commit 3b825735d8ad2645bafac8269e4078349dc1d949
parent 066a0306a1e6b4bc92dac585fbf340db3ee92cb5
Author: FRIGN <dev@frign.de>
Date: Tue, 10 Mar 2015 21:16:21 +0100
Implement reallocarray()
Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
later.
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].
A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)
This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).
[0]: http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man3/calloc.3
Diffstat:
14 files changed, 84 insertions(+), 27 deletions(-)
diff --git a/Makefile b/Makefile
@@ -57,6 +57,7 @@ LIBUTILSRC =\
libutil/md5.c\
libutil/mode.c\
libutil/putword.c\
+ libutil/reallocarray.c\
libutil/recurse.c\
libutil/rm.c\
libutil/sha1.c\
diff --git a/col.c b/col.c
@@ -177,7 +177,7 @@ allocbuf(void)
{
char **bp;
- buff = emalloc(sizeof(*buff) * pagsize);
+ buff = ereallocarray(buff, pagsize, sizeof(*buff));
for (bp = buff; bp < &buff[pagsize]; ++bp)
*bp = emalloc(NCOLS);
}
diff --git a/cut.c b/cut.c
@@ -56,7 +56,7 @@ parselist(char *str)
if (*s == ',')
n++;
}
- r = emalloc(n * sizeof(Range));
+ r = ereallocarray(r, n, sizeof(*r));
for (s = str; n; n--, s++) {
r->min = (*s == '-') ? 1 : strtoul(s, &s, 10);
r->max = (*s == '-') ? strtoul(s + 1, &s, 10) : r->min;
diff --git a/expand.c b/expand.c
@@ -19,12 +19,12 @@ parselist(const char *s)
for (i = 0; (p = strsep(&tmp, " ,")); i++) {
if (*p == '\0')
eprintf("empty field in tablist\n");
- tablist = erealloc(tablist, (i + 1) * sizeof(*tablist));
+ tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
tablist[i] = estrtonum(p, 1, MIN(LLONG_MAX, SIZE_MAX));
if (i > 0 && tablist[i - 1] >= tablist[i])
eprintf("tablist must be ascending\n");
}
- tablist = erealloc(tablist, (i + 1) * sizeof(*tablist));
+ tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
/* tab length = 1 for the overflowing case later in the matcher */
tablist[i] = 1;
return i;
diff --git a/find.c b/find.c
@@ -380,7 +380,7 @@ pri_exec(Arg *arg)
/* if we have too many files, realloc (with space for NULL termination) */
if (e->u.p.next + 1 == e->u.p.cap)
- e->argv = erealloc(e->argv, (e->u.p.cap *= 2) * sizeof(*e->argv));
+ e->argv = ereallocarray(e->argv, e->u.p.cap *= 2, sizeof(*e->argv));
e->argv[e->u.p.next++] = estrdup(arg->path);
e->u.p.filelen += len + sizeof(arg->path);
@@ -595,7 +595,7 @@ get_exec_arg(char *argv[], Extra *extra)
e->u.p.arglen = e->u.p.filelen = 0;
e->u.p.first = e->u.p.next = arg - argv - 1;
e->u.p.cap = (arg - argv) * 2;
- e->argv = emalloc(e->u.p.cap * sizeof(*e->argv));
+ e->argv = ereallocarray(e->argv, e->u.p.cap, sizeof(*e->argv));
for (arg = argv, new = e->argv; *arg; arg++, new++) {
*new = *arg;
@@ -604,7 +604,7 @@ get_exec_arg(char *argv[], Extra *extra)
arg++; /* due to our extra NULL */
} else {
e->argv = argv;
- e->u.s.braces = emalloc(++nbraces * sizeof(*e->u.s.braces)); /* ++ for NULL */
+ e->u.s.braces = ereallocarray(e->u.s.braces, ++nbraces, sizeof(*e->u.s.braces)); /* ++ for NULL */
for (arg = argv, braces = e->u.s.braces; *arg; arg++)
if (!strcmp(*arg, "{}"))
@@ -632,7 +632,7 @@ get_ok_arg(char *argv[], Extra *extra)
*arg = NULL;
o->argv = argv;
- o->braces = emalloc(++nbraces * sizeof(*o->braces));
+ o->braces = ereallocarray(o->braces, ++nbraces, sizeof(*o->braces));
for (arg = argv, braces = o->braces; *arg; arg++)
if (!strcmp(*arg, "{}"))
@@ -824,7 +824,7 @@ parse(int argc, char **argv)
* https://en.wikipedia.org/wiki/Shunting-yard_algorithm
* read from infix, resulting rpn ends up in rpn, next position in rpn is out
* push operators onto stack, next position in stack is top */
- rpn = emalloc((ntok + gflags.print) * sizeof(*rpn));
+ rpn = ereallocarray(rpn, ntok + gflags.print, sizeof(*rpn));
for (tok = infix, out = rpn, top = stack; tok->type != END; tok++) {
switch (tok->type) {
case PRIM: *out++ = *tok; break;
diff --git a/libutil/reallocarray.c b/libutil/reallocarray.c
@@ -0,0 +1,51 @@
+/* $OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt Exp $ */
+/*
+ * Copyright (c) 2008 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 <sys/types.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "../util.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 (1UL << (sizeof(size_t) * 4))
+
+void *
+reallocarray(void *optr, size_t nmemb, size_t size)
+{
+ if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+ nmemb > 0 && SIZE_MAX / nmemb < size) {
+ errno = ENOMEM;
+ return NULL;
+ }
+ return realloc(optr, size * nmemb);
+}
+
+void *
+ereallocarray(void *optr, size_t nmemb, size_t size)
+{
+ void *p;
+
+ if (!(p = reallocarray(optr, nmemb, size)))
+ eprintf("reallocarray: out of memory\n");
+
+ return p;
+}
diff --git a/ls.c b/ls.c
@@ -217,7 +217,7 @@ lsdir(const char *path)
mkent(&ent, d->d_name, Fflag || lflag || pflag || iflag || Rflag, Lflag);
ls(&ent, Rflag);
} else {
- ents = erealloc(ents, ++n * sizeof(*ents));
+ ents = ereallocarray(ents, ++n, sizeof(*ents));
name = p = estrdup(d->d_name);
if (qflag) {
q = d->d_name;
@@ -269,7 +269,7 @@ usage(void)
int
main(int argc, char *argv[])
{
- struct entry *ents;
+ struct entry *ents = NULL;
size_t i;
ARGBEGIN {
@@ -341,7 +341,7 @@ main(int argc, char *argv[])
if (argc == 0)
*--argv = ".", argc++;
- ents = emalloc(argc * sizeof(*ents));
+ ents = ereallocarray(ents, argc, sizeof(*ents));
for (i = 0; i < argc; i++)
mkent(&ents[i], argv[i], 1, Hflag || Lflag);
diff --git a/paste.c b/paste.c
@@ -85,8 +85,8 @@ usage(void)
int
main(int argc, char *argv[])
{
- struct fdescr *dsc;
- Rune *delim;
+ struct fdescr *dsc = NULL;
+ Rune *delim = NULL;
size_t i, len;
int seq = 0;
char *adelim = "\t";
@@ -107,11 +107,11 @@ main(int argc, char *argv[])
/* populate delimiters */
unescape(adelim);
- delim = emalloc((utflen(adelim) + 1) * sizeof(*delim));
+ delim = ereallocarray(delim, utflen(adelim) + 1, sizeof(*delim));
len = utftorunestr(adelim, delim);
/* populate file list */
- dsc = emalloc(argc * sizeof(*dsc));
+ dsc = ereallocarray(dsc, argc, sizeof(*dsc));
for (i = 0; i < argc; i++) {
if (strcmp(argv[i], "-") == 0)
diff --git a/printf.c b/printf.c
@@ -111,7 +111,7 @@ main(int argc, char *argv[])
break;
case 'c':
unescape(arg);
- rarg = emalloc((utflen(arg) + 1) * sizeof(*rarg));
+ rarg = ereallocarray(rarg, utflen(arg) + 1, sizeof(*rarg));
utftorunestr(arg, rarg);
efputrune(rarg, stdout, "<stdout>");
free(rarg);
@@ -125,7 +125,7 @@ main(int argc, char *argv[])
if (arg[j] == '\'' || arg[j] == '\"') {
arg += j + 1;
unescape(arg);
- rarg = emalloc((utflen(arg) + 1) * sizeof(*rarg));
+ rarg = ereallocarray(rarg, utflen(arg) + 1, sizeof(*rarg));
utftorunestr(arg, rarg);
num = rarg[0];
} else
diff --git a/sed.c b/sed.c
@@ -275,7 +275,7 @@ resize(void **ptr, size_t *nmemb, size_t size, size_t new_nmemb, void **next)
void *n, *tmp;
if (new_nmemb) {
- tmp = erealloc(*ptr, new_nmemb * size);
+ tmp = ereallocarray(*ptr, new_nmemb, size);
} else { /* turns out realloc(*ptr, 0) != free(*ptr) */
free(*ptr);
tmp = NULL;
@@ -596,7 +596,10 @@ chompr(char *s, Rune rune)
Rune *
strtorunes(char *s, size_t nrunes)
{
- Rune *rs = emalloc(sizeof(*rs) * nrunes + 1), *rp = rs;
+ Rune *rs = NULL, *rp;
+
+ rs = ereallocarray(rs, nrunes + 1, sizeof(*rs));
+ rp = rs;
while (nrunes--)
s += chartorune(rp++, s);
diff --git a/strings.c b/strings.c
@@ -11,11 +11,11 @@ static char *format = "";
static void
strings(FILE *fp, const char *fname, size_t len)
{
- Rune r, *rbuf;
+ Rune r, *rbuf = NULL;
size_t i, bread;
off_t off;
- rbuf = emalloc(len * sizeof(*rbuf));
+ rbuf = ereallocarray(rbuf, len, sizeof(*rbuf));
for (off = 0, i = 0; (bread = efgetrune(&r, fp, fname)); ) {
off += bread;
diff --git a/tr.c b/tr.c
@@ -71,16 +71,16 @@ rstrmatch(Rune *r, char *s, size_t n)
static size_t
makeset(char *str, struct range **set, int (**check)(Rune))
{
- Rune *rstr;
+ Rune *rstr = NULL;
size_t len, i, j, m, n;
size_t q, setranges = 0;
int factor, base;
/* rstr defines at most len ranges */
unescape(str);
- rstr = emalloc((utflen(str) + 1) * sizeof(*rstr));
+ rstr = ereallocarray(rstr, utflen(str) + 1, sizeof(*rstr));
len = utftorunestr(str, rstr);
- *set = emalloc(len * sizeof(**set));
+ *set = ereallocarray(*set, len, sizeof(**set));
for (i = 0; i < len; i++) {
if (rstr[i] == '[') {
diff --git a/unexpand.c b/unexpand.c
@@ -19,12 +19,12 @@ parselist(const char *s)
for (i = 0; (p = strsep(&tmp, " ,")); i++) {
if (*p == '\0')
eprintf("empty field in tablist\n");
- tablist = erealloc(tablist, (i + 1) * sizeof(*tablist));
+ tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
tablist[i] = estrtonum(p, 1, MIN(LLONG_MAX, SIZE_MAX));
if (i > 0 && tablist[i - 1] >= tablist[i])
eprintf("tablist must be ascending\n");
}
- tablist = erealloc(tablist, (i + 1) * sizeof(*tablist));
+ tablist = ereallocarray(tablist, i + 1, sizeof(*tablist));
return i;
}
diff --git a/util.h b/util.h
@@ -26,6 +26,8 @@ void apathmax(char **, size_t *);
void *ecalloc(size_t, size_t);
void *emalloc(size_t);
void *erealloc(void *, size_t);
+void *reallocarray(void *, size_t, size_t);
+void *ereallocarray(void *, size_t, size_t);
char *estrdup(const char *);
char *estrndup(const char *, size_t);
void *encalloc(int, size_t, size_t);
