File 0015-video-readers-png-Sanity-check-some-huffman-codes.patch of Package grub2.24428
From ccd841fa099fb94ba06322d4e179de6775a5868f Mon Sep 17 00:00:00 2001 From: Daniel Axtens <dja@axtens.net> Date: Tue, 6 Jul 2021 19:19:11 +1000 Subject: [PATCH 15/33] video/readers/png: Sanity check some huffman codes ASAN picked up two OOB global reads: we weren't checking if some code values fit within the cplens or cpdext arrays. Check and throw an error if not. Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> --- grub-core/video/readers/png.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c index 24e972d1ba..6c37678c40 100644 --- a/grub-core/video/readers/png.c +++ b/grub-core/video/readers/png.c @@ -753,6 +753,9 @@ grub_png_read_dynamic_block (struct grub_png_data *data) int len, dist, pos; n -= 257; + if (((unsigned int) n) >= ARRAY_SIZE (cplens)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: invalid huff code"); len = cplens[n]; if (cplext[n]) len += grub_png_get_bits (data, cplext[n]); @@ -760,6 +763,9 @@ grub_png_read_dynamic_block (struct grub_png_data *data) return grub_errno; n = grub_png_get_huff_code (data, &data->dist_table); + if (((unsigned int) n) >= ARRAY_SIZE (cpdist)) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, + "png: invalid huff code"); dist = cpdist[n]; if (cpdext[n]) dist += grub_png_get_bits (data, cpdext[n]); -- 2.34.1
