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Merge pull request #3060 from ethomson/2851

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Handle invalid multiline configuration
This commit is contained in:
Carlos Martín Nieto 2015-04-21 14:04:45 +02:00
commit 3a63e8c299
2 changed files with 93 additions and 62 deletions
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104
src/config_file.c
View File

@ -1162,17 +1162,24 @@ static int skip_bom(struct reader *reader)
static int strip_comments(char *line, int in_quotes)
{
int quote_count = in_quotes;
int quote_count = in_quotes, backslash_count = 0;
char *ptr;
for (ptr = line; *ptr; ++ptr) {
if (ptr[0] == '"' && ptr > line && ptr[-1] != '\\')
quote_count++;
if ((ptr[0] == ';' || ptr[0] == '#') && (quote_count % 2) == 0) {
if ((ptr[0] == ';' || ptr[0] == '#') &&
(quote_count % 2) == 0 &&
(backslash_count % 2) == 0) {
ptr[0] = '\0';
break;
}
if (ptr[0] == '\\')
backslash_count++;
else
backslash_count = 0;
}
/* skip any space at the end */
@ -1619,76 +1626,69 @@ static char *escape_value(const char *ptr)
}
/* '\"' -> '"' etc */
static char *fixup_line(const char *ptr, int quote_count)
static int unescape_line(
char **out, bool *is_multi, const char *ptr, int quote_count)
{
char *str, *out, *esc;
char *str, *fixed, *esc;
size_t ptr_len = strlen(ptr), alloc_len;
*is_multi = false;
if (GIT_ADD_SIZET_OVERFLOW(&alloc_len, ptr_len, 1) ||
(str = git__malloc(alloc_len)) == NULL) {
return NULL;
return -1;
}
out = str;
fixed = str;
while (*ptr != '\0') {
if (*ptr == '"') {
quote_count++;
} else if (*ptr != '\\') {
*out++ = *ptr;
*fixed++ = *ptr;
} else {
/* backslash, check the next char */
ptr++;
/* if we're at the end, it's a multiline, so keep the backslash */
if (*ptr == '\0') {
*out++ = '\\';
goto out;
*is_multi = true;
goto done;
}
if ((esc = strchr(escapes, *ptr)) != NULL) {
*out++ = escaped[esc - escapes];
*fixed++ = escaped[esc - escapes];
} else {
git__free(str);
giterr_set(GITERR_CONFIG, "Invalid escape at %s", ptr);
return NULL;
return -1;
}
}
ptr++;
}
out:
*out = '\0';
done:
*fixed = '\0';
*out = str;
return str;
}
static int is_multiline_var(const char *str)
{
int count = 0;
const char *end = str + strlen(str);
while (end > str && end[-1] == '\\') {
count++;
end--;
}
/* An odd number means last backslash wasn't escaped, so it's multiline */
return count & 1;
return 0;
}
static int parse_multiline_variable(struct reader *reader, git_buf *value, int in_quotes)
{
char *line = NULL, *proc_line = NULL;
int quote_count;
bool multiline;
/* Check that the next line exists */
line = reader_readline(reader, false);
if (line == NULL)
return -1;
/* We've reached the end of the file, there is input missing */
/* We've reached the end of the file, there is no continuation.
* (this is not an error).
*/
if (line[0] == '\0') {
set_parse_error(reader, 0, "Unexpected end of file while parsing multine var");
git__free(line);
return -1;
return 0;
}
quote_count = strip_comments(line, !!in_quotes);
@ -1700,18 +1700,12 @@ static int parse_multiline_variable(struct reader *reader, git_buf *value, int i
/* TODO: unbounded recursion. This **could** be exploitable */
}
/* Drop the continuation character '\': to closely follow the UNIX
* standard, this character **has** to be last one in the buf, with
* no whitespace after it */
assert(is_multiline_var(value->ptr));
git_buf_shorten(value, 1);
proc_line = fixup_line(line, in_quotes);
if (proc_line == NULL) {
if (unescape_line(&proc_line, &multiline, line, in_quotes) < 0) {
git__free(line);
return -1;
}
/* add this line to the multiline var */
git_buf_puts(value, proc_line);
git__free(line);
git__free(proc_line);
@ -1720,7 +1714,7 @@ static int parse_multiline_variable(struct reader *reader, git_buf *value, int i
* If we need to continue reading the next line, let's just
* keep putting stuff in the buffer
*/
if (is_multiline_var(value->ptr))
if (multiline)
return parse_multiline_variable(reader, value, quote_count);
return 0;
@ -1732,6 +1726,7 @@ static int parse_variable(struct reader *reader, char **var_name, char **var_val
const char *value_start = NULL;
char *line;
int quote_count;
bool multiline;
line = reader_readline(reader, true);
if (line == NULL)
@ -1762,31 +1757,28 @@ static int parse_variable(struct reader *reader, char **var_name, char **var_val
while (git__isspace(value_start[0]))
value_start++;
if (is_multiline_var(value_start)) {
if (unescape_line(var_value, &multiline, value_start, 0) < 0)
goto on_error;
if (multiline) {
git_buf multi_value = GIT_BUF_INIT;
char *proc_line = fixup_line(value_start, 0);
GITERR_CHECK_ALLOC(proc_line);
git_buf_puts(&multi_value, proc_line);
git__free(proc_line);
if (parse_multiline_variable(reader, &multi_value, quote_count) < 0 || git_buf_oom(&multi_value)) {
git__free(*var_name);
git__free(line);
git_buf_attach(&multi_value, *var_value, 0);
if (parse_multiline_variable(reader, &multi_value, quote_count) < 0 ||
git_buf_oom(&multi_value)) {
git_buf_free(&multi_value);
return -1;
goto on_error;
}
*var_value = git_buf_detach(&multi_value);
}
else if (value_start[0] != '\0') {
*var_value = fixup_line(value_start, 0);
GITERR_CHECK_ALLOC(*var_value);
} else { /* equals sign but missing rhs */
*var_value = git__strdup("");
GITERR_CHECK_ALLOC(*var_value);
}
}
git__free(line);
return 0;
on_error:
git__free(*var_name);
git__free(line);
return -1;
}

51
tests/config/read.c
View File

@ -69,6 +69,40 @@ void test_config_read__multiline_value(void)
git_config_free(cfg);
}
static void clean_test_config(void *unused)
{
GIT_UNUSED(unused);
cl_fixture_cleanup("./testconfig");
}
void test_config_read__multiline_value_and_eof(void)
{
git_config *cfg;
cl_set_cleanup(&clean_test_config, NULL);
cl_git_mkfile("./testconfig", "[header]\n key1 = foo\\\n");
cl_git_pass(git_config_open_ondisk(&cfg, "./testconfig"));
cl_git_pass(git_config_get_string_buf(&buf, cfg, "header.key1"));
cl_assert_equal_s("foo", git_buf_cstr(&buf));
git_config_free(cfg);
}
void test_config_read__multiline_eof(void)
{
git_config *cfg;
cl_set_cleanup(&clean_test_config, NULL);
cl_git_mkfile("./testconfig", "[header]\n key1 = \\\n");
cl_git_pass(git_config_open_ondisk(&cfg, "./testconfig"));
cl_git_pass(git_config_get_string_buf(&buf, cfg, "header.key1"));
cl_assert_equal_s("", git_buf_cstr(&buf));
git_config_free(cfg);
}
/*
* This kind of subsection declaration is case-insensitive
*/
@ -213,6 +247,17 @@ void test_config_read__escaping_quotes(void)
git_config_free(cfg);
}
void test_config_read__invalid_escape_sequence(void)
{
git_config *cfg;
cl_set_cleanup(&clean_test_config, NULL);
cl_git_mkfile("./testconfig", "[header]\n key1 = \\\\\\;\n key2 = value2\n");
cl_git_fail(git_config_open_ondisk(&cfg, "./testconfig"));
git_config_free(cfg);
}
static int count_cfg_entries_and_compare_levels(
const git_config_entry *entry, void *payload)
{
@ -520,12 +565,6 @@ void test_config_read__simple_read_from_specific_level(void)
git_config_free(cfg);
}
static void clean_test_config(void *unused)
{
GIT_UNUSED(unused);
cl_fixture_cleanup("./testconfig");
}
void test_config_read__can_load_and_parse_an_empty_config_file(void)
{
git_config *cfg;