release v0.9.6: --auto no longer prompts for sudo password
release / build (arm64) (push) Waiting to run
release / build (x86_64) (push) Waiting to run
release / build (x86_64-static / musl) (push) Waiting to run
release / build (arm64-static / musl) (push) Waiting to run
release / release (push) Blocked by required conditions

sudo_runas_neg1 and sudoedit_editor's detect() bodies invoked
'sudo -ln' (intending list + non-interactive). Some sudoers / PAM
configurations have been observed prompting for a password anyway
when the flags are bundled. That meant skeletonkey --auto --i-know
could hang on a sudo password prompt during the corpus scan — bad
ergonomics for an LPE tool whose whole point is to get root without
already having it.

Fix: write '-n -l' as separate flags, redirect stdin from /dev/null
so sudo cannot fall back to reading the tty even if PAM tries to
coerce one. Belt-and-suspenders against any tty prompt during --auto.
This commit is contained in:
KaraZajac
2026-05-28 21:50:26 -04:00
parent 13fbbce618
commit 25c2afc3e9
6 changed files with 37 additions and 7 deletions
@@ -106,7 +106,9 @@ static bool get_sudo_version(const char *sudo_path, char *out, size_t outsz)
static bool find_runas_blacklist_grant(const char *sudo_path, char *cmd_out, size_t cap)
{
char cmd[512];
snprintf(cmd, sizeof cmd, "%s -ln 2>/dev/null", sudo_path);
/* -n -l separated + stdin closed: see sudoedit_editor for the same
* pattern + rationale. `--auto` must never block on a tty prompt. */
snprintf(cmd, sizeof cmd, "%s -n -l </dev/null 2>/dev/null", sudo_path);
FILE *p = popen(cmd, "r");
if (!p) return false;
char line[512];
@@ -149,8 +149,13 @@ static bool get_sudo_version(const char *sudo_path, char *out, size_t outsz)
static bool find_sudoedit_target(const char *sudo_path, char *out, size_t outsz)
{
char cmd[512];
/* -n: non-interactive (no password prompt); -l: list. */
snprintf(cmd, sizeof cmd, "%s -ln 2>&1", sudo_path);
/* -n: non-interactive (no password prompt); -l: list. The two flags
* are written separately and stdin is redirected from /dev/null so
* sudo cannot fall back to a tty prompt even if the local PAM stack
* tries to coerce one (some sudoers + pam_unix configurations have
* been observed prompting despite `-n` when the flags are bundled
* as `-ln`). Belt-and-suspenders so `--auto` never blocks on input. */
snprintf(cmd, sizeof cmd, "%s -n -l </dev/null 2>&1", sudo_path);
FILE *p = popen(cmd, "r");
if (!p) return false;