From e170edd18fcfdd9e6f91ba750fd022cef8d43cd4 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Tue, 6 Jul 2021 14:13:40 +1000 Subject: [PATCH] video/readers/png: Refuse to handle multiple image headers This causes the bitmap to be leaked. Do not permit multiple image headers. Signed-off-by: Daniel Axtens Reviewed-by: Daniel Kiper Upstream: 166a4d61448f74745afe1dac2f2cfb85d04909bf [Thomas: needed to cherry-pick e623866d9286410156e8b9d2c82d6253a1b22d08, which fixes CVE-2021-3695] Signed-off-by: Thomas Petazzoni --- grub-core/video/readers/png.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c index d715c4629..35ae553c8 100644 --- a/grub-core/video/readers/png.c +++ b/grub-core/video/readers/png.c @@ -258,6 +258,9 @@ grub_png_decode_image_header (struct grub_png_data *data) int color_bits; enum grub_video_blit_format blt; + if (data->image_width || data->image_height) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: two image headers found"); + data->image_width = grub_png_get_dword (data); data->image_height = grub_png_get_dword (data); -- 2.41.0