From d5bd4ad5237508a2c882a7831c4235e3697c3daa Mon Sep 17 00:00:00 2001
From: dot <dot@youknowone.org>
Date: Thu, 8 Oct 2026 19:28:46 +0900
Subject: [PATCH 1/2] Ignore invalid descriptors in os.closerange

Close raw descriptor numbers through the host CRT layer rather than constructing OwnedFd values for possibly closed descriptors. Preserve the half-open range, ignored close errors and Windows invalid-parameter handling.

Assisted-by: Codex:model-version-unavailable
---
 crates/host_env/src/crt_fd.rs             | 7 +++++++
 crates/host_env/src/crt_fd_unsupported.rs | 2 ++
 crates/vm/src/stdlib/os.rs                | 6 +-----
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/crates/host_env/src/crt_fd.rs b/crates/host_env/src/crt_fd.rs
index f06c5aad984..2390dc2aa83 100644
--- a/crates/host_env/src/crt_fd.rs
+++ b/crates/host_env/src/crt_fd.rs
@@ -348,6 +348,13 @@ pub fn close(fd: Owned) -> io::Result<()> {
     _close(fd.into_raw())
 }
 
+pub fn closerange(fd_low: Raw, fd_high: Raw) {
+    for fd in fd_low..fd_high {
+        // The range can contain closed descriptors, so it cannot use Owned.
+        let _ = _close(fd);
+    }
+}
+
 pub fn ftruncate(fd: Borrowed<'_>, len: Offset) -> io::Result<()> {
     let ret = unsafe { suppress_iph!(c::ftruncate(fd.as_raw(), len)) };
     // On Windows, _chsize_s returns 0 on success, or a positive error code (errno value) on failure.
diff --git a/crates/host_env/src/crt_fd_unsupported.rs b/crates/host_env/src/crt_fd_unsupported.rs
index 7fb8a406e32..7b5336a9b98 100644
--- a/crates/host_env/src/crt_fd_unsupported.rs
+++ b/crates/host_env/src/crt_fd_unsupported.rs
@@ -153,6 +153,8 @@ pub fn close(_fd: Owned) -> io::Result<()> {
     Err(ebadf())
 }
 
+pub fn closerange(_fd_low: Raw, _fd_high: Raw) {}
+
 pub fn ftruncate(_fd: Borrowed<'_>, _len: Offset) -> io::Result<()> {
     Err(ebadf())
 }
diff --git a/crates/vm/src/stdlib/os.rs b/crates/vm/src/stdlib/os.rs
index 527643822b8..6f1dcca1556 100644
--- a/crates/vm/src/stdlib/os.rs
+++ b/crates/vm/src/stdlib/os.rs
@@ -272,11 +272,7 @@ pub(super) mod _os {
 
     #[pyfunction]
     fn closerange(fd_low: i32, fd_high: i32) {
-        for fileno in fd_low..fd_high {
-            if let Ok(fd) = unsafe { crt_fd::Owned::try_from_raw(fileno) } {
-                drop(fd);
-            }
-        }
+        crt_fd::closerange(fd_low, fd_high);
     }
 
     #[cfg(any(unix, windows, target_os = "wasi"))]

From 1259e5c980b4fc689522e9539483e9e8d2022e53 Mon Sep 17 00:00:00 2001
From: dot <dot@youknowone.org>
Date: Thu, 8 Oct 2026 19:28:49 +0900
Subject: [PATCH 2/2] Use immediate exit for host process termination

Python os._exit, failed child exec and fatal/watchdog exits must bypass C exit handlers. Call the host CRT _exit on Unix, Windows and WASI while retaining the existing non-host fallback. Normal interpreter termination is unchanged.

Assisted-by: Codex:model-version-unavailable
---
 crates/host_env/src/os.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/crates/host_env/src/os.rs b/crates/host_env/src/os.rs
index 6eda6030c83..7d6879984bd 100644
--- a/crates/host_env/src/os.rs
+++ b/crates/host_env/src/os.rs
@@ -520,7 +520,11 @@ pub fn device_encoding(_fd: i32) -> Option<String> {
 }
 
 pub fn exit(code: i32) -> ! {
-    std::process::exit(code)
+    // These callers require immediate termination without C exit handlers.
+    cfg_select! {
+        any(unix, windows, target_os = "wasi") => unsafe { libc::_exit(code) },
+        _ => std::process::exit(code),
+    }
 }
 
 /// Wrapper around the C `abort()` call: terminates the process abnormally.