fix(imageio): ignore invalid RowsPerStrip chunking

src/libOpenImageIO/imageinput.cpp

@@ -32,6 +32,14 @@ static thread_local tsl::robin_map<uint64_t, std::string> input_error_messages;
 static std::atomic_int64_t input_next_id(0);
 
 
+static int
+safe_rows_per_strip(const ImageSpec& spec)
+{
+    int rps = spec.get_int_attribute("tiff:RowsPerStrip", 64);
+    return rps > 0 ? rps : 64;
+}
+
+
 class ImageInput::Impl {
 public:
     Impl()
@@ -365,7 +373,7 @@ ImageInput::read_scanlines(int subimage, int miplevel, int ybegin, int yend,
         spec.copy_dimensions(m_spec);
         // For scanline files, we also need one piece of metadata
         if (!spec.tile_width)
-            rps = m_spec.get_int_attribute("tiff:RowsPerStrip", 64);
+            rps = safe_rows_per_strip(m_spec);
         // FIXME: does the above search of metadata have a significant cost?
     }
     if (spec.image_bytes() < 1) {
@@ -1108,7 +1116,7 @@ ImageInput::read_image(int subimage, int miplevel, int chbegin, int chend,
         spec.copy_dimensions(m_spec);
         // For scanline files, we also need one piece of metadata
         if (!spec.tile_width)
-            rps = m_spec.get_int_attribute("tiff:RowsPerStrip", 64);
+            rps = safe_rows_per_strip(m_spec);
     }
     if (spec.image_bytes() < 1) {
         errorfmt("Invalid image size {} x {} ({} chans)", m_spec.width,
@@ -1201,7 +1209,7 @@ ImageInput::read_image(int subimage, int miplevel, int chbegin, int chend,
         spec.copy_dimensions(m_spec);
         // For scanline files, we also need one piece of metadata
         if (!spec.tile_width)
-            rps = m_spec.get_int_attribute("tiff:RowsPerStrip", 64);
+            rps = safe_rows_per_strip(m_spec);
     }
     if (spec.image_bytes() < 1) {
         errorfmt("Invalid image size {} x {} ({} chans)", m_spec.width,

src/libOpenImageIO/imageoutput.cpp

@@ -26,6 +26,16 @@
 
 
 OIIO_NAMESPACE_3_1_BEGIN
+
+
+static int
+safe_rows_per_strip(const ImageSpec& spec)
+{
+    int rps = spec.get_int_attribute("tiff:RowsPerStrip", 64);
+    return rps > 0 ? rps : 64;
+}
+
+
 using namespace pvt;
 using namespace OIIO::pvt;
 
@@ -665,7 +675,7 @@ ImageOutput::write_image(TypeDesc format, const void* data, stride_t xstride,
     } else {  // Scanline image
         // Split into reasonable chunks -- try to use around 64 MB, but
         // round up to a multiple of the TIFF rows per strip (or 64).
-        int rps   = m_spec.get_int_attribute("tiff:RowsPerStrip", 64);
+        int rps   = safe_rows_per_strip(m_spec);
         int chunk = std::max(1, (1 << 26) / int(m_spec.scanline_bytes(true)));
         chunk     = round_to_multiple(chunk, rps);
 

testsuite/invalid-rps-metadata/ref/out.txt

@@ -0,0 +1,14 @@
+Reading negrps.tif
+negrps.tif           :    1 x    1, 3 channel, float tiff
+    SHA-1: 2771C32B635C7C7154A48DBE4F54B3449ABC6B50
+    channel list: R, G, B
+    compression: "zip"
+    DateTime: "2026:07:03 07:11:01"
+    Orientation: 1 (normal)
+    planarconfig: "contig"
+    Software: "OpenImageIO 3.2.0.2dev : 2C50DDDC920616B428C03D5F6786B396201DAF23"
+    oiio:BitsPerSample: 32
+    tiff:Compression: 8
+    tiff:PhotometricInterpretation: 2
+    tiff:PlanarConfiguration: 1
+    tiff:RowsPerStrip: 32

testsuite/invalid-rps-metadata/run.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+
+# Copyright Contributors to the OpenImageIO project.
+# SPDX-License-Identifier: Apache-2.0
+# https://github.com/AcademySoftwareFoundation/OpenImageIO
+
+# save the error output
+redirect = " >> out.txt 2>&1 "
+failureok = 1
+
+# command += oiiotool("-create 2x2 3 -d half -attrib tiff:RowsPerStrip -3 -o negrps.exr")
+command += oiiotool("src/rowsperstrip-zero.exr -o negrps.tif")
+command += info_command("negrps.tif", verbose=True, hash=True)