From 3e7b4242afc10f225b557e3c0b0e355ef5c4de1e Mon Sep 17 00:00:00 2001
From: Ibrahim Burak Yorulmaz <iburaky@gmail.com>
Date: Mon, 6 Apr 2026 04:08:15 +0200
Subject: [PATCH 1/2] dd: exit when bs/ibs/obs/cbs isn't positive

---
 src/uu/dd/src/parseargs.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/uu/dd/src/parseargs.rs b/src/uu/dd/src/parseargs.rs
index 42235cabda5..c1fcd811732 100644
--- a/src/uu/dd/src/parseargs.rs
+++ b/src/uu/dd/src/parseargs.rs
@@ -320,8 +320,12 @@ impl Parser {
     }
 
     fn parse_bytes(arg: &str, val: &str) -> Result<usize, ParseError> {
-        parse_bytes_with_opt_multiplier(val)?
-            .try_into()
+        let num = parse_bytes_with_opt_multiplier(val)?;
+
+        if num == 0 {
+            return Err(ParseError::InvalidNumber(val.to_string()));
+        }
+        num.try_into()
             .map_err(|_| ParseError::BsOutOfRange(arg.to_string()))
     }
 

From ef02de9fb67490360636394d1b0d2bd4d323e221 Mon Sep 17 00:00:00 2001
From: Ibrahim Burak Yorulmaz <iburaky@gmail.com>
Date: Mon, 6 Apr 2026 04:08:35 +0200
Subject: [PATCH 2/2] tests/dd: test supplying non-positive bs/ibs/cbs/obs

---
 tests/by-util/test_dd.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/by-util/test_dd.rs b/tests/by-util/test_dd.rs
index d2dfb7bda2c..f38d770c4b8 100644
--- a/tests/by-util/test_dd.rs
+++ b/tests/by-util/test_dd.rs
@@ -2100,3 +2100,17 @@ fn test_ascii_case_conversion_fallback() {
         .succeeds();
     assert_eq!(result.stdout(), input);
 }
+
+#[test]
+fn test_bs_not_positive() {
+    for bs in [-5, 0, 0x0] {
+        for bs_param in ["bs", "ibs", "obs", "cbs"] {
+            new_ucmd!()
+                .args(&[format!("{bs_param}={bs}")])
+                .fails()
+                .no_stdout()
+                .code_is(1)
+                .stderr_is(format!("dd: invalid number: ‘{bs}’\n"));
+        }
+    }
+}