From patchwork Thu Nov 27 18:03:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Peter Marko X-Patchwork-Id: 75498 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFA01CFD2F6 for ; Thu, 27 Nov 2025 18:04:13 +0000 (UTC) Received: from mta-64-226.siemens.flowmailer.net (mta-64-226.siemens.flowmailer.net [185.136.64.226]) by mx.groups.io with SMTP id smtpd.msgproc02-g2.707.1764266643632825960 for ; Thu, 27 Nov 2025 10:04:03 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=peter.marko@siemens.com header.s=fm1 header.b=cH/NjAUd; spf=pass (domain: rts-flowmailer.siemens.com, ip: 185.136.64.226, mailfrom: fm-256628-202511271804015b2efb6d13000207ba-86qma1@rts-flowmailer.siemens.com) Received: by mta-64-226.siemens.flowmailer.net with ESMTPSA id 202511271804015b2efb6d13000207ba for ; Thu, 27 Nov 2025 19:04:01 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=peter.marko@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=U5ndyinzTrKgmgjX+/25dZbUIDrgSm4kYedPXoxMSmo=; b=cH/NjAUdt1765DsNcT5bdwMVyjcah7XMww2LwV80MOsVlu+WKR/bNx8qjst3p0mPQ6+iti jelNnnd0hdYLF9PHySVTIWLroaLc1FoqZy9rPy/zYytZ9EWq/WsB2CLHFDXO2XOCakvmXpsJ KWlgdItvgoazo502jo4BCVXz0x/cr7exMCs2TG9FC+IXo2TOut0PL1m9+4Gd/zMNzd1hpWqd yrWr+ZEF1CKUMSjoW0TXCsua6LFOT/kKM1nCpU9C1HbDL6wLqNdVLcnZgb0B1KJnYA9upEb5 K1PbrJQiFvqdZQMpB2SQgIOV/lGsYXoikfdy+6EHDJFo3xLmgcZk6YgA==; From: Peter Marko To: openembedded-core@lists.openembedded.org Cc: Peter Marko Subject: [OE-core][kirkstone][PATCH 4/4] libpng: patch CVE-2025-65018 Date: Thu, 27 Nov 2025 19:03:48 +0100 Message-Id: <20251127180348.3347694-4-peter.marko@siemens.com> In-Reply-To: <20251127180348.3347694-1-peter.marko@siemens.com> References: <20251127180348.3347694-1-peter.marko@siemens.com> MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-256628:519-21489:flowmailer List-Id: X-Webhook-Received: from 45-33-107-173.ip.linodeusercontent.com [45.33.107.173] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Thu, 27 Nov 2025 18:04:13 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/226863 From: Peter Marko Pick commits per NVD report. Signed-off-by: Peter Marko --- .../libpng/files/CVE-2025-65018-01.patch | 60 +++++++ .../libpng/files/CVE-2025-65018-02.patch | 163 ++++++++++++++++++ .../libpng/libpng_1.6.39.bb | 2 + 3 files changed, 225 insertions(+) create mode 100644 meta/recipes-multimedia/libpng/files/CVE-2025-65018-01.patch create mode 100644 meta/recipes-multimedia/libpng/files/CVE-2025-65018-02.patch diff --git a/meta/recipes-multimedia/libpng/files/CVE-2025-65018-01.patch b/meta/recipes-multimedia/libpng/files/CVE-2025-65018-01.patch new file mode 100644 index 00000000000..a3e31ea6ac3 --- /dev/null +++ b/meta/recipes-multimedia/libpng/files/CVE-2025-65018-01.patch @@ -0,0 +1,60 @@ +From 16b5e3823918840aae65c0a6da57c78a5a496a4d Mon Sep 17 00:00:00 2001 +From: Cosmin Truta +Date: Mon, 17 Nov 2025 20:38:47 +0200 +Subject: [PATCH] Fix a buffer overflow in `png_image_finish_read` +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Reject bit-depth mismatches between IHDR and the requested output +format. When a 16-bit PNG is processed with an 8-bit output format +request, `png_combine_row` writes using the IHDR depth before +transformation, causing writes beyond the buffer allocated via +`PNG_IMAGE_SIZE(image)`. + +The validation establishes a safe API contract where +`PNG_IMAGE_SIZE(image)` is guaranteed to be sufficient across the +transformation pipeline. + +Example overflow (32×32 pixels, 16-bit RGB to 8-bit RGBA): +- Input format: 16 bits/channel × 3 channels = 6144 bytes +- Output buffer: 8 bits/channel × 4 channels = 4096 bytes +- Overflow: 6144 bytes - 4096 bytes = 2048 bytes + +Larger images produce proportionally larger overflows. For example, +for 256×256 pixels, the overflow is 131072 bytes. + +Reported-by: yosiimich + +CVE: CVE-2025-65018 +Upstream-Status: Backport [https://github.com/pnggroup/libpng/commit/16b5e3823918840aae65c0a6da57c78a5a496a4d] +Signed-off-by: Peter Marko +--- + pngread.c | 14 ++++++++++++++ + 1 file changed, 14 insertions(+) + +diff --git a/pngread.c b/pngread.c +index 212afb7d2..92571ec33 100644 +--- a/pngread.c ++++ b/pngread.c +@@ -4164,6 +4164,20 @@ png_image_finish_read(png_imagep image, png_const_colorp background, + int result; + png_image_read_control display; + ++ /* Reject bit depth mismatches to avoid buffer overflows. */ ++ png_uint_32 ihdr_bit_depth = ++ image->opaque->png_ptr->bit_depth; ++ int requested_linear = ++ (image->format & PNG_FORMAT_FLAG_LINEAR) != 0; ++ if (ihdr_bit_depth == 16 && !requested_linear) ++ return png_image_error(image, ++ "png_image_finish_read: " ++ "16-bit PNG must use 16-bit output format"); ++ if (ihdr_bit_depth < 16 && requested_linear) ++ return png_image_error(image, ++ "png_image_finish_read: " ++ "8-bit PNG must not use 16-bit output format"); ++ + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; diff --git a/meta/recipes-multimedia/libpng/files/CVE-2025-65018-02.patch b/meta/recipes-multimedia/libpng/files/CVE-2025-65018-02.patch new file mode 100644 index 00000000000..b64a45e9f3f --- /dev/null +++ b/meta/recipes-multimedia/libpng/files/CVE-2025-65018-02.patch @@ -0,0 +1,163 @@ +From 218612ddd6b17944e21eda56caf8b4bf7779d1ea Mon Sep 17 00:00:00 2001 +From: Cosmin Truta +Date: Wed, 19 Nov 2025 21:45:13 +0200 +Subject: [PATCH] Rearchitect the fix to the buffer overflow in + `png_image_finish_read` + +Undo the fix from commit 16b5e3823918840aae65c0a6da57c78a5a496a4d. +That fix turned out to be unnecessarily limiting. It rejected all +16-to-8 bit transformations, although the vulnerability only affects +interlaced PNGs where `png_combine_row` writes using IHDR bit-depth +before the transformation completes. + +The proper solution is to add an intermediate `local_row` buffer, +specifically for the slow but necessary step of 16-to-8 bit conversion +of interlaced images. (The processing of non-interlaced images remains +intact, using the fast path.) We added the flag `do_local_scale` and +the function `png_image_read_direct_scaled`, following the pattern that +involves `do_local_compose`. + +In conclusion: +- The 16-to-8 bit transformations of interlaced images are now safe, + as they use an intermediate buffer. +- The 16-to-8 bit transformations of non-interlaced images remain safe, + as the fast path remains unchanged. +- All our regression tests are now passing. + +CVE: CVE-2025-65018 +Upstream-Status: Backport [https://github.com/pnggroup/libpng/commit/218612ddd6b17944e21eda56caf8b4bf7779d1ea] +Signed-off-by: Peter Marko +--- + pngread.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++--------- + 1 file changed, 75 insertions(+), 14 deletions(-) + +diff --git a/pngread.c b/pngread.c +index 92571ec33..79917daaa 100644 +--- a/pngread.c ++++ b/pngread.c +@@ -3260,6 +3260,54 @@ png_image_read_colormapped(png_voidp argument) + } + } + ++/* Row reading for interlaced 16-to-8 bit depth conversion with local buffer. */ ++static int ++png_image_read_direct_scaled(png_voidp argument) ++{ ++ png_image_read_control *display = png_voidcast(png_image_read_control*, ++ argument); ++ png_imagep image = display->image; ++ png_structrp png_ptr = image->opaque->png_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; ++ int passes; ++ ++ /* Handle interlacing. */ ++ switch (png_ptr->interlaced) ++ { ++ case PNG_INTERLACE_NONE: ++ passes = 1; ++ break; ++ ++ case PNG_INTERLACE_ADAM7: ++ passes = PNG_INTERLACE_ADAM7_PASSES; ++ break; ++ ++ default: ++ png_error(png_ptr, "unknown interlace type"); ++ } ++ ++ /* Read each pass using local_row as intermediate buffer. */ ++ while (--passes >= 0) ++ { ++ png_uint_32 y = image->height; ++ png_bytep output_row = first_row; ++ ++ for (; y > 0; --y) ++ { ++ /* Read into local_row (gets transformed 8-bit data). */ ++ png_read_row(png_ptr, local_row, NULL); ++ ++ /* Copy from local_row to user buffer. */ ++ memcpy(output_row, local_row, (size_t)row_bytes); ++ output_row += row_bytes; ++ } ++ } ++ ++ return 1; ++} ++ + /* Just the row reading part of png_image_read. */ + static int + png_image_read_composite(png_voidp argument) +@@ -3678,6 +3726,7 @@ png_image_read_direct(png_voidp argument) + int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0; + int do_local_compose = 0; + int do_local_background = 0; /* to avoid double gamma correction bug */ ++ int do_local_scale = 0; /* for interlaced 16-to-8 bit conversion */ + int passes = 0; + + /* Add transforms to ensure the correct output format is produced then check +@@ -3804,8 +3853,16 @@ png_image_read_direct(png_voidp argument) + png_set_expand_16(png_ptr); + + else /* 8-bit output */ ++ { + png_set_scale_16(png_ptr); + ++ /* For interlaced images, use local_row buffer to avoid overflow ++ * in png_combine_row() which writes using IHDR bit-depth. ++ */ ++ if (png_ptr->interlaced != 0) ++ do_local_scale = 1; ++ } ++ + change &= ~PNG_FORMAT_FLAG_LINEAR; + } + +@@ -4081,6 +4138,24 @@ png_image_read_direct(png_voidp argument) + return result; + } + ++ else if (do_local_scale != 0) ++ { ++ /* For interlaced 16-to-8 conversion, use an intermediate row buffer ++ * to avoid buffer overflows in png_combine_row. The local_row is sized ++ * for the transformed (8-bit) output, preventing the overflow that would ++ * occur if png_combine_row wrote 16-bit data directly to the user buffer. ++ */ ++ int result; ++ png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); ++ ++ display->local_row = row; ++ result = png_safe_execute(image, png_image_read_direct_scaled, display); ++ display->local_row = NULL; ++ png_free(png_ptr, row); ++ ++ return result; ++ } ++ + else + { + png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes; +@@ -4164,20 +4239,6 @@ png_image_finish_read(png_imagep image, png_const_colorp background, + int result; + png_image_read_control display; + +- /* Reject bit depth mismatches to avoid buffer overflows. */ +- png_uint_32 ihdr_bit_depth = +- image->opaque->png_ptr->bit_depth; +- int requested_linear = +- (image->format & PNG_FORMAT_FLAG_LINEAR) != 0; +- if (ihdr_bit_depth == 16 && !requested_linear) +- return png_image_error(image, +- "png_image_finish_read: " +- "16-bit PNG must use 16-bit output format"); +- if (ihdr_bit_depth < 16 && requested_linear) +- return png_image_error(image, +- "png_image_finish_read: " +- "8-bit PNG must not use 16-bit output format"); +- + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; diff --git a/meta/recipes-multimedia/libpng/libpng_1.6.39.bb b/meta/recipes-multimedia/libpng/libpng_1.6.39.bb index efb8eba3721..47b76a704b8 100644 --- a/meta/recipes-multimedia/libpng/libpng_1.6.39.bb +++ b/meta/recipes-multimedia/libpng/libpng_1.6.39.bb @@ -18,6 +18,8 @@ SRC_URI = "\ file://CVE-2025-64505-03.patch \ file://CVE-2025-64506.patch \ file://CVE-2025-64720.patch \ + file://CVE-2025-65018-01.patch \ + file://CVE-2025-65018-02.patch \ " SRC_URI[sha256sum] = "1f4696ce70b4ee5f85f1e1623dc1229b210029fa4b7aee573df3e2ba7b036937"