From 06d326d3a6e343dd5df992afcd3613ea2188d28a Mon Sep 17 00:00:00 2001 From: Jon Smith Date: Thu, 5 Oct 2017 08:35:02 -0400 Subject: [PATCH] tools: bmp_logo: correctly interpret BMP files with larger headers All BMP files were being treated as though they had a 40 byte header. There are several BMP header formats consisting of additional data. This was causing some of the header to be read as color information, skewing the color palette. Signed-off-by: Jon Smith --- tools/bmp_logo.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/bmp_logo.c b/tools/bmp_logo.c index 2247adcc82..55f833fb9b 100644 --- a/tools/bmp_logo.c +++ b/tools/bmp_logo.c @@ -76,7 +76,7 @@ int main (int argc, char *argv[]) FILE *fp; bitmap_t bmp; bitmap_t *b = &bmp; - uint16_t data_offset, n_colors; + uint16_t data_offset, n_colors, hdr_size; if (argc < 3) { usage(argv[0]); @@ -108,7 +108,12 @@ int main (int argc, char *argv[]) skip_bytes (fp, 8); if (fread (&data_offset, sizeof (uint16_t), 1, fp) != 1) error ("Couldn't read bitmap data offset", fp); - skip_bytes (fp, 6); + skip_bytes(fp, 2); + if (fread(&hdr_size, sizeof(uint16_t), 1, fp) != 1) + error("Couldn't read bitmap header size", fp); + if (hdr_size < 40) + error("Invalid bitmap header", fp); + skip_bytes(fp, 2); if (fread (&b->width, sizeof (uint16_t), 1, fp) != 1) error ("Couldn't read bitmap width", fp); skip_bytes (fp, 2); @@ -117,7 +122,7 @@ int main (int argc, char *argv[]) skip_bytes (fp, 22); if (fread (&n_colors, sizeof (uint16_t), 1, fp) != 1) error ("Couldn't read bitmap colors", fp); - skip_bytes (fp, 6); + skip_bytes(fp, hdr_size - 34); /* * Repair endianess. -- 2.25.1