On Thu, May 10, 2012 at 03:23:39PM -0400, Jeff King wrote:
> I am also tempted to suggest that we simply replace the static buffers
> with dynamic strbufs. I guess that may open up new vectors for an
> attacker to convince git to allocate arbitrary amounts of memory, but
> that is already pretty easy to do, so I doubt it's a big deal.
For reference, that patch would look like something like this:
---
builtin/fmt-merge-msg.c | 14 ++++----
cache.h | 5 ++-
config.c | 4 +--
environment.c | 4 +--
http-push.c | 2 +-
ident.c | 94 ++++++++++++++++++-------------------------------
6 files changed, 50 insertions(+), 73 deletions(-)
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index a517f17..bb716c8 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -230,7 +230,8 @@ static void add_branch_desc(struct strbuf *out, const char *name)
static void record_person(int which, struct string_list *people,
struct commit *commit)
{
- char name_buf[MAX_GITNAME], *name, *name_end;
+ struct strbuf name_buf = STRBUF_INIT;
+ char *name, *name_end;
struct string_list_item *elem;
const char *field = (which == 'a') ? "\nauthor " : "\ncommitter ";
@@ -243,17 +244,18 @@ static void record_person(int which, struct string_list *people,
name_end--;
while (isspace(*name_end) && name <= name_end)
name_end--;
- if (name_end < name || name + MAX_GITNAME <= name_end)
+ if (name_end < name)
return;
- memcpy(name_buf, name, name_end - name + 1);
- name_buf[name_end - name + 1] = '\0';
+ strbuf_add(&name_buf, name, name_end - name + 1);
- elem = string_list_lookup(people, name_buf);
+ elem = string_list_lookup(people, name_buf.buf);
if (!elem) {
- elem = string_list_insert(people, name_buf);
+ elem = string_list_insert(people, name_buf.buf);
elem->util = (void *)0;
}
elem->util = (void*)(util_as_integral(elem) + 1);
+
+ strbuf_release(&name_buf);
}
static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
diff --git a/cache.h b/cache.h
index e14ffcd..0c1a332 100644
--- a/cache.h
+++ b/cache.h
@@ -1138,9 +1138,8 @@ struct config_include_data {
#define CONFIG_INCLUDE_INIT { 0 }
extern int git_config_include(const char *name, const char *value, void *data);
-#define MAX_GITNAME (1000)
-extern char git_default_email[MAX_GITNAME];
-extern char git_default_name[MAX_GITNAME];
+extern struct strbuf git_default_email;
+extern struct strbuf git_default_name;
#define IDENT_NAME_GIVEN 01
#define IDENT_MAIL_GIVEN 02
#define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
diff --git a/config.c b/config.c
index eeee986..69cb08c 100644
--- a/config.c
+++ b/config.c
@@ -767,7 +767,7 @@ static int git_default_user_config(const char *var, const char *value)
if (!strcmp(var, "user.name")) {
if (!value)
return config_error_nonbool(var);
- strlcpy(git_default_name, value, sizeof(git_default_name));
+ strbuf_addstr(&git_default_name, value);
user_ident_explicitly_given |= IDENT_NAME_GIVEN;
return 0;
}
@@ -775,7 +775,7 @@ static int git_default_user_config(const char *var, const char *value)
if (!strcmp(var, "user.email")) {
if (!value)
return config_error_nonbool(var);
- strlcpy(git_default_email, value, sizeof(git_default_email));
+ strbuf_addstr(&git_default_email, value);
user_ident_explicitly_given |= IDENT_MAIL_GIVEN;
return 0;
}
diff --git a/environment.c b/environment.c
index d7e6c65..f4e3b53 100644
--- a/environment.c
+++ b/environment.c
@@ -11,8 +11,8 @@
#include "refs.h"
#include "fmt-merge-msg.h"
-char git_default_email[MAX_GITNAME];
-char git_default_name[MAX_GITNAME];
+struct strbuf git_default_email = STRBUF_INIT;
+struct strbuf git_default_name = STRBUF_INIT;
int user_ident_explicitly_given;
int trust_executable_bit = 1;
int trust_ctime = 1;
diff --git a/http-push.c b/http-push.c
index 1df7ab5..2362ffd 100644
--- a/http-push.c
+++ b/http-push.c
@@ -904,7 +904,7 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
ep = strchr(ep + 1, '/');
}
- escaped = xml_entities(git_default_email);
+ escaped = xml_entities(git_default_email.buf);
strbuf_addf(&out_buffer.buf, LOCK_REQUEST, escaped);
free(escaped);
diff --git a/ident.c b/ident.c
index 87c697c..c7bdb3f 100644
--- a/ident.c
+++ b/ident.c
@@ -15,42 +15,27 @@ static char git_default_date[50];
#define get_gecos(struct_passwd) ((struct_passwd)->pw_gecos)
#endif
-static void copy_gecos(const struct passwd *w, char *name, size_t sz)
+static void copy_gecos(const struct passwd *w, struct strbuf *name)
{
- char *src, *dst;
- size_t len, nlen;
-
- nlen = strlen(w->pw_name);
+ char *src;
/* Traditionally GECOS field had office phone numbers etc, separated
* with commas. Also & stands for capitalized form of the login name.
*/
- for (len = 0, dst = name, src = get_gecos(w); len < sz; src++) {
+ for (src = get_gecos(w); *src && *src != ','; src++) {
int ch = *src;
- if (ch != '&') {
- *dst++ = ch;
- if (ch == 0 || ch == ',')
- break;
- len++;
- continue;
- }
- if (len + nlen < sz) {
+ if (ch != '&')
+ strbuf_addch(name, ch);
+ else {
/* Sorry, Mr. McDonald... */
- *dst++ = toupper(*w->pw_name);
- memcpy(dst, w->pw_name + 1, nlen - 1);
- dst += nlen - 1;
- len += nlen;
+ strbuf_addch(name, toupper(*w->pw_name));
+ strbuf_addstr(name, w->pw_name + 1);
}
}
- if (len < sz)
- name[len] = 0;
- else
- die("Your parents must have hated you!");
-
}
-static int add_mailname_host(char *buf, size_t len)
+static int add_mailname_host(struct strbuf *buf)
{
FILE *mailname;
@@ -61,7 +46,7 @@ static int add_mailname_host(char *buf, size_t len)
strerror(errno));
return -1;
}
- if (!fgets(buf, len, mailname)) {
+ if (strbuf_getline(buf, mailname, '\n') == EOF) {
if (ferror(mailname))
warning("cannot read /etc/mailname: %s",
strerror(errno));
@@ -73,48 +58,41 @@ static int add_mailname_host(char *buf, size_t len)
return 0;
}
-static void add_domainname(char *buf, size_t len)
+static void add_domainname(struct strbuf *out)
{
+ char buf[1024];
struct hostent *he;
- size_t namelen;
const char *domainname;
- if (gethostname(buf, len)) {
+ if (gethostname(buf, sizeof(buf))) {
warning("cannot get host name: %s", strerror(errno));
- strlcpy(buf, "(none)", len);
+ strbuf_addstr(out, "(none)");
return;
}
- namelen = strlen(buf);
- if (memchr(buf, '.', namelen))
+ strbuf_addstr(out, buf);
+ if (strchr(buf, '.'))
return;
he = gethostbyname(buf);
- buf[namelen++] = '.';
- buf += namelen;
- len -= namelen;
+ strbuf_addch(out, '.');
if (he && (domainname = strchr(he->h_name, '.')))
- strlcpy(buf, domainname + 1, len);
+ strbuf_addstr(out, domainname + 1);
else
- strlcpy(buf, "(none)", len);
+ strbuf_addstr(out, "(none)");
}
-static void copy_email(const struct passwd *pw)
+static void copy_email(const struct passwd *pw, struct strbuf *email)
{
/*
* Make up a fake email address
* (name + '@' + hostname [+ '.' + domainname])
*/
- size_t len = strlen(pw->pw_name);
- if (len > sizeof(git_default_email)/2)
- die("Your sysadmin must hate you!");
- memcpy(git_default_email, pw->pw_name, len);
- git_default_email[len++] = '@';
-
- if (!add_mailname_host(git_default_email + len,
- sizeof(git_default_email) - len))
+ strbuf_addstr(email, pw->pw_name);
+ strbuf_addch(email, '@');
+
+ if (!add_mailname_host(email))
return; /* read from "/etc/mailname" (Debian) */
- add_domainname(git_default_email + len,
- sizeof(git_default_email) - len);
+ add_domainname(email);
}
static void setup_ident(const char **name, const char **emailp)
@@ -122,32 +100,31 @@ static void setup_ident(const char **name, const char **emailp)
struct passwd *pw = NULL;
/* Get the name ("gecos") */
- if (!*name && !git_default_name[0]) {
+ if (!*name && !git_default_name.len) {
pw = getpwuid(getuid());
if (!pw)
die("You don't exist. Go away!");
- copy_gecos(pw, git_default_name, sizeof(git_default_name));
+ copy_gecos(pw, &git_default_name);
}
if (!*name)
- *name = git_default_name;
+ *name = git_default_name.buf;
- if (!*emailp && !git_default_email[0]) {
+ if (!*emailp && !git_default_email.len) {
const char *email = getenv("EMAIL");
if (email && email[0]) {
- strlcpy(git_default_email, email,
- sizeof(git_default_email));
+ strbuf_addstr(&git_default_email, email);
user_ident_explicitly_given |= IDENT_MAIL_GIVEN;
} else {
if (!pw)
pw = getpwuid(getuid());
if (!pw)
die("You don't exist. Go away!");
- copy_email(pw);
+ copy_email(pw, &git_default_email);
}
}
if (!*emailp)
- *emailp = git_default_email;
+ *emailp = git_default_email.buf;
/* And set the default date */
if (!git_default_date[0])
@@ -317,7 +294,7 @@ const char *fmt_ident(const char *name, const char *email,
struct passwd *pw;
if ((warn_on_no_name || error_on_no_name) &&
- name == git_default_name && env_hint) {
+ name == git_default_name.buf && env_hint) {
fputs(env_hint, stderr);
env_hint = NULL; /* warn only once */
}
@@ -326,9 +303,8 @@ const char *fmt_ident(const char *name, const char *email,
pw = getpwuid(getuid());
if (!pw)
die("You don't exist. Go away!");
- strlcpy(git_default_name, pw->pw_name,
- sizeof(git_default_name));
- name = git_default_name;
+ strbuf_addstr(&git_default_name, pw->pw_name);
+ name = git_default_name.buf;
}
strcpy(date, git_default_date);
--
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