linux-stable/scripts/kconfig/zconf.l
Masahiro Yamada 3f96ff44bb kconfig: fix memory leak when EOF is encountered in quotation
[ Upstream commit fbac5977d8 ]

An unterminated string literal followed by new line is passed to the
parser (with "multi-line strings not supported" warning shown), then
handled properly there.

On the other hand, an unterminated string literal at end of file is
never passed to the parser, then results in memory leak.

[Test Code]

  ----------(Kconfig begin)----------
  source "Kconfig.inc"

  config A
          bool "a"
  -----------(Kconfig end)-----------

  --------(Kconfig.inc begin)--------
  config B
          bool "b\No new line at end of file
  ---------(Kconfig.inc end)---------

[Summary from Valgrind]

  Before the fix:

    LEAK SUMMARY:
       definitely lost: 16 bytes in 1 blocks
       ...

  After the fix:

    LEAK SUMMARY:
       definitely lost: 0 bytes in 0 blocks
       ...

Eliminate the memory leak path by handling this case. Of course, such
a Kconfig file is wrong already, so I will add an error message later.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-26 09:37:04 +01:00

376 lines
6.9 KiB
Text

%option nostdinit noyywrap never-interactive full ecs
%option 8bit nodefault perf-report perf-report
%option noinput
%x COMMAND HELP STRING PARAM
%{
/*
* Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
* Released under the terms of the GNU GPL v2.0.
*/
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "lkc.h"
#define START_STRSIZE 16
static struct {
struct file *file;
int lineno;
} current_pos;
static char *text;
static int text_size, text_asize;
struct buffer {
struct buffer *parent;
YY_BUFFER_STATE state;
};
struct buffer *current_buf;
static int last_ts, first_ts;
static void zconf_endhelp(void);
static void zconf_endfile(void);
static void new_string(void)
{
text = xmalloc(START_STRSIZE);
text_asize = START_STRSIZE;
text_size = 0;
*text = 0;
}
static void append_string(const char *str, int size)
{
int new_size = text_size + size + 1;
if (new_size > text_asize) {
new_size += START_STRSIZE - 1;
new_size &= -START_STRSIZE;
text = realloc(text, new_size);
text_asize = new_size;
}
memcpy(text + text_size, str, size);
text_size += size;
text[text_size] = 0;
}
static void alloc_string(const char *str, int size)
{
text = xmalloc(size + 1);
memcpy(text, str, size);
text[size] = 0;
}
static void warn_ignored_character(char chr)
{
fprintf(stderr,
"%s:%d:warning: ignoring unsupported character '%c'\n",
current_file->name, yylineno, chr);
}
%}
n [A-Za-z0-9_-]
%%
int str = 0;
int ts, i;
[ \t]*#.*\n |
[ \t]*\n {
current_file->lineno++;
return T_EOL;
}
[ \t]*#.*
[ \t]+ {
BEGIN(COMMAND);
}
. {
unput(yytext[0]);
BEGIN(COMMAND);
}
<COMMAND>{
{n}+ {
const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
BEGIN(PARAM);
current_pos.file = current_file;
current_pos.lineno = current_file->lineno;
if (id && id->flags & TF_COMMAND) {
zconflval.id = id;
return id->token;
}
alloc_string(yytext, yyleng);
zconflval.string = text;
return T_WORD;
}
. warn_ignored_character(*yytext);
\n {
BEGIN(INITIAL);
current_file->lineno++;
return T_EOL;
}
}
<PARAM>{
"&&" return T_AND;
"||" return T_OR;
"(" return T_OPEN_PAREN;
")" return T_CLOSE_PAREN;
"!" return T_NOT;
"=" return T_EQUAL;
"!=" return T_UNEQUAL;
"<=" return T_LESS_EQUAL;
">=" return T_GREATER_EQUAL;
"<" return T_LESS;
">" return T_GREATER;
\"|\' {
str = yytext[0];
new_string();
BEGIN(STRING);
}
\n BEGIN(INITIAL); current_file->lineno++; return T_EOL;
({n}|[/.])+ {
const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
if (id && id->flags & TF_PARAM) {
zconflval.id = id;
return id->token;
}
alloc_string(yytext, yyleng);
zconflval.string = text;
return T_WORD;
}
#.* /* comment */
\\\n current_file->lineno++;
[[:blank:]]+
. warn_ignored_character(*yytext);
<<EOF>> {
BEGIN(INITIAL);
}
}
<STRING>{
[^'"\\\n]+/\n {
append_string(yytext, yyleng);
zconflval.string = text;
return T_WORD_QUOTE;
}
[^'"\\\n]+ {
append_string(yytext, yyleng);
}
\\.?/\n {
append_string(yytext + 1, yyleng - 1);
zconflval.string = text;
return T_WORD_QUOTE;
}
\\.? {
append_string(yytext + 1, yyleng - 1);
}
\'|\" {
if (str == yytext[0]) {
BEGIN(PARAM);
zconflval.string = text;
return T_WORD_QUOTE;
} else
append_string(yytext, 1);
}
\n {
printf("%s:%d:warning: multi-line strings not supported\n", zconf_curname(), zconf_lineno());
current_file->lineno++;
BEGIN(INITIAL);
return T_EOL;
}
<<EOF>> {
BEGIN(INITIAL);
yylval.string = text;
return T_WORD_QUOTE;
}
}
<HELP>{
[ \t]+ {
ts = 0;
for (i = 0; i < yyleng; i++) {
if (yytext[i] == '\t')
ts = (ts & ~7) + 8;
else
ts++;
}
last_ts = ts;
if (first_ts) {
if (ts < first_ts) {
zconf_endhelp();
return T_HELPTEXT;
}
ts -= first_ts;
while (ts > 8) {
append_string(" ", 8);
ts -= 8;
}
append_string(" ", ts);
}
}
[ \t]*\n/[^ \t\n] {
current_file->lineno++;
zconf_endhelp();
return T_HELPTEXT;
}
[ \t]*\n {
current_file->lineno++;
append_string("\n", 1);
}
[^ \t\n].* {
while (yyleng) {
if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
break;
yyleng--;
}
append_string(yytext, yyleng);
if (!first_ts)
first_ts = last_ts;
}
<<EOF>> {
zconf_endhelp();
return T_HELPTEXT;
}
}
<<EOF>> {
if (current_file) {
zconf_endfile();
return T_EOL;
}
fclose(yyin);
yyterminate();
}
%%
void zconf_starthelp(void)
{
new_string();
last_ts = first_ts = 0;
BEGIN(HELP);
}
static void zconf_endhelp(void)
{
zconflval.string = text;
BEGIN(INITIAL);
}
/*
* Try to open specified file with following names:
* ./name
* $(srctree)/name
* The latter is used when srctree is separate from objtree
* when compiling the kernel.
* Return NULL if file is not found.
*/
FILE *zconf_fopen(const char *name)
{
char *env, fullname[PATH_MAX+1];
FILE *f;
f = fopen(name, "r");
if (!f && name != NULL && name[0] != '/') {
env = getenv(SRCTREE);
if (env) {
sprintf(fullname, "%s/%s", env, name);
f = fopen(fullname, "r");
}
}
return f;
}
void zconf_initscan(const char *name)
{
yyin = zconf_fopen(name);
if (!yyin) {
printf("can't find file %s\n", name);
exit(1);
}
current_buf = xmalloc(sizeof(*current_buf));
memset(current_buf, 0, sizeof(*current_buf));
current_file = file_lookup(name);
current_file->lineno = 1;
}
void zconf_nextfile(const char *name)
{
struct file *iter;
struct file *file = file_lookup(name);
struct buffer *buf = xmalloc(sizeof(*buf));
memset(buf, 0, sizeof(*buf));
current_buf->state = YY_CURRENT_BUFFER;
yyin = zconf_fopen(file->name);
if (!yyin) {
printf("%s:%d: can't open file \"%s\"\n",
zconf_curname(), zconf_lineno(), file->name);
exit(1);
}
yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
buf->parent = current_buf;
current_buf = buf;
for (iter = current_file->parent; iter; iter = iter->parent ) {
if (!strcmp(current_file->name,iter->name) ) {
printf("%s:%d: recursive inclusion detected. "
"Inclusion path:\n current file : '%s'\n",
zconf_curname(), zconf_lineno(),
zconf_curname());
iter = current_file->parent;
while (iter && \
strcmp(iter->name,current_file->name)) {
printf(" included from: '%s:%d'\n",
iter->name, iter->lineno-1);
iter = iter->parent;
}
if (iter)
printf(" included from: '%s:%d'\n",
iter->name, iter->lineno+1);
exit(1);
}
}
file->lineno = 1;
file->parent = current_file;
current_file = file;
}
static void zconf_endfile(void)
{
struct buffer *parent;
current_file = current_file->parent;
parent = current_buf->parent;
if (parent) {
fclose(yyin);
yy_delete_buffer(YY_CURRENT_BUFFER);
yy_switch_to_buffer(parent->state);
}
free(current_buf);
current_buf = parent;
}
int zconf_lineno(void)
{
return current_pos.lineno;
}
const char *zconf_curname(void)
{
return current_pos.file ? current_pos.file->name : "<none>";
}