libpng: patch CVE-2026-22695

Pick commit per [1].
This CVE is regression of fix for CVE-2025-65018.

[1] https://security-tracker.debian.org/tracker/CVE-2026-22695

(From OE-Core rev: 078627f4a208623bc236887682f8a1f0c88f2626)

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Paul Barker <paul@pbarker.dev>

2 files changed, 78 insertions, 0 deletions

diff --git a/meta/recipes-multimedia/libpng/files/CVE-2026-22695.patch b/meta/recipes-multimedia/libpng/files/CVE-2026-22695.patch
new file mode 100644
index 0000000000..673411eb34
--- /dev/null
+++ b/meta/recipes-multimedia/libpng/files/CVE-2026-22695.patch
@@ -0,0 +1,77 @@
+From e4f7ad4ea2a471776c81dda4846b7691925d9786 Mon Sep 17 00:00:00 2001
+From: Cosmin Truta <ctruta@gmail.com>
+Date: Fri, 9 Jan 2026 20:51:53 +0200
+Subject: [PATCH] Fix a heap buffer over-read in `png_image_read_direct_scaled`
+
+Fix a regression from commit 218612ddd6b17944e21eda56caf8b4bf7779d1ea.
+
+The function `png_image_read_direct_scaled`, introduced by the fix for
+CVE-2025-65018, copies transformed row data from an intermediate buffer
+(`local_row`) to the user's output buffer. The copy incorrectly used
+`row_bytes` (the caller's stride) as the size parameter to memcpy, even
+though `local_row` is only `png_get_rowbytes()` bytes long.
+
+This causes a heap buffer over-read when:
+
+1. The caller provides a padded stride (e.g., for memory alignment):
+   memcpy reads past the end of `local_row` by `stride - row_width`
+   bytes.
+
+2. The caller provides a negative stride (for bottom-up layouts):
+   casting ptrdiff_t to size_t produces ~2^64, causing memcpy to
+   attempt reading exabytes, resulting in an immediate crash.
+
+The fix consists in using the size of the row buffer for the copy and
+using the stride for pointer advancement only.
+
+Reported-by: Petr Simecek <simecek@users.noreply.github.com>
+Analyzed-by: Stanislav Fort
+Analyzed-by: Pavel Kohout
+Co-authored-by: Petr Simecek <simecek@users.noreply.github.com>
+Signed-off-by: Cosmin Truta <ctruta@gmail.com>
+
+CVE: CVE-2026-22695
+Upstream-Status: Backport [https://github.com/pnggroup/libpng/commit/e4f7ad4ea2a471776c81dda4846b7691925d9786]
+Signed-off-by: Peter Marko <peter.marko@siemens.com>
+---
+ AUTHORS   | 1 +
+ pngread.c | 4 +++-
+ 2 files changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/AUTHORS b/AUTHORS
+index 26b7bb50f..b9c0fffcf 100644
+--- a/AUTHORS
++++ b/AUTHORS
+@@ -22,6 +22,7 @@ Authors, for copyright and licensing purposes.
+  * Mike Klein
+  * Pascal Massimino
+  * Paul Schmidt
++ * Petr Simecek
+  * Qiang Zhou
+  * Sam Bushell
+  * Samuel Williams
+diff --git a/pngread.c b/pngread.c
+index e3426292b..9d86b01dc 100644
+--- a/pngread.c
++++ b/pngread.c
+@@ -3268,9 +3268,11 @@ png_image_read_direct_scaled(png_voidp argument)
+        argument);
+    png_imagep image = display->image;
+    png_structrp png_ptr = image->opaque->png_ptr;
++   png_inforp info_ptr = image->opaque->info_ptr;
+    png_bytep local_row = png_voidcast(png_bytep, display->local_row);
+    png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+    ptrdiff_t row_bytes = display->row_bytes;
++   size_t copy_bytes = png_get_rowbytes(png_ptr, info_ptr);
+    int passes;
+ 
+    /* Handle interlacing. */
+@@ -3300,7 +3302,7 @@ png_image_read_direct_scaled(png_voidp argument)
+          png_read_row(png_ptr, local_row, NULL);
+ 
+          /* Copy from local_row to user buffer. */
+-         memcpy(output_row, local_row, (size_t)row_bytes);
++         memcpy(output_row, local_row, copy_bytes);
+          output_row += row_bytes;
+       }
+    }
diff --git a/meta/recipes-multimedia/libpng/libpng_1.6.39.bb b/meta/recipes-multimedia/libpng/libpng_1.6.39.bb
index 70685b68e7..9ca68d9b8b 100644
--- a/meta/recipes-multimedia/libpng/libpng_1.6.39.bb
+++ b/meta/recipes-multimedia/libpng/libpng_1.6.39.bb
@@ -22,6 +22,7 @@ SRC_URI = "\
            file://CVE-2025-65018-02.patch \
            file://CVE-2025-66293-01.patch \
            file://CVE-2025-66293-02.patch \
+           file://CVE-2026-22695.patch \
 "
 
 SRC_URI[sha256sum] = "1f4696ce70b4ee5f85f1e1623dc1229b210029fa4b7aee573df3e2ba7b036937"