Fix output size limit handling (#121)

* Hopefully fix the limit handling in decompress_with_limit() functions * Add a test for decompression limit from #119. It passes! Thanks, nice work!
Frommi · Aug 20, 2022 · c08ac1c · c08ac1c
1 parent 96ad0b8
commit c08ac1c
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Showing 2 changed files with 24 additions and 7 deletions.
diff --git a/miniz_oxide/src/inflate/mod.rs b/miniz_oxide/src/inflate/mod.rs
@@ -154,14 +154,12 @@ fn decompress_to_vec_inner(
             }
 
             TINFLStatus::HasMoreOutput => {
-                // We need more space, so check if we can resize the buffer and do it.
-                let new_len = ret
-                    .len()
-                    .checked_add(out_pos)
-                    .ok_or(TINFLStatus::HasMoreOutput)?;
-                if new_len > max_output_size {
+                // if the buffer has already reached the size limit, return an error
+                if ret.len() >= max_output_size {
                     return Err(TINFLStatus::HasMoreOutput);
-                };
+                }
+                // calculate the new length, capped at `max_output_size`
+                let new_len = ret.len().saturating_mul(2).min(max_output_size);
                 ret.resize(new_len, 0);
             }
 

diff --git a/miniz_oxide/tests/test.rs b/miniz_oxide/tests/test.rs
@@ -160,6 +160,25 @@ fn issue_75_empty_input_infinite_loop() {
     assert!(&d == &[0]);
 }
 
+#[test]
+fn issue_119_inflate_with_exact_limit() {
+    use miniz_oxide::inflate::{decompress_to_vec_zlib, decompress_to_vec_zlib_with_limit};
+
+    let compressed_data = [
+        120, 156, 237, 217, 65, 17, 194, 0, 16, 192, 192, 122, 193, 94, 13, 240, 232, 128, 12, 28, 160, 2, 53, 53, 130, 139, 220, 227, 118, 21, 228, 159, 227, 13, 0, 212, 126, 211, 1, 0, 176, 208, 99, 58, 0, 0, 22, 122, 78, 7, 0, 192, 66, 223, 233, 0, 0, 88, 200, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208,
+        243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127,
+        1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 247, 116, 0, 0, 44, 116, 78, 7, 0, 192, 66, 215, 116, 0, 0, 44, 244, 154, 14, 0, 128, 133, 62, 211, 1, 0, 176, 144, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5,
+        128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 252, 95, 0, 232, 249, 191, 0, 208, 243, 127, 1, 160, 231, 255, 2, 64, 207, 255, 5, 128, 158, 255, 11, 0, 61, 255, 23, 0, 122, 254, 47, 0, 244, 254, 53, 209, 27, 197
+    ].as_slice();
+
+    let decompressed_size = decompress_to_vec_zlib(compressed_data)
+        .expect("test is not valid, data must correctly decompress when not limited")
+        .len();
+
+    let _ = decompress_to_vec_zlib_with_limit(compressed_data, decompressed_size)
+        .expect(format!("data decompression failed when limited to {}", decompressed_size).as_str());
+}
+
 /*
 #[test]
 fn large_file() {