backtrace: Check the return values of snprintf() and strncpy()

We can't use strlcat() or strlcpy() in torerr, because they are defined
in string/compat_string.h on some platforms, and string uses torerr.

Part of 31571.
This commit is contained in:
teor 2019-09-03 15:50:37 +10:00
parent c55591825f
commit f311d0676c

View File

@ -276,11 +276,23 @@ configure_backtrace_handler(const char *tor_version)
char version[128] = "Tor\0";
if (tor_version) {
snprintf(version, sizeof(version), "Tor %s", tor_version);
int snp_rv = 0;
/* We can't use strlcat() here, because it is defined in
* string/compat_string.h on some platforms, and string uses torerr. */
snp_rv = snprintf(version, sizeof(version), "Tor %s", tor_version);
/* It's safe to call raw_assert() here, because raw_assert() does not
* call configure_backtrace_handler(). */
raw_assert(snp_rv < (int)sizeof(version));
raw_assert(snp_rv >= 0);
}
strncpy(bt_version, version, sizeof(bt_version) - 1);
char *str_rv = NULL;
/* We can't use strlcpy() here, see the note about strlcat() above. */
str_rv = strncpy(bt_version, version, sizeof(bt_version) - 1);
/* We must terminate bt_version, then raw_assert(), because raw_assert()
* uses bt_version. */
bt_version[sizeof(bt_version) - 1] = 0;
raw_assert(str_rv == bt_version);
return install_bt_handler();
}