kwo pushed a commit to branch master. http://git.enlightenment.org/legacy/imlib2.git/commit/?id=07deb8c8932d59a138bc42cef7979cdab88dce6e
commit 07deb8c8932d59a138bc42cef7979cdab88dce6e Author: Kim Woelders <[email protected]> Date: Thu Sep 30 13:12:37 2021 +0200 PNG loader: Use mmap() during signature check --- src/modules/loaders/loader_png.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/src/modules/loaders/loader_png.c b/src/modules/loaders/loader_png.c index 5f48a7b..d8fd3a4 100644 --- a/src/modules/loaders/loader_png.c +++ b/src/modules/loaders/loader_png.c @@ -1,5 +1,7 @@ #include "loader_common.h" + #include <png.h> +#include <sys/mman.h> /* this is a quick sample png loader module... nice and small isn't it? */ @@ -7,7 +9,6 @@ #define PNG_BYTES_TO_CHECK 4 typedef struct { - unsigned char buf[PNG_BYTES_TO_CHECK]; unsigned char **lines; } ImLib_PNG_data; @@ -20,7 +21,8 @@ comment_free(ImlibImage * im, void *data) int load2(ImlibImage * im, int load_data) { - int rc; + int rc, ok; + void *fdata; png_uint_32 w32, h32; char hasa; png_structp png_ptr = NULL; @@ -33,13 +35,20 @@ load2(ImlibImage * im, int load_data) rc = LOAD_FAIL; pdata.lines = NULL; - if (fread(pdata.buf, 1, PNG_BYTES_TO_CHECK, im->fp) != PNG_BYTES_TO_CHECK) - goto quit; + if (im->fsize < PNG_BYTES_TO_CHECK) + return rc; - if (png_sig_cmp(pdata.buf, 0, PNG_BYTES_TO_CHECK)) - goto quit; + fdata = + mmap(NULL, PNG_BYTES_TO_CHECK, PROT_READ, MAP_SHARED, fileno(im->fp), 0); + if (fdata == MAP_FAILED) + return rc; + + ok = png_sig_cmp(fdata, 0, PNG_BYTES_TO_CHECK) == 0; + + munmap(fdata, PNG_BYTES_TO_CHECK); - rewind(im->fp); + if (!ok) + return rc; png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) --
