341 lines
12 KiB
Diff
341 lines
12 KiB
Diff
From 5abe86f88de3c61e369483a55afe771cce646135 Mon Sep 17 00:00:00 2001
|
||
From: Pavel Raiskup <praiskup@redhat.com>
|
||
Date: Tue, 26 Jan 2016 23:17:54 +0100
|
||
Subject: [PATCH 3/4] CVE-2016-2037 - 1 byte out-of-bounds write
|
||
|
||
Ensure that cpio_safer_name_suffix always works with dynamically
|
||
allocated buffer, and that it has size of at least 32 bytes.
|
||
Then, any call to cpio_safer_name_suffix is safe (it requires at
|
||
least 2 bytes in the buffer).
|
||
|
||
Also ensure that c_namesize is always correctly initialized (by
|
||
cpio_set_c_name) to avoid undefined behavior when reading
|
||
file_hdr.c_namesize (previously happened for tar archives).
|
||
|
||
References:
|
||
http://www.mail-archive.com/bug-cpio@gnu.org/msg00545.html
|
||
|
||
* src/copyin.c (query_rename): Drop the hack, as we now work with
|
||
dynamically allocated buffer. Use cpio_set_c_name.
|
||
(create_defered_links_to_skipped): Use cpio_set_c_name rather than
|
||
manual assignment.
|
||
(read_name_from_file): New function to avoid C&P.
|
||
(read_in_old_ascii, read_in_new_ascii, read_in_binary): Use
|
||
read_name_from_file.
|
||
(process_copy_in): Initialize file_hdr.c_namesize.
|
||
* src/copyout.c (process_copy_out): Use cpio_set_c_name.
|
||
* src/cpiohdr.h (cpio_set_c_name): New prototype.
|
||
* src/tar.c (read_in_tar_header): Use cpio_set_c_name.
|
||
* src/util.c (cpio_set_c_name): New function to set
|
||
file_hdr->c_name and c_namesize from arbitrary string.
|
||
(cpio_safer_name_suffix): Some docs fixes.
|
||
* tests/inout.at: Also test copy-in, and try various formats.
|
||
---
|
||
src/copyin.c | 68 ++++++++++++++++----------------------------------
|
||
src/copyout.c | 13 ++++------
|
||
src/cpiohdr.h | 1 +
|
||
src/tar.c | 10 +++++---
|
||
src/util.c | 32 +++++++++++++++++++++++-
|
||
tests/inout.at | 19 ++++++++++++--
|
||
6 files changed, 82 insertions(+), 61 deletions(-)
|
||
|
||
diff --git src/copyin.c src/copyin.c
|
||
index 05279d2..06ee1c3 100644
|
||
--- src/copyin.c
|
||
+++ src/copyin.c
|
||
@@ -76,28 +76,7 @@ query_rename(struct cpio_file_stat* file_hdr, FILE *tty_in, FILE *tty_out,
|
||
return -1;
|
||
}
|
||
else
|
||
- /* Debian hack: file_hrd.c_name is sometimes set to
|
||
- point to static memory by code in tar.c. This
|
||
- causes a segfault. This has been fixed and an
|
||
- additional check to ensure that the file name
|
||
- is not too long has been added. (Reported by
|
||
- Horst Knobloch.) This bug has been reported to
|
||
- "bug-gnu-utils@prep.ai.mit.edu". (99/1/6) -BEM */
|
||
- {
|
||
- if (archive_format != arf_tar && archive_format != arf_ustar)
|
||
- {
|
||
- free (file_hdr->c_name);
|
||
- file_hdr->c_name = xstrdup (new_name.ds_string);
|
||
- }
|
||
- else
|
||
- {
|
||
- if (is_tar_filename_too_long (new_name.ds_string))
|
||
- error (0, 0, _("%s: file name too long"),
|
||
- new_name.ds_string);
|
||
- else
|
||
- strcpy (file_hdr->c_name, new_name.ds_string);
|
||
- }
|
||
- }
|
||
+ cpio_set_c_name (file_hdr, new_name.ds_string);
|
||
return 0;
|
||
}
|
||
|
||
@@ -344,8 +323,7 @@ create_defered_links_to_skipped (struct cpio_file_stat *file_hdr,
|
||
d_prev->next = d->next;
|
||
else
|
||
deferments = d->next;
|
||
- free (file_hdr->c_name);
|
||
- file_hdr->c_name = xstrdup(d->header.c_name);
|
||
+ cpio_set_c_name (file_hdr, d->header.c_name);
|
||
free_deferment (d);
|
||
copyin_regular_file(file_hdr, in_file_des);
|
||
return 0;
|
||
@@ -1064,6 +1042,22 @@ read_in_header (struct cpio_file_stat *file_hdr, int in_des)
|
||
}
|
||
}
|
||
|
||
+static void
|
||
+read_name_from_file (struct cpio_file_stat *file_hdr, int fd, uintmax_t len)
|
||
+{
|
||
+ static char *tmp_filename;
|
||
+ static size_t buflen;
|
||
+
|
||
+ if (buflen < len)
|
||
+ {
|
||
+ buflen = len;
|
||
+ tmp_filename = xrealloc (tmp_filename, buflen);
|
||
+ }
|
||
+
|
||
+ tape_buffered_read (tmp_filename, fd, len);
|
||
+ cpio_set_c_name (file_hdr, tmp_filename);
|
||
+}
|
||
+
|
||
/* Fill in FILE_HDR by reading an old-format ASCII format cpio header from
|
||
file descriptor IN_DES, except for the magic number, which is
|
||
already filled in. */
|
||
@@ -1090,14 +1084,8 @@ read_in_old_ascii (struct cpio_file_stat *file_hdr, int in_des)
|
||
file_hdr->c_rdev_min = minor (dev);
|
||
|
||
file_hdr->c_mtime = FROM_OCTAL (ascii_header.c_mtime);
|
||
- file_hdr->c_namesize = FROM_OCTAL (ascii_header.c_namesize);
|
||
file_hdr->c_filesize = FROM_OCTAL (ascii_header.c_filesize);
|
||
-
|
||
- /* Read file name from input. */
|
||
- if (file_hdr->c_name != NULL)
|
||
- free (file_hdr->c_name);
|
||
- file_hdr->c_name = (char *) xmalloc (file_hdr->c_namesize + 1);
|
||
- tape_buffered_read (file_hdr->c_name, in_des, (long) file_hdr->c_namesize);
|
||
+ read_name_from_file (file_hdr, in_des, FROM_OCTAL (ascii_header.c_namesize));
|
||
|
||
/* HP/UX cpio creates archives that look just like ordinary archives,
|
||
but for devices it sets major = 0, minor = 1, and puts the
|
||
@@ -1152,14 +1140,8 @@ read_in_new_ascii (struct cpio_file_stat *file_hdr, int in_des)
|
||
file_hdr->c_dev_min = FROM_HEX (ascii_header.c_dev_min);
|
||
file_hdr->c_rdev_maj = FROM_HEX (ascii_header.c_rdev_maj);
|
||
file_hdr->c_rdev_min = FROM_HEX (ascii_header.c_rdev_min);
|
||
- file_hdr->c_namesize = FROM_HEX (ascii_header.c_namesize);
|
||
file_hdr->c_chksum = FROM_HEX (ascii_header.c_chksum);
|
||
-
|
||
- /* Read file name from input. */
|
||
- if (file_hdr->c_name != NULL)
|
||
- free (file_hdr->c_name);
|
||
- file_hdr->c_name = (char *) xmalloc (file_hdr->c_namesize);
|
||
- tape_buffered_read (file_hdr->c_name, in_des, (long) file_hdr->c_namesize);
|
||
+ read_name_from_file (file_hdr, in_des, FROM_HEX (ascii_header.c_namesize));
|
||
|
||
/* In SVR4 ASCII format, the amount of space allocated for the header
|
||
is rounded up to the next long-word, so we might need to drop
|
||
@@ -1207,16 +1189,9 @@ read_in_binary (struct cpio_file_stat *file_hdr,
|
||
file_hdr->c_rdev_min = minor (short_hdr->c_rdev);
|
||
file_hdr->c_mtime = (unsigned long) short_hdr->c_mtimes[0] << 16
|
||
| short_hdr->c_mtimes[1];
|
||
-
|
||
- file_hdr->c_namesize = short_hdr->c_namesize;
|
||
file_hdr->c_filesize = (unsigned long) short_hdr->c_filesizes[0] << 16
|
||
| short_hdr->c_filesizes[1];
|
||
-
|
||
- /* Read file name from input. */
|
||
- if (file_hdr->c_name != NULL)
|
||
- free (file_hdr->c_name);
|
||
- file_hdr->c_name = (char *) xmalloc (file_hdr->c_namesize);
|
||
- tape_buffered_read (file_hdr->c_name, in_des, (long) file_hdr->c_namesize);
|
||
+ read_name_from_file (file_hdr, in_des, short_hdr->c_namesize);
|
||
|
||
/* In binary mode, the amount of space allocated in the header for
|
||
the filename is `c_namesize' rounded up to the next short-word,
|
||
@@ -1297,6 +1272,7 @@ process_copy_in ()
|
||
read_pattern_file ();
|
||
}
|
||
file_hdr.c_name = NULL;
|
||
+ file_hdr.c_namesize = 0;
|
||
|
||
if (rename_batch_file)
|
||
{
|
||
diff --git src/copyout.c src/copyout.c
|
||
index 1f0987a..bb39559 100644
|
||
--- src/copyout.c
|
||
+++ src/copyout.c
|
||
@@ -660,8 +660,7 @@ process_copy_out ()
|
||
cpio_safer_name_suffix (input_name.ds_string, false,
|
||
!no_abs_paths_flag, true);
|
||
#ifndef HPUX_CDF
|
||
- file_hdr.c_name = input_name.ds_string;
|
||
- file_hdr.c_namesize = strlen (input_name.ds_string) + 1;
|
||
+ cpio_set_c_name (&file_hdr, input_name.ds_string);
|
||
#else
|
||
if ( (archive_format != arf_tar) && (archive_format != arf_ustar) )
|
||
{
|
||
@@ -670,16 +669,15 @@ process_copy_out ()
|
||
properly recreate the directory as hidden (in case the
|
||
files of a directory go into the archive before the
|
||
directory itself (e.g from "find ... -depth ... | cpio")). */
|
||
- file_hdr.c_name = add_cdf_double_slashes (input_name.ds_string);
|
||
- file_hdr.c_namesize = strlen (file_hdr.c_name) + 1;
|
||
+ cpio_set_c_name (&file_hdr,
|
||
+ add_cdf_double_slashes (input_name.ds_string));
|
||
}
|
||
else
|
||
{
|
||
/* We don't mark CDF's in tar files. We assume the "hidden"
|
||
directory will always go into the archive before any of
|
||
its files. */
|
||
- file_hdr.c_name = input_name.ds_string;
|
||
- file_hdr.c_namesize = strlen (input_name.ds_string) + 1;
|
||
+ cpio_set_c_name (&file_hdr, input_name.ds_string);
|
||
}
|
||
#endif
|
||
|
||
@@ -866,8 +864,7 @@ process_copy_out ()
|
||
file_hdr.c_chksum = 0;
|
||
|
||
file_hdr.c_filesize = 0;
|
||
- file_hdr.c_namesize = 11;
|
||
- file_hdr.c_name = CPIO_TRAILER_NAME;
|
||
+ cpio_set_c_name (&file_hdr, CPIO_TRAILER_NAME);
|
||
if (archive_format != arf_tar && archive_format != arf_ustar)
|
||
write_out_header (&file_hdr, out_file_des);
|
||
else
|
||
diff --git src/cpiohdr.h src/cpiohdr.h
|
||
index b29e6fb..f4c63be 100644
|
||
--- src/cpiohdr.h
|
||
+++ src/cpiohdr.h
|
||
@@ -129,5 +129,6 @@ struct cpio_file_stat /* Internal representation of a CPIO header */
|
||
char *c_tar_linkname;
|
||
};
|
||
|
||
+void cpio_set_c_name(struct cpio_file_stat *file_hdr, char *name);
|
||
|
||
#endif /* cpiohdr.h */
|
||
diff --git src/tar.c src/tar.c
|
||
index a2ce171..e41f89d 100644
|
||
--- src/tar.c
|
||
+++ src/tar.c
|
||
@@ -282,7 +282,7 @@ read_in_tar_header (struct cpio_file_stat *file_hdr, int in_des)
|
||
if (null_block ((long *) &tar_rec, TARRECORDSIZE))
|
||
#endif
|
||
{
|
||
- file_hdr->c_name = CPIO_TRAILER_NAME;
|
||
+ cpio_set_c_name (file_hdr, CPIO_TRAILER_NAME);
|
||
return;
|
||
}
|
||
#if 0
|
||
@@ -316,9 +316,11 @@ read_in_tar_header (struct cpio_file_stat *file_hdr, int in_des)
|
||
}
|
||
|
||
if (archive_format != arf_ustar)
|
||
- file_hdr->c_name = stash_tar_filename (NULL, tar_hdr->name);
|
||
+ cpio_set_c_name (file_hdr, stash_tar_filename (NULL, tar_hdr->name));
|
||
else
|
||
- file_hdr->c_name = stash_tar_filename (tar_hdr->prefix, tar_hdr->name);
|
||
+ cpio_set_c_name (file_hdr, stash_tar_filename (tar_hdr->prefix,
|
||
+ tar_hdr->name));
|
||
+
|
||
file_hdr->c_nlink = 1;
|
||
file_hdr->c_mode = FROM_OCTAL (tar_hdr->mode);
|
||
file_hdr->c_mode = file_hdr->c_mode & 07777;
|
||
@@ -398,7 +400,7 @@ read_in_tar_header (struct cpio_file_stat *file_hdr, int in_des)
|
||
case AREGTYPE:
|
||
/* Old tar format; if the last char in filename is '/' then it is
|
||
a directory, otherwise it's a regular file. */
|
||
- if (file_hdr->c_name[strlen (file_hdr->c_name) - 1] == '/')
|
||
+ if (file_hdr->c_name[file_hdr->c_namesize - 1] == '/')
|
||
file_hdr->c_mode |= CP_IFDIR;
|
||
else
|
||
file_hdr->c_mode |= CP_IFREG;
|
||
diff --git src/util.c src/util.c
|
||
index 6ff6032..4f3c073 100644
|
||
--- src/util.c
|
||
+++ src/util.c
|
||
@@ -1410,8 +1410,34 @@ set_file_times (int fd,
|
||
utime_error (name);
|
||
}
|
||
|
||
+
|
||
+void
|
||
+cpio_set_c_name (struct cpio_file_stat *file_hdr, char *name)
|
||
+{
|
||
+ static size_t buflen = 0;
|
||
+ size_t len = strlen (name) + 1;
|
||
+
|
||
+ if (buflen == 0)
|
||
+ {
|
||
+ buflen = len;
|
||
+ if (buflen < 32)
|
||
+ buflen = 32;
|
||
+ file_hdr->c_name = xmalloc (buflen);
|
||
+ }
|
||
+ else if (buflen < len)
|
||
+ {
|
||
+ buflen = len;
|
||
+ file_hdr->c_name = xrealloc (file_hdr->c_name, buflen);
|
||
+ }
|
||
+
|
||
+ file_hdr->c_namesize = len;
|
||
+ memmove (file_hdr->c_name, name, len);
|
||
+}
|
||
+
|
||
/* Do we have to ignore absolute paths, and if so, does the filename
|
||
- have an absolute path? */
|
||
+ have an absolute path? Before calling this function make sure that the
|
||
+ allocated NAME buffer has capacity at least 2 bytes. */
|
||
+
|
||
void
|
||
cpio_safer_name_suffix (char *name, bool link_target, bool absolute_names,
|
||
bool strip_leading_dots)
|
||
@@ -1426,6 +1452,10 @@ cpio_safer_name_suffix (char *name, bool link_target, bool absolute_names,
|
||
++p;
|
||
}
|
||
if (p != name)
|
||
+ /* The 'p' string is shortened version of 'name' with one exception; when
|
||
+ the 'name' points to an empty string (buffer where name[0] == '\0') the
|
||
+ 'p' then points to static string ".". So caller needs to ensure there
|
||
+ are at least two bytes available in 'name' buffer so memmove succeeds. */
|
||
memmove (name, p, (size_t)(strlen (p) + 1));
|
||
}
|
||
|
||
diff --git tests/inout.at tests/inout.at
|
||
index 60c3716..730cbd2 100644
|
||
--- tests/inout.at
|
||
+++ tests/inout.at
|
||
@@ -35,7 +35,22 @@ while read NAME LENGTH
|
||
do
|
||
genfile --length $LENGTH > $NAME
|
||
echo $NAME
|
||
-done < filelist |
|
||
- cpio --quiet -o > archive])
|
||
+done < filelist > filelist_raw
|
||
+
|
||
+for format in bin odc newc crc tar ustar hpbin hpodc
|
||
+do
|
||
+ cpio --format=$format --quiet -o < filelist_raw > archive.$format
|
||
+ rm -rf output
|
||
+ mkdir output && cd output
|
||
+ cpio -i --quiet < ../archive.$format
|
||
+
|
||
+ while read file
|
||
+ do
|
||
+ test -f $file || echo "$file not found"
|
||
+ done < ../filelist_raw
|
||
+
|
||
+ cd ..
|
||
+done
|
||
+])
|
||
|
||
AT_CLEANUP
|
||
--
|
||
2.20.1
|
||
|