cafe-grader-judge-scripts

Commit r76:4469d653fe5f public

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Description:
added /dev/urandom to file allowed to be accessed, probably needed after ubuntu 9.04 git-svn-id: http://theory.cpe.ku.ac.th/grader/judge/trunk/scripts@417 6386c4cd-e34a-4fa8-8920-d93eb39b512e
Commit status:
[Not Reviewed]
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r76:4469d653fe5f - - 1 file changed: 1 inserted, 0 deleted

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@@ -142,96 +142,97
142 if (file_access >= 9)
142 if (file_access >= 9)
143 return;
143 return;
144
144
145 if (!mem_fd)
145 if (!mem_fd)
146 {
146 {
147 sprintf(namebuf, "/proc/%d/mem", (int) box_pid);
147 sprintf(namebuf, "/proc/%d/mem", (int) box_pid);
148 mem_fd = open(namebuf, O_RDONLY);
148 mem_fd = open(namebuf, O_RDONLY);
149 if (mem_fd < 0)
149 if (mem_fd < 0)
150 die("open(%s): %m", namebuf);
150 die("open(%s): %m", namebuf);
151 }
151 }
152 p = end = namebuf;
152 p = end = namebuf;
153 do
153 do
154 {
154 {
155 if (p >= end)
155 if (p >= end)
156 {
156 {
157 int remains = PAGE_SIZE - (addr & (PAGE_SIZE-1));
157 int remains = PAGE_SIZE - (addr & (PAGE_SIZE-1));
158 int l = namebuf + sizeof(namebuf) - end;
158 int l = namebuf + sizeof(namebuf) - end;
159 if (l > remains)
159 if (l > remains)
160 l = remains;
160 l = remains;
161 if (!l)
161 if (!l)
162 die("Access to file with name too long.");
162 die("Access to file with name too long.");
163 if (long_seek(mem_fd, addr, SEEK_SET) < 0)
163 if (long_seek(mem_fd, addr, SEEK_SET) < 0)
164 die("long_seek(mem): %m");
164 die("long_seek(mem): %m");
165 remains = read(mem_fd, end, l);
165 remains = read(mem_fd, end, l);
166 if (remains < 0)
166 if (remains < 0)
167 die("read(mem): %m");
167 die("read(mem): %m");
168 if (!remains)
168 if (!remains)
169 die("Access to file with name out of memory.");
169 die("Access to file with name out of memory.");
170 end += l;
170 end += l;
171 addr += l;
171 addr += l;
172 }
172 }
173 }
173 }
174 while (*p++);
174 while (*p++);
175
175
176 log("[%s] ", namebuf);
176 log("[%s] ", namebuf);
177 if (file_access >= 3)
177 if (file_access >= 3)
178 return;
178 return;
179 if (!strchr(namebuf, '/') && strcmp(namebuf, ".."))
179 if (!strchr(namebuf, '/') && strcmp(namebuf, ".."))
180 return;
180 return;
181 if (file_access >= 2)
181 if (file_access >= 2)
182 {
182 {
183 if ((!strncmp(namebuf, "/etc/", 5) ||
183 if ((!strncmp(namebuf, "/etc/", 5) ||
184 !strncmp(namebuf, "/lib/", 5) ||
184 !strncmp(namebuf, "/lib/", 5) ||
185 !strncmp(namebuf, "/usr/lib/", 9))
185 !strncmp(namebuf, "/usr/lib/", 9))
186 && !strstr(namebuf, ".."))
186 && !strstr(namebuf, ".."))
187 return;
187 return;
188 if (!strcmp(namebuf, "/dev/null") ||
188 if (!strcmp(namebuf, "/dev/null") ||
189 !strcmp(namebuf, "/dev/zero") ||
189 !strcmp(namebuf, "/dev/zero") ||
190 + !strcmp(namebuf, "/dev/urandom") ||
190 !strcmp(namebuf, "/proc/meminfo") ||
191 !strcmp(namebuf, "/proc/meminfo") ||
191 !strcmp(namebuf, "/proc/self/stat") ||
192 !strcmp(namebuf, "/proc/self/stat") ||
192 !strncmp(namebuf, "/usr/share/zoneinfo/", 20))
193 !strncmp(namebuf, "/usr/share/zoneinfo/", 20))
193 return;
194 return;
194 }
195 }
195 die("Forbidden access to file `%s'.", namebuf);
196 die("Forbidden access to file `%s'.", namebuf);
196 }
197 }
197
198
198 static int
199 static int
199 valid_syscall(struct user *u)
200 valid_syscall(struct user *u)
200 {
201 {
201 switch (u->regs.orig_eax)
202 switch (u->regs.orig_eax)
202 {
203 {
203 case __NR_execve:
204 case __NR_execve:
204 {
205 {
205 static int exec_counter;
206 static int exec_counter;
206 return !exec_counter++;
207 return !exec_counter++;
207 }
208 }
208 case __NR_open:
209 case __NR_open:
209 case __NR_creat:
210 case __NR_creat:
210 case __NR_unlink:
211 case __NR_unlink:
211 case __NR_oldstat:
212 case __NR_oldstat:
212 case __NR_access:
213 case __NR_access:
213 case __NR_oldlstat:
214 case __NR_oldlstat:
214 case __NR_truncate:
215 case __NR_truncate:
215 case __NR_stat:
216 case __NR_stat:
216 case __NR_lstat:
217 case __NR_lstat:
217 case __NR_truncate64:
218 case __NR_truncate64:
218 case __NR_stat64:
219 case __NR_stat64:
219 case __NR_lstat64:
220 case __NR_lstat64:
220 valid_filename(u->regs.ebx);
221 valid_filename(u->regs.ebx);
221 return 1;
222 return 1;
222 case __NR_exit:
223 case __NR_exit:
223 case __NR_read:
224 case __NR_read:
224 case __NR_write:
225 case __NR_write:
225 case __NR_close:
226 case __NR_close:
226 case __NR_lseek:
227 case __NR_lseek:
227 case __NR_getpid:
228 case __NR_getpid:
228 case __NR_getuid:
229 case __NR_getuid:
229 case __NR_oldfstat:
230 case __NR_oldfstat:
230 case __NR_dup:
231 case __NR_dup:
231 case __NR_brk:
232 case __NR_brk:
232 case __NR_getgid:
233 case __NR_getgid:
233 case __NR_geteuid:
234 case __NR_geteuid:
234 case __NR_getegid:
235 case __NR_getegid:
235 case __NR_dup2:
236 case __NR_dup2:
236 case __NR_ftruncate:
237 case __NR_ftruncate:
237 case __NR_fstat:
238 case __NR_fstat:
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