1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
$NetBSD: patch-af,v 1.2 2005/06/14 18:10:37 jlam Exp $
--- lib/CrDatFrI.c.orig 1998-03-19 14:50:59.000000000 -0500
+++ lib/CrDatFrI.c
@@ -32,13 +32,16 @@
* Developed by Arnaud Le Hors *
\*****************************************************************************/
+/* October 2004, source code review by Thomas Biege <thomas@suse.de> */
+
#include "XpmI.h"
LFUNC(CreateColors, int, (char **dataptr, unsigned int *data_size,
XpmColor *colors, unsigned int ncolors,
unsigned int cpp));
-LFUNC(CreatePixels, void, (char **dataptr, unsigned int width,
+LFUNC(CreatePixels, void, (char **dataptr, unsigned int data_size,
+ unsigned int width,
unsigned int height, unsigned int cpp,
unsigned int *pixels, XpmColor *colors));
@@ -46,7 +49,8 @@ LFUNC(CountExtensions, void, (XpmExtensi
unsigned int *ext_size,
unsigned int *ext_nlines));
-LFUNC(CreateExtensions, void, (char **dataptr, unsigned int offset,
+LFUNC(CreateExtensions, void, (char **dataptr, unsigned int data_size,
+ unsigned int offset,
XpmExtension *ext, unsigned int num,
unsigned int ext_nlines));
@@ -87,10 +91,11 @@ XpmCreateDataFromImage(display, data_ret
#undef RETURN
#define RETURN(status) \
+do \
{ \
ErrorStatus = status; \
goto exit; \
-}
+} while(0)
int
XpmCreateDataFromXpmImage(data_return, image, info)
@@ -121,9 +126,17 @@ XpmCreateDataFromXpmImage(data_return, i
* alloc a temporary array of char pointer for the header section which
* is the hints line + the color table lines
*/
- header_nlines = 1 + image->ncolors;
+ header_nlines = 1 + image->ncolors; /* this may wrap and/or become 0 */
+
+ /* 2nd check superfluous if we do not need header_nlines any further */
+ if(header_nlines <= image->ncolors ||
+ header_nlines >= UINT_MAX / sizeof(char *))
+ return(XpmNoMemory);
+
header_size = sizeof(char *) * header_nlines;
- header = (char **) XpmCalloc(header_size, sizeof(char *));
+ if (header_size >= UINT_MAX / sizeof(char *))
+ return (XpmNoMemory);
+ header = (char **) XpmCalloc(header_size, sizeof(char *)); /* can we trust image->ncolors */
if (!header)
return (XpmNoMemory);
@@ -167,8 +180,22 @@ XpmCreateDataFromXpmImage(data_return, i
/* now we know the size needed, alloc the data and copy the header lines */
offset = image->width * image->cpp + 1;
- data_size = header_size + (image->height + ext_nlines) * sizeof(char *)
- + image->height * offset + ext_size;
+
+ if(offset <= image->width || offset <= image->cpp)
+ RETURN(XpmNoMemory);
+
+ if( (image->height + ext_nlines) >= UINT_MAX / sizeof(char *))
+ RETURN(XpmNoMemory);
+ data_size = (image->height + ext_nlines) * sizeof(char *);
+
+ if (image->height > UINT_MAX / offset ||
+ image->height * offset > UINT_MAX - data_size)
+ RETURN(XpmNoMemory);
+ data_size += image->height * offset;
+
+ if( (header_size + ext_size) >= (UINT_MAX - data_size) )
+ RETURN(XpmNoMemory);
+ data_size += header_size + ext_size;
data = (char **) XpmMalloc(data_size);
if (!data)
@@ -176,8 +203,10 @@ XpmCreateDataFromXpmImage(data_return, i
data_nlines = header_nlines + image->height + ext_nlines;
*data = (char *) (data + data_nlines);
+
+ /* can header have less elements then n suggests? */
n = image->ncolors;
- for (l = 0, sptr = data, sptr2 = header; l <= n; l++, sptr++, sptr2++) {
+ for (l = 0, sptr = data, sptr2 = header; l <= n && sptr && sptr2; l++, sptr++, sptr2++) {
strcpy(*sptr, *sptr2);
*(sptr + 1) = *sptr + strlen(*sptr2) + 1;
}
@@ -186,12 +215,13 @@ XpmCreateDataFromXpmImage(data_return, i
data[header_nlines] = (char *) data + header_size
+ (image->height + ext_nlines) * sizeof(char *);
- CreatePixels(data + header_nlines, image->width, image->height,
+ CreatePixels(data + header_nlines, data_size-header_nlines, image->width, image->height,
image->cpp, image->data, image->colorTable);
/* print extensions */
if (extensions)
- CreateExtensions(data + header_nlines + image->height - 1, offset,
+ CreateExtensions(data + header_nlines + image->height - 1,
+ data_size - header_nlines - image->height + 1, offset,
info->extensions, info->nextensions,
ext_nlines);
@@ -222,23 +252,35 @@ CreateColors(dataptr, data_size, colors,
char *s, *s2;
char **defaults;
+ /* can ncolors be trusted here? */
for (a = 0; a < ncolors; a++, colors++, dataptr++) {
defaults = (char **) colors;
+ if(sizeof(buf) <= cpp)
+ return(XpmNoMemory);
strncpy(buf, *defaults++, cpp);
s = buf + cpp;
+ if(sizeof(buf) <= (s-buf))
+ return XpmNoMemory;
+
for (key = 1; key <= NKEYS; key++, defaults++) {
if (s2 = *defaults) {
#ifndef VOID_SPRINTF
s +=
#endif
- sprintf(s, "\t%s %s", xpmColorKeys[key - 1], s2);
+ /* assume C99 compliance */
+ snprintf(s, sizeof(buf)-(s-buf), "\t%s %s", xpmColorKeys[key - 1], s2);
+
#ifdef VOID_SPRINTF
s += strlen(s);
#endif
+ /* does s point out-of-bounds? */
+ if(sizeof(buf) < (s-buf))
+ return XpmNoMemory;
}
}
+ /* what about using strdup()? */
l = s - buf + 1;
s = (char *) XpmMalloc(l);
if (!s)
@@ -250,8 +292,9 @@ CreateColors(dataptr, data_size, colors,
}
static void
-CreatePixels(dataptr, width, height, cpp, pixels, colors)
+CreatePixels(dataptr, data_size, width, height, cpp, pixels, colors)
char **dataptr;
+ unsigned int data_size;
unsigned int width;
unsigned int height;
unsigned int cpp;
@@ -261,21 +304,38 @@ CreatePixels(dataptr, width, height, cpp
char *s;
unsigned int x, y, h, offset;
+ if(height <= 1)
+ return;
+
h = height - 1;
+
offset = width * cpp + 1;
+
+ if(offset <= width || offset <= cpp)
+ return;
+
+ /* why trust h? */
for (y = 0; y < h; y++, dataptr++) {
s = *dataptr;
+ /* why trust width? */
for (x = 0; x < width; x++, pixels++) {
- strncpy(s, colors[*pixels].string, cpp);
+ if(cpp > (data_size - (s - *dataptr)))
+ return;
+ strncpy(s, colors[*pixels].string, cpp); /* why trust pixel? */
s += cpp;
}
*s = '\0';
+ if(offset > data_size)
+ return;
*(dataptr + 1) = *dataptr + offset;
}
/* duplicate some code to avoid a test in the loop */
s = *dataptr;
+ /* why trust width? */
for (x = 0; x < width; x++, pixels++) {
- strncpy(s, colors[*pixels].string, cpp);
+ if(cpp > data_size - (s - *dataptr))
+ return;
+ strncpy(s, colors[*pixels].string, cpp); /* why should we trust *pixel? */
s += cpp;
}
*s = '\0';
@@ -308,8 +368,9 @@ CountExtensions(ext, num, ext_size, ext_
}
static void
-CreateExtensions(dataptr, offset, ext, num, ext_nlines)
+CreateExtensions(dataptr, data_size, offset, ext, num, ext_nlines)
char **dataptr;
+ unsigned int data_size;
unsigned int offset;
XpmExtension *ext;
unsigned int num;
@@ -322,12 +383,12 @@ CreateExtensions(dataptr, offset, ext, n
dataptr++;
a = 0;
for (x = 0; x < num; x++, ext++) {
- sprintf(*dataptr, "XPMEXT %s", ext->name);
+ snprintf(*dataptr, data_size, "XPMEXT %s", ext->name);
a++;
if (a < ext_nlines)
*(dataptr + 1) = *dataptr + strlen(ext->name) + 8;
dataptr++;
- b = ext->nlines;
+ b = ext->nlines; /* can we trust these values? */
for (y = 0, line = ext->lines; y < b; y++, line++) {
strcpy(*dataptr, *line);
a++;
|
