Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC
The `struct attr_stack` tracks the stack of all patterns together with their attributes. When parsing a gitattributes file that has more than 2^31 such patterns though we may trigger multiple out-of-bounds reads on 64 bit platforms. This is because while the `num_matches` variable is an unsigned integer, we always use a signed integer to iterate over them. I have not been able to reproduce this issue due to memory constraints on my systems. But despite the out-of-bounds reads, the worst thing that can seemingly happen is to call free(3P) with a garbage pointer when calling `attr_stack_free()`. Fix this bug by using unsigned integers to iterate over the array. While this makes the iteration somewhat awkward when iterating in reverse, it is at least better than knowingly running into an out-of-bounds read. While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
mailmap.c
#include "cache.h"
#include "string-list.h"
#include "mailmap.h"
#include "object-store.h"
#define DEBUG_MAILMAP 0
#if DEBUG_MAILMAP
#define debug_mm(...) fprintf(stderr, __VA_ARGS__)
#define debug_str(X) ((X) ? (X) : "(none)")
#else
static inline void debug_mm(const char *format, ...) {}
static inline const char *debug_str(const char *s) { return s; }
#endif
const char *git_mailmap_file;
const char *git_mailmap_blob;
struct mailmap_info {
char *name;
char *email;
};
struct mailmap_entry {
/* name and email for the simple mail-only case */
char *name;
char *email;
/* name and email for the complex mail and name matching case */
struct string_list namemap;
};
static void free_mailmap_info(void *p, const char *s)
{
struct mailmap_info *mi = (struct mailmap_info *)p;
debug_mm("mailmap: -- complex: '%s' -> '%s' <%s>\n",
s, debug_str(mi->name), debug_str(mi->email));
free(mi->name);
free(mi->email);
}
static void free_mailmap_entry(void *p, const char *s)
{
struct mailmap_entry *me = (struct mailmap_entry *)p;
debug_mm("mailmap: removing entries for <%s>, with %d sub-entries\n",
s, me->namemap.nr);
debug_mm("mailmap: - simple: '%s' <%s>\n",
debug_str(me->name), debug_str(me->email));
free(me->name);
free(me->email);
me->namemap.strdup_strings = 1;
string_list_clear_func(&me->namemap, free_mailmap_info);
}
/*
* On some systems (e.g. MinGW 4.0), string.h has _only_ inline
* definition of strcasecmp and no non-inline implementation is
* supplied anywhere, which is, eh, "unusual"; we cannot take an
* address of such a function to store it in namemap.cmp. This is
* here as a workaround---do not assign strcasecmp directly to
* namemap.cmp until we know no systems that matter have such an
* "unusual" string.h.
*/
static int namemap_cmp(const char *a, const char *b)
{
return strcasecmp(a, b);
}
static void add_mapping(struct string_list *map,
char *new_name, char *new_email,
char *old_name, char *old_email)
{
struct mailmap_entry *me;
struct string_list_item *item;
if (old_email == NULL) {
old_email = new_email;
new_email = NULL;
}
item = string_list_insert(map, old_email);
if (item->util) {
me = (struct mailmap_entry *)item->util;
} else {
me = xcalloc(1, sizeof(struct mailmap_entry));
me->namemap.strdup_strings = 1;
me->namemap.cmp = namemap_cmp;
item->util = me;
}
if (old_name == NULL) {
debug_mm("mailmap: adding (simple) entry for '%s'\n", old_email);
/* Replace current name and new email for simple entry */
if (new_name) {
free(me->name);
me->name = xstrdup(new_name);
}
if (new_email) {
free(me->email);
me->email = xstrdup(new_email);
}
} else {
struct mailmap_info *mi = xcalloc(1, sizeof(struct mailmap_info));
debug_mm("mailmap: adding (complex) entry for '%s'\n", old_email);
mi->name = xstrdup_or_null(new_name);
mi->email = xstrdup_or_null(new_email);
string_list_insert(&me->namemap, old_name)->util = mi;
}
debug_mm("mailmap: '%s' <%s> -> '%s' <%s>\n",
debug_str(old_name), old_email,
debug_str(new_name), debug_str(new_email));
}
static char *parse_name_and_email(char *buffer, char **name,
char **email, int allow_empty_email)
{
char *left, *right, *nstart, *nend;
*name = *email = NULL;
if ((left = strchr(buffer, '<')) == NULL)
return NULL;
if ((right = strchr(left+1, '>')) == NULL)
return NULL;
if (!allow_empty_email && (left+1 == right))
return NULL;
/* remove whitespace from beginning and end of name */
nstart = buffer;
while (isspace(*nstart) && nstart < left)
++nstart;
nend = left-1;
while (nend > nstart && isspace(*nend))
--nend;
*name = (nstart <= nend ? nstart : NULL);
*email = left+1;
*(nend+1) = '\0';
*right++ = '\0';
return (*right == '\0' ? NULL : right);
}
static void read_mailmap_line(struct string_list *map, char *buffer,
char **repo_abbrev)
{
char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;
if (buffer[0] == '#') {
static const char abbrev[] = "# repo-abbrev:";
int abblen = sizeof(abbrev) - 1;
int len = strlen(buffer);
if (!repo_abbrev)
return;
if (len && buffer[len - 1] == '\n')
buffer[--len] = 0;
if (!strncmp(buffer, abbrev, abblen)) {
char *cp;
free(*repo_abbrev);
for (cp = buffer + abblen; isspace(*cp); cp++)
; /* nothing */
*repo_abbrev = xstrdup(cp);
}
return;
}
if ((name2 = parse_name_and_email(buffer, &name1, &email1, 0)) != NULL)
parse_name_and_email(name2, &name2, &email2, 1);
if (email1)
add_mapping(map, name1, email1, name2, email2);
}
static int read_mailmap_file(struct string_list *map, const char *filename,
char **repo_abbrev)
{
char buffer[1024];
FILE *f;
if (!filename)
return 0;
f = fopen(filename, "r");
if (!f) {
if (errno == ENOENT)
return 0;
return error_errno("unable to open mailmap at %s", filename);
}
while (fgets(buffer, sizeof(buffer), f) != NULL)
read_mailmap_line(map, buffer, repo_abbrev);
fclose(f);
return 0;
}
static void read_mailmap_string(struct string_list *map, char *buf,
char **repo_abbrev)
{
while (*buf) {
char *end = strchrnul(buf, '\n');
if (*end)
*end++ = '\0';
read_mailmap_line(map, buf, repo_abbrev);
buf = end;
}
}
static int read_mailmap_blob(struct string_list *map,
const char *name,
char **repo_abbrev)
{
struct object_id oid;
char *buf;
unsigned long size;
enum object_type type;
if (!name)
return 0;
if (get_oid(name, &oid) < 0)
return 0;
buf = read_object_file(&oid, &type, &size);
if (!buf)
return error("unable to read mailmap object at %s", name);
if (type != OBJ_BLOB)
return error("mailmap is not a blob: %s", name);
read_mailmap_string(map, buf, repo_abbrev);
free(buf);
return 0;
}
int read_mailmap(struct string_list *map, char **repo_abbrev)
{
int err = 0;
map->strdup_strings = 1;
map->cmp = namemap_cmp;
if (!git_mailmap_blob && is_bare_repository())
git_mailmap_blob = "HEAD:.mailmap";
err |= read_mailmap_file(map, ".mailmap", repo_abbrev);
if (startup_info->have_repository)
err |= read_mailmap_blob(map, git_mailmap_blob, repo_abbrev);
err |= read_mailmap_file(map, git_mailmap_file, repo_abbrev);
return err;
}
void clear_mailmap(struct string_list *map)
{
debug_mm("mailmap: clearing %d entries...\n", map->nr);
map->strdup_strings = 1;
string_list_clear_func(map, free_mailmap_entry);
debug_mm("mailmap: cleared\n");
}
/*
* Look for an entry in map that match string[0:len]; string[len]
* does not have to be NUL (but it could be).
*/
static struct string_list_item *lookup_prefix(struct string_list *map,
const char *string, size_t len)
{
int i = string_list_find_insert_index(map, string, 1);
if (i < 0) {
/* exact match */
i = -1 - i;
if (!string[len])
return &map->items[i];
/*
* that map entry matches exactly to the string, including
* the cruft at the end beyond "len". That is not a match
* with string[0:len] that we are looking for.
*/
} else if (!string[len]) {
/*
* asked with the whole string, and got nothing. No
* matching entry can exist in the map.
*/
return NULL;
}
/*
* i is at the exact match to an overlong key, or location the
* overlong key would be inserted, which must come after the
* real location of the key if one exists.
*/
while (0 <= --i && i < map->nr) {
int cmp = strncasecmp(map->items[i].string, string, len);
if (cmp < 0)
/*
* "i" points at a key definitely below the prefix;
* the map does not have string[0:len] in it.
*/
break;
else if (!cmp && !map->items[i].string[len])
/* found it */
return &map->items[i];
/*
* otherwise, the string at "i" may be string[0:len]
* followed by a string that sorts later than string[len:];
* keep trying.
*/
}
return NULL;
}
int map_user(struct string_list *map,
const char **email, size_t *emaillen,
const char **name, size_t *namelen)
{
struct string_list_item *item;
struct mailmap_entry *me;
debug_mm("map_user: map '%.*s' <%.*s>\n",
(int)*namelen, debug_str(*name),
(int)*emaillen, debug_str(*email));
item = lookup_prefix(map, *email, *emaillen);
if (item != NULL) {
me = (struct mailmap_entry *)item->util;
if (me->namemap.nr) {
/*
* The item has multiple items, so we'll look up on
* name too. If the name is not found, we choose the
* simple entry.
*/
struct string_list_item *subitem;
subitem = lookup_prefix(&me->namemap, *name, *namelen);
if (subitem)
item = subitem;
}
}
if (item != NULL) {
struct mailmap_info *mi = (struct mailmap_info *)item->util;
if (mi->name == NULL && mi->email == NULL) {
debug_mm("map_user: -- (no simple mapping)\n");
return 0;
}
if (mi->email) {
*email = mi->email;
*emaillen = strlen(*email);
}
if (mi->name) {
*name = mi->name;
*namelen = strlen(*name);
}
debug_mm("map_user: to '%.*s' <%.*s>\n",
(int)*namelen, debug_str(*name),
(int)*emaillen, debug_str(*email));
return 1;
}
debug_mm("map_user: --\n");
return 0;
}
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