided using the extension
|
||||
.Fn reallocarray ,
|
||||
as follows:
|
||||
.Bd -literal -offset indent
|
||||
if ((p = reallocarray(NULL, num, size)) == NULL)
|
||||
err(1, "malloc");
|
||||
.Ed
|
||||
.Pp
|
||||
Alternatively
|
||||
.Fn calloc
|
||||
is a more portable solution which comes with the cost of clearing memory.
|
||||
.Pp
|
||||
If
|
||||
.Fn malloc
|
||||
must be used, be sure to test for overflow:
|
||||
.Bd -literal -offset indent
|
||||
if (size && num > SIZE_MAX / size) {
|
||||
errno = ENOMEM;
|
||||
err(1, "overflow");
|
||||
}
|
||||
.Ed
|
||||
.Pp
|
||||
The use of
|
||||
Designed for safe allocation of arrays,
|
||||
the
|
||||
.Fn reallocarray
|
||||
or
|
||||
.Fn calloc
|
||||
is strongly encouraged when allocating multiple sized objects
|
||||
in order to avoid possible integer overflows.
|
||||
function is similar to
|
||||
.Fn realloc
|
||||
except it operates on
|
||||
.Fa nmemb
|
||||
members of size
|
||||
.Fa size
|
||||
and checks for integer overflow in the calculation
|
||||
.Fa nmemb
|
||||
*
|
||||
.Fa size .
|
||||
.Pp
|
||||
Used for the allocation of memory holding sensitive data,
|
||||
the
|
||||
.Fn recallocarray
|
||||
function guarantees that memory becoming unallocated is explicitly
|
||||
.Em discarded ,
|
||||
meaning cached free objects are cleared with
|
||||
.Xr explicit_bzero 3 .
|
||||
.Pp
|
||||
The
|
||||
.Fn recallocarray
|
||||
function is similar to
|
||||
.Fn reallocarray
|
||||
except it ensures newly allocated memory is cleared similar to
|
||||
.Fn calloc .
|
||||
If
|
||||
.Fa ptr
|
||||
is
|
||||
.Dv NULL ,
|
||||
.Fa oldnmemb
|
||||
is ignored and the call is equivalent to
|
||||
.Fn calloc .
|
||||
If
|
||||
.Fa ptr
|
||||
is not
|
||||
.Dv NULL ,
|
||||
.Fa oldnmemb
|
||||
must be a value such that
|
||||
.Fa oldnmemb
|
||||
*
|
||||
.Fa size
|
||||
is the size of the earlier allocation that returned
|
||||
.Fa ptr ,
|
||||
otherwise the behavior is undefined.
|
||||
The
|
||||
.Fn freezero
|
||||
function is similar to the
|
||||
.Fn free
|
||||
function except it ensures memory is explicitly discarded.
|
||||
If
|
||||
.Fa ptr
|
||||
is
|
||||
.Dv NULL ,
|
||||
no action occurs.
|
||||
If
|
||||
.Fa ptr
|
||||
is not
|
||||
.Dv NULL ,
|
||||
the
|
||||
.Fa size
|
||||
argument must be equal to or smaller than the size of the earlier allocation
|
||||
that returned
|
||||
.Fa ptr .
|
||||
.Fn freezero
|
||||
guarantees the memory range starting at
|
||||
.Fa ptr
|
||||
with length
|
||||
.Fa size
|
||||
is discarded while deallocating the whole object originally allocated.
|
||||
.Sh RETURN VALUES
|
||||
The
|
||||
.Fn reallocarray
|
||||
function returns a pointer to the allocated space if successful; otherwise,
|
||||
and
|
||||
.Fn recallocarray
|
||||
functions return a pointer to the allocated space if successful; otherwise,
|
||||
a null pointer is returned and
|
||||
.Va errno
|
||||
is set to
|
||||
.Er ENOMEM .
|
||||
.Pp
|
||||
If multiplying
|
||||
.Fa nmemb
|
||||
and
|
||||
.Fa size
|
||||
results in integer overflow,
|
||||
.Fn reallocarray
|
||||
and
|
||||
.Fn recallocarray
|
||||
return
|
||||
.Dv NULL
|
||||
and set
|
||||
.Va errno
|
||||
to
|
||||
.Er ENOMEM .
|
||||
.Pp
|
||||
If
|
||||
.Fa ptr
|
||||
is not
|
||||
.Dv NULL
|
||||
and multiplying
|
||||
.Fa oldnmemb
|
||||
and
|
||||
.Fa size
|
||||
results in integer overflow
|
||||
.Fn recallocarray
|
||||
returns
|
||||
.Dv NULL
|
||||
and sets
|
||||
.Va errno
|
||||
to
|
||||
.Er EINVAL .
|
||||
.Sh IDIOMS
|
||||
Consider
|
||||
.Fn calloc
|
||||
or the extensions
|
||||
.Fn reallocarray
|
||||
and
|
||||
.Fn recallocarray
|
||||
when there is multiplication in the
|
||||
.Fa size
|
||||
argument of
|
||||
.Fn malloc
|
||||
or
|
||||
.Fn realloc .
|
||||
For example, avoid this common idiom as it may lead to integer overflow:
|
||||
.Bd -literal -offset indent
|
||||
if ((p = malloc(num * size)) == NULL)
|
||||
err(1, NULL);
|
||||
.Ed
|
||||
.Pp
|
||||
A drop-in replacement is
|
||||
.Fn reallocarray :
|
||||
.Bd -literal -offset indent
|
||||
if ((p = reallocarray(NULL, num, size)) == NULL)
|
||||
err(1, NULL);
|
||||
.Ed
|
||||
.Pp
|
||||
Alternatively,
|
||||
.Fn calloc
|
||||
may be used at the cost of initialization overhead.
|
||||
.Pp
|
||||
When using
|
||||
.Fn realloc ,
|
||||
be careful to avoid the following idiom:
|
||||
.Bd -literal -offset indent
|
||||
size += 50;
|
||||
if ((p = realloc(p, size)) == NULL)
|
||||
return (NULL);
|
||||
.Ed
|
||||
.Pp
|
||||
Do not adjust the variable describing how much memory has been allocated
|
||||
until the allocation has been successful.
|
||||
This can cause aberrant program behavior if the incorrect size value is used.
|
||||
In most cases, the above sample will also result in a leak of memory.
|
||||
As stated earlier, a return value of
|
||||
.Dv NULL
|
||||
indicates that the old object still remains allocated.
|
||||
Better code looks like this:
|
||||
.Bd -literal -offset indent
|
||||
newsize = size + 50;
|
||||
if ((newp = realloc(p, newsize)) == NULL) {
|
||||
free(p);
|
||||
p = NULL;
|
||||
size = 0;
|
||||
return (NULL);
|
||||
}
|
||||
p = newp;
|
||||
size = newsize;
|
||||
.Ed
|
||||
.Pp
|
||||
As with
|
||||
.Fn malloc ,
|
||||
it is important to ensure the new size value will not overflow;
|
||||
i.e. avoid allocations like the following:
|
||||
.Bd -literal -offset indent
|
||||
if ((newp = realloc(p, num * size)) == NULL) {
|
||||
...
|
||||
.Ed
|
||||
.Pp
|
||||
Instead, use
|
||||
.Fn reallocarray :
|
||||
.Bd -literal -offset indent
|
||||
if ((newp = reallocarray(p, num, size)) == NULL) {
|
||||
...
|
||||
.Ed
|
||||
.Pp
|
||||
Calling
|
||||
.Fn realloc
|
||||
with a
|
||||
.Dv NULL
|
||||
.Fa ptr
|
||||
is equivalent to calling
|
||||
.Fn malloc .
|
||||
Instead of this idiom:
|
||||
.Bd -literal -offset indent
|
||||
if (p == NULL)
|
||||
newp = malloc(newsize);
|
||||
else
|
||||
newp = realloc(p, newsize);
|
||||
.Ed
|
||||
.Pp
|
||||
Use the following:
|
||||
.Bd -literal -offset indent
|
||||
newp = realloc(p, newsize);
|
||||
.Ed
|
||||
.Pp
|
||||
The
|
||||
.Fn recallocarray
|
||||
function should be used for resizing objects containing sensitive data like
|
||||
keys.
|
||||
To avoid leaking information,
|
||||
it guarantees memory is cleared before placing it on the internal free list.
|
||||
Deallocation of such an object should be done by calling
|
||||
.Fn freezero .
|
||||
|
||||
.Sh SEE ALSO
|
||||
.Xr malloc 3 ,
|
||||
.Xr calloc 3 ,
|
||||
.Xr alloca 3
|
||||
.Sh HISTORY
|
||||
The
|
||||
.Fn reallocarray
|
||||
appeared in
|
||||
function appeared in
|
||||
.Ox 5.6 ,
|
||||
glibc 2.26.
|
||||
and glibc 2.26.
|
||||
The
|
||||
.Fn recallocarray
|
||||
function appeared in
|
||||
.Ox 6.1 .
|
||||
The
|
||||
.Fn freezero
|
||||
function appeared in
|
||||
.Ox 6.2 .
|
||||
|
||||
1
man/recallocarray.3bsd
Normal file
1
man/recallocarray.3bsd
Normal file
@ -0,0 +1 @@
|
||||
.so man3/reallocarray.3bsd
|
||||
@ -86,6 +86,7 @@ libbsd_la_SOURCES = \
|
||||
expand_number.c \
|
||||
explicit_bzero.c \
|
||||
fgetln.c \
|
||||
freezero.c \
|
||||
fgetwln.c \
|
||||
flopen.c \
|
||||
fmtcheck.c \
|
||||
@ -111,6 +112,7 @@ libbsd_la_SOURCES = \
|
||||
readpassphrase.c \
|
||||
reallocarray.c \
|
||||
reallocf.c \
|
||||
recallocarray.c \
|
||||
setmode.c \
|
||||
setproctitle.c \
|
||||
strlcat.c \
|
||||
|
||||
30
src/freezero.c
Normal file
30
src/freezero.c
Normal file
@ -0,0 +1,30 @@
|
||||
/* $OpenBSD: malloc.c,v 1.267 2020/11/23 15:42:11 otto Exp $ */
|
||||
/*
|
||||
* Copyright (c) 2008, 2010, 2011, 2016 Otto Moerbeek <otto@drijf.net>
|
||||
*
|
||||
* Permission to use, copy, modify, and distribute this software for any
|
||||
* purpose with or without fee is hereby granted, provided that the above
|
||||
* copyright notice and this permission notice appear in all copies.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
||||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
||||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
||||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
||||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
||||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
||||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
|
||||
void
|
||||
freezero(void *ptr, size_t sz)
|
||||
{
|
||||
/* This is legal. */
|
||||
if (ptr == NULL)
|
||||
return;
|
||||
|
||||
explicit_bzero(ptr, sz);
|
||||
free(ptr);
|
||||
}
|
||||
@ -184,4 +184,7 @@ LIBBSD_0.10.0 {
|
||||
|
||||
LIBBSD_0.11.0 {
|
||||
strnvisx;
|
||||
|
||||
recallocarray;
|
||||
freezero;
|
||||
} LIBBSD_0.10.0;
|
||||
|
||||
80
src/recallocarray.c
Normal file
80
src/recallocarray.c
Normal file
@ -0,0 +1,80 @@
|
||||
/* $OpenBSD: recallocarray.c,v 1.1 2017/03/06 18:44:21 otto Exp $ */
|
||||
/*
|
||||
* Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net>
|
||||
*
|
||||
* Permission to use, copy, modify, and distribute this software for any
|
||||
* purpose with or without fee is hereby granted, provided that the above
|
||||
* copyright notice and this permission notice appear in all copies.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
||||
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
||||
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
||||
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
||||
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
||||
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
||||
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
*/
|
||||
|
||||
#include <errno.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdint.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
|
||||
/*
|
||||
* This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
|
||||
* if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
|
||||
*/
|
||||
#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
|
||||
|
||||
void *
|
||||
recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
|
||||
{
|
||||
size_t oldsize, newsize;
|
||||
void *newptr;
|
||||
|
||||
if (ptr == NULL)
|
||||
return calloc(newnmemb, size);
|
||||
|
||||
if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
|
||||
newnmemb > 0 && SIZE_MAX / newnmemb < size) {
|
||||
errno = ENOMEM;
|
||||
return NULL;
|
||||
}
|
||||
newsize = newnmemb * size;
|
||||
|
||||
if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
|
||||
oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
|
||||
errno = EINVAL;
|
||||
return NULL;
|
||||
}
|
||||
oldsize = oldnmemb * size;
|
||||
|
||||
/*
|
||||
* Don't bother too much if we're shrinking just a bit,
|
||||
* we do not shrink for series of small steps, oh well.
|
||||
*/
|
||||
if (newsize <= oldsize) {
|
||||
size_t d = oldsize - newsize;
|
||||
|
||||
if (d < oldsize / 2 && d < (size_t)getpagesize()) {
|
||||
memset((char *)ptr + newsize, 0, d);
|
||||
return ptr;
|
||||
}
|
||||
}
|
||||
|
||||
newptr = malloc(newsize);
|
||||
if (newptr == NULL)
|
||||
return NULL;
|
||||
|
||||
if (newsize > oldsize) {
|
||||
memcpy(newptr, ptr, oldsize);
|
||||
memset((char *)newptr + oldsize, 0, newsize - oldsize);
|
||||
} else
|
||||
memcpy(newptr, ptr, newsize);
|
||||
|
||||
explicit_bzero(ptr, oldsize);
|
||||
free(ptr);
|
||||
|
||||
return newptr;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user