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authorPhillip Wood <phillip.wood@dunelm.org.uk>2025-07-15 15:00:56 +0100
committerJunio C Hamano <gitster@pobox.com>2025-07-15 12:21:48 -0700
commit14d7583beb020a4b3c388f8b7ea580cf2a156ff8 (patch)
tree9517d21005f930ca4e07bd4e4cc12648439467ac /config.c
parent16bd9f20a403117f2e0d9bcda6c6e621d3763e77 (diff)
downloadgit-14d7583beb020a4b3c388f8b7ea580cf2a156ff8.tar.gz
config: remove unneeded struct field
As well as receiving the config key and value, config callbacks also receive a "struct key_value_info" containing information about the source of the key-value pair. Accessing the "path" field of this struct from a callback passed to repo_config() results in a use-after-free. This happens because repo_config() first populates a configset by calling config_with_options() and then iterates over the configset with the callback passed by the caller. When the configset is constructed it takes a shallow copy of the "struct key_value_info" for each config setting. This leads to the use-after-free as the "path" member is freed before config_with_options() returns. We could fix this by interning the "path" field as we do for the "filename" field but the "path" field is not actually needed. It is populated with a copy of the "path" field from "struct config_source". That field was added in d14d42440d8 (config: disallow relative include paths from blobs, 2014-02-19) to distinguish between relative include directives in files and those in blobs. However, since 1b8132d99d8 (i18n: config: unfold error messages marked for translation, 2016-07-28) we can differentiate these by looking at the "origin_type" field in "struct key_value_info". So let's remove the "path" members from "struct config_source" and "struct key_value_info" and instead use a combination of the "filename" and "origin_type" fields to determine the absolute path of relative includes. Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'config.c')
-rw-r--r--config.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/config.c b/config.c
index b18b5617fc..85883afb6c 100644
--- a/config.c
+++ b/config.c
@@ -56,7 +56,6 @@ struct config_source {
} u;
enum config_origin_type origin_type;
const char *name;
- const char *path;
enum config_error_action default_error_action;
int linenr;
int eof;
@@ -173,14 +172,14 @@ static int handle_path_include(const struct key_value_info *kvi,
if (!is_absolute_path(path)) {
char *slash;
- if (!kvi || !kvi->path) {
+ if (!kvi || kvi->origin_type != CONFIG_ORIGIN_FILE) {
ret = error(_("relative config includes must come from files"));
goto cleanup;
}
- slash = find_last_dir_sep(kvi->path);
+ slash = find_last_dir_sep(kvi->filename);
if (slash)
- strbuf_add(&buf, kvi->path, slash - kvi->path + 1);
+ strbuf_add(&buf, kvi->filename, slash - kvi->filename + 1);
strbuf_addstr(&buf, path);
path = buf.buf;
}
@@ -224,11 +223,11 @@ static int prepare_include_condition_pattern(const struct key_value_info *kvi,
if (pat->buf[0] == '.' && is_dir_sep(pat->buf[1])) {
const char *slash;
- if (!kvi || !kvi->path)
+ if (!kvi || kvi->origin_type != CONFIG_ORIGIN_FILE)
return error(_("relative config include "
"conditionals must come from files"));
- strbuf_realpath(&path, kvi->path, 1);
+ strbuf_realpath(&path, kvi->filename, 1);
slash = find_last_dir_sep(path.buf);
if (!slash)
BUG("how is this possible?");
@@ -633,7 +632,6 @@ void kvi_from_param(struct key_value_info *out)
out->linenr = -1;
out->origin_type = CONFIG_ORIGIN_CMDLINE;
out->scope = CONFIG_SCOPE_COMMAND;
- out->path = NULL;
}
int git_config_parse_parameter(const char *text,
@@ -1036,7 +1034,6 @@ static void kvi_from_source(struct config_source *cs,
out->origin_type = cs->origin_type;
out->linenr = cs->linenr;
out->scope = scope;
- out->path = cs->path;
}
static int git_parse_source(struct config_source *cs, config_fn_t fn,
@@ -1855,17 +1852,19 @@ static int do_config_from(struct config_source *top, config_fn_t fn,
static int do_config_from_file(config_fn_t fn,
const enum config_origin_type origin_type,
- const char *name, const char *path, FILE *f,
- void *data, enum config_scope scope,
+ const char *name, FILE *f, void *data,
+ enum config_scope scope,
const struct config_options *opts)
{
struct config_source top = CONFIG_SOURCE_INIT;
int ret;
+ if (origin_type == CONFIG_ORIGIN_FILE && (!name || !*name))
+ BUG("missing filename for CONFIG_ORIGIN_FILE");
+
top.u.file = f;
top.origin_type = origin_type;
top.name = name;
- top.path = path;
top.default_error_action = CONFIG_ERROR_DIE;
top.do_fgetc = config_file_fgetc;
top.do_ungetc = config_file_ungetc;
@@ -1880,8 +1879,8 @@ static int do_config_from_file(config_fn_t fn,
static int git_config_from_stdin(config_fn_t fn, void *data,
enum config_scope scope)
{
- return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin,
- data, scope, NULL);
+ return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", stdin, data,
+ scope, NULL);
}
int git_config_from_file_with_options(config_fn_t fn, const char *filename,
@@ -1896,7 +1895,7 @@ int git_config_from_file_with_options(config_fn_t fn, const char *filename,
f = fopen_or_warn(filename, "r");
if (f) {
ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename,
- filename, f, data, scope, opts);
+ f, data, scope, opts);
fclose(f);
}
return ret;
@@ -1921,7 +1920,6 @@ int git_config_from_mem(config_fn_t fn,
top.u.buf.pos = 0;
top.origin_type = origin_type;
top.name = name;
- top.path = NULL;
top.default_error_action = CONFIG_ERROR_ERROR;
top.do_fgetc = config_buf_fgetc;
top.do_ungetc = config_buf_ungetc;