tar: abort if tarring up file larger that 64Gb
(otherwise we will produce garbled tarfile)
diff --git a/archival/tar.c b/archival/tar.c
index b326d1e..d875805 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -150,40 +150,29 @@
/* Put an octal string into the specified buffer.
* The number is zero padded and possibly null terminated.
- * Returns TRUE if successful. - DISABLED (no caller ever checked) */
-/* FIXME: we leave field untouched if value doesn't fit. */
-/* This is not good - what will happen at untar time?? */
-static void putOctal(char *cp, int len, long long value)
+ * Stores low-order bits only if whole value does not fit.
+ * Returns FALSE if that happens. */
+static int putOctal(char *cp, int len, off_t value)
{
- int tempLength;
- /* long long for the sake of storing lengths of 4Gb+ files */
- /* (we are bust anyway after 64Gb: it doesn't fit into the field) */
- char tempBuffer[sizeof(long long)*3+1];
+ char tempBuffer[sizeof(off_t)*3+1];
char *tempString = tempBuffer;
+ int width;
- /* Create a string of the specified length with
- * leading zeroes and the octal number, and a trailing null. */
- tempLength = sprintf(tempBuffer, "%0*llo", len - 1, value);
+ width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
+ tempString += (width - len);
- /* If the string is too large, suppress leading 0's. */
- /* If that is not enough, drop trailing null. */
- tempLength -= len; /* easier to do checks */
- while (tempLength >= 0) {
- if (tempString[0] != '0') {
- if (!tempLength) {
- /* 1234 barely fits in 4 chars (w/o EOL '\0') */
- break;
- }
- /* 12345 doesn't fit into 4 chars */
- return /*FALSE*/;
- }
- tempLength--; /* still have leading '0', */
- tempString++; /* can afford to drop it but retain EOL '\0' */
- }
+ /* If string has leading zeroes, we can drop one */
+ /* and field will have trailing '\0' */
+ /* (increases chances of compat with other tars) */
+ if (tempString[0] == '0')
+ tempString++;
- /* Copy the string to the field. */
+ /* Copy the string to the field */
memcpy(cp, tempString, len);
- /*return TRUE;*/
+
+ /* If after shift we have zero - value did not overflow, */
+ /* return 1 (TRUE) then */
+ return (value >> (len*3)) == 0;
}
/* Write out a tar header for the specified file/directory/whatever */
@@ -203,12 +192,13 @@
safe_strncpy(header.name, header_name, sizeof(header.name));
+#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
/* POSIX says to mask mode with 07777. */
- putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 07777);
- putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
- putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
+ PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
+ PUT_OCTAL(header.uid, statbuf->st_uid);
+ PUT_OCTAL(header.gid, statbuf->st_gid);
memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
- putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
+ PUT_OCTAL(header.mtime, statbuf->st_mtime);
strcpy(header.magic, "ustar ");
/* Enter the user and group names */
@@ -240,25 +230,28 @@
strncat(header.name, "/", sizeof(header.name));
} else if (S_ISCHR(statbuf->st_mode)) {
header.typeflag = CHRTYPE;
- putOctal(header.devmajor, sizeof(header.devmajor),
- major(statbuf->st_rdev));
- putOctal(header.devminor, sizeof(header.devminor),
- minor(statbuf->st_rdev));
+ PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+ PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
} else if (S_ISBLK(statbuf->st_mode)) {
header.typeflag = BLKTYPE;
- putOctal(header.devmajor, sizeof(header.devmajor),
- major(statbuf->st_rdev));
- putOctal(header.devminor, sizeof(header.devminor),
- minor(statbuf->st_rdev));
+ PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+ PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
} else if (S_ISFIFO(statbuf->st_mode)) {
header.typeflag = FIFOTYPE;
} else if (S_ISREG(statbuf->st_mode)) {
header.typeflag = REGTYPE;
- putOctal(header.size, sizeof(header.size), statbuf->st_size);
+ if ((PUT_OCTAL(header.size, statbuf->st_size) == FALSE)
+ && sizeof(statbuf->st_size) > 4
+ ) {
+ bb_error_msg_and_die("cannot store file '%s' "
+ "of size %"OFF_FMT"d, aborting",
+ fileName, statbuf->st_size);
+ }
} else {
bb_error_msg("%s: unknown file type", fileName);
return FALSE;
}
+#undef PUT_OCTAL
/* Calculate and store the checksum (i.e., the sum of all of the bytes of
* the header). The checksum field must be filled with blanks for the