From 62aa0f5fef2751d5d33e2a38d711a31e7b087bbb Mon Sep 17 00:00:00 2001
From: fixfon <12512757+fixfon@users.noreply.github.com>
Date: Sun, 25 Oct 2026 16:44:19 +0300
Subject: [PATCH] tee: handle closed stdin

Refs #10154
---
 src/uu/tee/src/tee.rs     |  9 +++++++++
 tests/by-util/test_tee.rs | 15 +++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/uu/tee/src/tee.rs b/src/uu/tee/src/tee.rs
index 3b87b2cb076..29409fff26f 100644
--- a/src/uu/tee/src/tee.rs
+++ b/src/uu/tee/src/tee.rs
@@ -147,6 +147,15 @@ impl MultiWriter {
         #[cfg(not(any(unix, target_os = "wasi")))]
         use io::Read as _;
         const BUF_SIZE: usize = 32 * 1024;
+        #[cfg(all(unix, not(target_os = "fuchsia")))]
+        if uucore::signals::stdin_was_closed() {
+            let e = Error::from(rustix::io::Errno::BADF);
+            show_error!(
+                "{}",
+                translate!("tee-error-stdin", "error" => strip_errno(&e))
+            );
+            return Err(());
+        }
         #[cfg(any(unix, target_os = "wasi"))]
         let input = rustix::stdio::stdin();
         #[cfg(not(any(unix, target_os = "wasi")))]
diff --git a/tests/by-util/test_tee.rs b/tests/by-util/test_tee.rs
index 3595e22c8ed..8f7b7e455e4 100644
--- a/tests/by-util/test_tee.rs
+++ b/tests/by-util/test_tee.rs
@@ -26,6 +26,21 @@ fn test_error_stdin_directory() {
         .stderr_is("tee: read error: Is a directory\n");
 }
 
+#[test]
+#[cfg(all(unix, not(wasi_runner)))]
+fn test_closed_stdin() {
+    // Reading a closed stdin fails with EBADF. Run through a shell so the
+    // process really starts with fd 0 closed.
+    let (at, ts) = ::uutests::at_and_ts!();
+    ts.cmd("sh")
+        .args(&["-c", "exec <&-; \"$0\" tee file"])
+        .arg(&ts.bin_path)
+        .fails_with_code(1)
+        .no_stdout()
+        .stderr_is("tee: read error: Bad file descriptor\n");
+    assert_eq!(at.read("file"), "");
+}
+
 #[test]
 fn test_invalid_arg() {
     new_ucmd!().arg("--definitely-invalid").fails_with_code(1);