From 7b487d9146dba07d2e71c27fd3033587c09766b0 Mon Sep 17 00:00:00 2001
From: Scott Boudreaux <121303252+Scottcjn@users.noreply.github.com>
Date: Fri, 26 Jun 2026 17:36:46 +0000
Subject: [PATCH] Core: byte-swap the float vector data, not the attribute
 struct

extract_attr_float_vector reads the float array into attrdata->arr, then
called priv_to_native32(attrdata, n). On big-endian hosts that swaps the
first n 32-bit words of the exr_attr_float_vector_t struct itself (the
arr pointer and length) instead of the n floats in attrdata->arr. The
corrupted pointer and length then crash when the value is read back, for
example a std::bad_alloc or segfault while constructing the FloatVector
in the C++ Context::header path.

Swap attrdata->arr instead. priv_to_native32 is a no-op on little-endian,
so x86_64 and ppc64le are unaffected.

Verified on POWER8: OpenEXR.testAttributes segfaults on big-endian ppc64
before this change and passes after.

Signed-off-by: Scott Boudreaux <121303252+Scottcjn@users.noreply.github.com>
---
 src/lib/OpenEXRCore/parse_header.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/OpenEXRCore/parse_header.c b/src/lib/OpenEXRCore/parse_header.c
index 575707d0e..af0fd2569 100644
--- a/src/lib/OpenEXRCore/parse_header.c
+++ b/src/lib/OpenEXRCore/parse_header.c
@@ -557,7 +557,7 @@ extract_attr_float_vector (
                 tname);
         }
 
-        priv_to_native32 (attrdata, n);
+        priv_to_native32 (attrdata->arr, n);
     }
 
     return rv;