hush: fix potential buffer overflow on NOMMU

[oweals/busybox.git] / coreutils / cksum.c

diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index 987f5f32c76824fffd23df28282b67ddc362f7c3..8e65b1ca3b35b84093056c74857cd0eaaade6018 100644 (file)
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -4,51 +4,64 @@
  *
  * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */
-
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
 #include "libbb.h"
 
-int cksum_main(int argc, char **argv);
-int cksum_main(int argc, char **argv)
+int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int cksum_main(int argc UNUSED_PARAM, char **argv)
 {
        uint32_t *crc32_table = crc32_filltable(NULL, 1);
-
-       FILE *fp;
        uint32_t crc;
-       long length, filesize;
+       off_t length, filesize;
        int bytes_read;
-       char *cp;
+       int exit_code = EXIT_SUCCESS;
+       uint8_t *cp;
 
-       int inp_stdin = (argc == optind) ? 1 : 0;
+#if ENABLE_DESKTOP
+       getopt32(argv, ""); /* coreutils 6.9 compat */
+       argv += optind;
+#else
+       argv++;
+#endif
 
        do {
-               fp = fopen_or_warn_stdin((inp_stdin) ? bb_msg_standard_input : *++argv);
+               int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
 
+               if (fd < 0) {
+                       exit_code = EXIT_FAILURE;
+                       continue;
+               }
                crc = 0;
                length = 0;
 
 #define read_buf bb_common_bufsiz1
-               while ((bytes_read = fread(read_buf, 1, BUFSIZ, fp)) > 0) {
-                       cp = read_buf;
+               while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
+                       cp = (uint8_t *) read_buf;
                        length += bytes_read;
-                       while (bytes_read--)
-                               crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
+                       do {
+                               crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
+                       } while (--bytes_read);
                }
+               close(fd);
 
                filesize = length;
 
-               for (; length; length >>= 8)
-                       crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
-               crc ^= 0xffffffffL;
-
-               if (inp_stdin) {
-                       printf("%" PRIu32 " %li\n", crc, filesize);
-                       break;
+               while (length) {
+                       crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
+                       /* must ensure that shift is unsigned! */
+                       if (sizeof(length) <= sizeof(unsigned))
+                               length = (unsigned)length >> 8;
+                       else if (sizeof(length) <= sizeof(unsigned long))
+                               length = (unsigned long)length >> 8;
+                       else
+                               length = (unsigned long long)length >> 8;
                }
+               crc = ~crc;
 
-               printf("%" PRIu32 " %li %s\n", crc, filesize, *argv);
-               fclose(fp);
-       } while (*(argv + 1));
+               printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
+                               crc, filesize, *argv);
+       } while (*argv && *++argv);
 
-       fflush_stdout_and_exit(EXIT_SUCCESS);
+       fflush_stdout_and_exit(exit_code);
 }