view src/xpm_w32.c @ 33422:25d250a74bb6 v9.0.1969

patch 9.0.1969: [security] buffer-overflow in trunc_string() Commit: https://github.com/vim/vim/commit/3bd7fa12e146c6051490d048a4acbfba974eeb04 Author: Christian Brabandt <cb@256bit.org> Date: Mon Oct 2 20:59:08 2023 +0200 patch 9.0.1969: [security] buffer-overflow in trunc_string() Problem: buffer-overflow in trunc_string() Solution: Add NULL at end of buffer Currently trunc_string() assumes that when the string is too long, buf[e-1] will always be writeable. But that assumption may not always be true. The condition currently looks like this else if (e + 3 < buflen) [...] else { // can't fit in the "...", just truncate it buf[e - 1] = NUL; } but this means, we may run into the last else clause with e still being larger than buflen. So a buffer overflow occurs. So instead of using `buf[e - 1]`, let's just always truncate at `buf[buflen - 1]` which should always be writable. Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Mon, 02 Oct 2023 21:30:04 +0200
parents 15539899a112
children
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/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * Load XPM image.
 *
 * This function is placed in separate file because Xpm headers conflict with
 * Vim ones :(
 *
 * Written by Sergey Khorev.
 * http://iamphet.nm.ru/vim/index.html
 */

#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>

#include "xpm_w32.h"

// Engage Windows support in libXpm
#define FOR_MSW

#include "xpm.h"

/*
 * Tries to load an Xpm image from the file "filename".
 * Returns -1 on failure.
 * Returns 0 on success and stores image and mask BITMAPS in "hImage" and
 * "hShape".
 */
    int
LoadXpmImage(
    char    *filename,
    HBITMAP *hImage,
    HBITMAP *hShape)
{
    XImage	    *img;  // loaded image
    XImage	    *shp;  // shapeimage
    XpmAttributes   attr;
    int		    res;
    HDC		    hdc = CreateCompatibleDC(NULL);

    attr.valuemask = 0;
    res = XpmReadFileToImage(&hdc, filename, &img, &shp, &attr);
    DeleteDC(hdc);
    if (res < 0)
	return -1;
    if (shp == NULL)
    {
	if (img)
	    XDestroyImage(img);
	return -1;
    }
    *hImage = img->bitmap;
    *hShape = shp->bitmap;
    return 0;
}