1 /* 2 * Check decoding of process_vm_readv/process_vm_writev syscall. 3 * 4 * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr (at) gmail.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <inttypes.h> 31 #include <stdio.h> 32 #include <unistd.h> 33 #include <sys/uio.h> 34 35 #if OP_WR 36 # define in_iovec rmt_iovec 37 # define out_iovec lcl_iovec 38 # define in_iov rmt_iov 39 # define out_iov lcl_iov 40 #else 41 # define in_iovec lcl_iovec 42 # define out_iovec rmt_iovec 43 # define in_iov lcl_iov 44 # define out_iov rmt_iov 45 #endif 46 47 typedef void (*iov_print_fn)(const struct iovec *, const void *, long); 48 49 enum { MAX_SEGM_COUNT = 2, MAX_STR_LEN = 5 }; 50 51 struct print_iov_arg { 52 uint32_t count; 53 uint32_t valid :1, 54 string :1, 55 addr_term:1, 56 check_rc :1; 57 uint32_t str_segms; 58 uint8_t str_base[MAX_SEGM_COUNT]; 59 uint8_t str_size[MAX_SEGM_COUNT]; 60 }; 61 62 static void 63 print_iov(const struct iovec *iov, const void *arg_ptr, long rc) 64 { 65 const struct print_iov_arg *arg = arg_ptr; 66 uint32_t i; 67 uint32_t num_segm = 0; 68 uint64_t segm_offs = 0; 69 70 if (!arg || !arg->valid) { 71 if (iov) 72 printf("%p", iov); 73 else 74 printf("NULL"); 75 76 return; 77 } 78 79 printf("["); 80 81 for (i = 0; i < arg->count; i++) { 82 if (i) 83 printf(", "); 84 85 if (i >= MAX_STR_LEN) { 86 printf("..."); 87 break; 88 } 89 90 printf("{iov_base="); 91 if (arg->string && (!arg->check_rc || (rc != -1))) { 92 uint64_t str_left = iov[i].iov_len; 93 uint64_t pr_count = 0; 94 95 printf("\""); 96 97 while (str_left--) { 98 static const char oct_str[] = "01234567"; 99 uint8_t c = arg->str_base[num_segm] + segm_offs; 100 101 if ((num_segm >= arg->str_segms) || 102 (num_segm >= MAX_SEGM_COUNT)) 103 error_msg_and_fail("print_iov: segment " 104 "count overrun"); 105 106 if (pr_count++ < MAX_STR_LEN) 107 printf("\\%.1s%.1s%d", 108 (c >> 6) ? 109 oct_str + (c >> 6) : "", 110 (c >> 3) ? 111 oct_str + ((c >> 3) & 7) : "", 112 c & 7); 113 114 segm_offs++; 115 116 if (segm_offs >= arg->str_size[num_segm]) { 117 num_segm++; 118 segm_offs = 0; 119 } 120 } 121 122 printf("\""); 123 124 if (pr_count > MAX_STR_LEN) 125 printf("..."); 126 } else { 127 if (iov[i].iov_base) 128 printf("%p", iov[i].iov_base); 129 else 130 printf("NULL"); 131 } 132 133 printf(", iov_len=%zu}", iov[i].iov_len); 134 } 135 136 if (arg->addr_term) 137 printf(", %p", iov + arg->count); 138 139 printf("]"); 140 } 141 142 static void 143 do_call(kernel_ulong_t pid, 144 kernel_ulong_t local_iov, const char *local_arg, 145 kernel_ulong_t liovcnt, 146 kernel_ulong_t remote_iov, const char *remote_arg, 147 kernel_ulong_t riovcnt, 148 kernel_ulong_t flags, iov_print_fn pr_iov) 149 { 150 long rc; 151 const char *errstr; 152 153 rc = syscall(OP_NR, pid, local_iov, liovcnt, remote_iov, riovcnt, 154 flags); 155 errstr = sprintrc(rc); 156 157 printf("%s(%d, ", OP_STR, (int) pid); 158 159 if (pr_iov) 160 pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg, 161 rc); 162 else 163 printf("%s", local_arg); 164 165 printf(", %lu, ", (unsigned long) liovcnt); 166 167 if (pr_iov) 168 pr_iov((const struct iovec *) (uintptr_t) remote_iov, 169 remote_arg, rc); 170 else 171 printf("%s", remote_arg); 172 173 printf(", %lu, %lu) = %s\n", (unsigned long) riovcnt, 174 (unsigned long) flags, errstr); 175 } 176 177 kernel_ulong_t 178 ptr_cast(void *ptr) 179 { 180 return (kernel_ulong_t) (uintptr_t) ptr; 181 } 182 183 int 184 main(void) 185 { 186 enum { 187 SIZE_11 = 2, 188 SIZE_12 = 3, 189 SIZE_13 = 4, 190 SIZE_1 = SIZE_11 + SIZE_12 + SIZE_13, 191 SIZE_21 = 5, 192 SIZE_22 = 6, 193 SIZE_23 = 7, 194 SIZE_2 = SIZE_21 + SIZE_22 + SIZE_23, 195 }; 196 197 enum { 198 SEGM1_BASE = 0x80, 199 SEGM2_BASE = 0xA0, 200 }; 201 202 static const kernel_ulong_t bogus_pid = 203 (kernel_ulong_t) 0xbadfaceddeadca57ULL; 204 static const kernel_ulong_t bogus_iovcnt1 = 205 (kernel_ulong_t) 0xdec0ded1defaced2ULL; 206 static const kernel_ulong_t bogus_iovcnt2 = 207 (kernel_ulong_t) 0xdec0ded3defaced4ULL; 208 static const kernel_ulong_t bogus_flags = 209 (kernel_ulong_t) 0xdeadc0deda7adeadULL; 210 211 pid_t my_pid = getpid(); 212 char *data1_out = tail_alloc(SIZE_1); 213 char *data2_out = tail_alloc(SIZE_2); 214 char *data1_in = tail_alloc(SIZE_2); 215 char *data2_in = tail_alloc(SIZE_1); 216 217 struct iovec bogus_iovec[] = { 218 { data1_out + SIZE_1, (size_t) 0xdeadfaceca57beefULL }, 219 { data1_in + SIZE_2, (size_t) 0xbadc0dedda7adeadULL }, 220 { data2_out + SIZE_2, (size_t) 0xf157facedec0ded1ULL }, 221 { data2_in + SIZE_1, (size_t) 0xdefaced2bea7be57ULL }, 222 }; 223 224 struct iovec out_iovec[] = { 225 { data1_out, SIZE_11 }, 226 { data1_out + SIZE_11, SIZE_12 }, 227 { data1_out + SIZE_11 + SIZE_12, SIZE_13 }, 228 { data2_out, SIZE_21 }, 229 { data2_out + SIZE_21, SIZE_22 }, 230 { data2_out + SIZE_21 + SIZE_22, SIZE_23 }, 231 }; 232 struct iovec in_iovec[] = { 233 { data1_in, SIZE_23 }, 234 { data1_in + SIZE_23, SIZE_22 }, 235 { data1_in + SIZE_23 + SIZE_22, SIZE_21 }, 236 { data2_in, SIZE_13 }, 237 { data2_in + SIZE_13, SIZE_12 }, 238 { data2_in + SIZE_13 + SIZE_12, SIZE_11 }, 239 }; 240 241 struct iovec *bogus_iov = tail_memdup(bogus_iovec, sizeof(bogus_iovec)); 242 struct iovec *lcl_iov = tail_memdup(lcl_iovec, sizeof(lcl_iovec)); 243 struct iovec *rmt_iov = tail_memdup(rmt_iovec, sizeof(rmt_iovec)); 244 245 struct print_iov_arg bogus_arg = { ARRAY_SIZE(bogus_iovec), 1 }; 246 struct print_iov_arg lcl_arg = { ARRAY_SIZE(lcl_iovec), 1, 1, 0, 0, 247 2, {SEGM1_BASE, SEGM2_BASE}, {SIZE_1, SIZE_2} }; 248 struct print_iov_arg rmt_arg = { ARRAY_SIZE(rmt_iovec), 1 }; 249 250 struct print_iov_arg bogus_arg_cut = { 251 ARRAY_SIZE(bogus_iovec) - 2, 1, 0, 1 252 }; 253 struct print_iov_arg lcl_arg_cut = { 254 ARRAY_SIZE(lcl_iovec) - 2, 1, 1, 1, 0, 2, 255 { SEGM1_BASE + SIZE_11 + SIZE_12, SEGM2_BASE }, 256 {SIZE_13, SIZE_2} 257 }; 258 struct print_iov_arg rmt_arg_cut = { ARRAY_SIZE(rmt_iovec) - 2, 1 }; 259 260 261 fill_memory_ex(data1_out, SIZE_1, SEGM1_BASE, SIZE_1); 262 fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2); 263 264 265 do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL), 266 bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL), 267 bogus_iovcnt2, bogus_flags, NULL); 268 269 do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), 270 "[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]", 271 0, 0, NULL); 272 do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL, 273 bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL, 274 bogus_iovcnt2, 0, print_iov); 275 276 do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg, 277 ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2), 278 (char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov); 279 280 #if !OP_WR 281 lcl_arg.check_rc = 1; 282 lcl_arg_cut.check_rc = 1; 283 #endif 284 285 do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut, 286 ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2), 287 (char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0, 288 print_iov); 289 290 lcl_arg_cut.addr_term = 0; 291 292 rmt_arg_cut.addr_term = 1; 293 rmt_arg_cut.count = 5; 294 295 do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut, 296 ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1), 297 (char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov); 298 299 /* Correct call */ 300 do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg, 301 ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg, 302 ARRAY_SIZE(rmt_iovec), 0, print_iov); 303 304 puts("+++ exited with 0 +++"); 305 306 return 0; 307 } 308
