found by Coverity. However, upon closer inspection the implementation of
fsck_ffs's fsck_readdir() and dircheck() functions is both nearly impossible
to follow and fails to check / fix directories in several cases. So, this
revision is an entire rewrite of these two functions to clarify what they
are doing and also to get something that works properly.
Referred by: cem
Reviewed by: kib, David G Lawrence
MFC after: 3 days
CID 1401317: namlen may be used uninitialized
directory entries that is caused by uninitialized directory entry
padding written to the disk. It can be viewed by any user with read
access to that directory. Up to 3 bytes of kernel stack are disclosed
per file entry, depending on the the amount of padding the kernel
needs to pad out the entry to a 32 bit boundry. The offset in the
kernel stack that is disclosed is a function of the filename size.
Furthermore, if the user can create files in a directory, this 3
byte window can be expanded 3 bytes at a time to a 254 byte window
with 75% of the data in that window exposed. The additional exposure
is done by removing the entry, creating a new entry with a 4-byte
longer name, extracting 3 more bytes by reading the directory, and
repeating until a 252 byte name is created.
This exploit works in part because the area of the kernel stack
that is being disclosed is in an area that typically doesn't change
that often (perhaps a few times a second on a lightly loaded system),
and these file creates and unlinks themselves don't overwrite the
area of kernel stack being disclosed.
It appears that this bug originated with the creation of the Fast
File System in 4.1b-BSD (Circa 1982, more than 36 years ago!), and
is likely present in every Unix or Unix-like system that uses
UFS/FFS. Amazingly, nobody noticed until now.
This update also adds the -z flag to fsck_ffs to have it scrub
the leaked information in the name padding of existing directories.
It only needs to be run once on each UFS/FFS filesystem after a
patched kernel is installed and running.
Submitted by: David G. Lawrence <dg@dglawrence.com>
Reviewed by: kib
MFC after: 1 week
document the libufs interface for fetching and storing inodes.
The undocumented getino / putino interface has been replaced
with a new getinode / putinode interface.
Convert the utilities that had been using the undocumented
interface to use the new documented interface.
No functional change (as for now the libufs library does not
do inode check-hashes).
Reviewed by: kib
Tested by: Peter Holm
Sponsored by: Netflix
Followup to r313780. Also prefix ext2's and nandfs's versions with
EXT2_ and NANDFS_.
Reported by: kib
Reviewed by: kib, mckusick
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D9623
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
errors have been detected in a particular run.
Clean up the global state variables so that a restart can happen correctly.
Separate the global variables in fsck_ffs and fsdb to their own file. This
fixes header sharing with fscd.
Correctly initialize, static-ize, and remove global variables as needed in
dir.c. This fixes a problem with lost+found directories that was causing
a segfault.
Correctly initialize, static-ize, and remove global variables as needed in
suj.c.
Initialize the suj globals before allocating the disk object, not after.
Also ensure that 'preen' mode doesn't conflict with 'restart' mode
Submitted by: scottl, max
Reviewed by: max, mckusick (earlier version)
Obtained from: Netflix
MFC after: 3 days
The value of namlen is copied from on-disk d_namlen, which is a 8-bit
unsigned integer which can never exceed MAXNAMLEN (255) so the test is
always true. Moreover, UFS does not allow d_namelen being zero.
Change namlen from u_int to u_int8_t, and replace the unneeded test
with a useful test.
PR: bin/160339
Submitted by: Eugene Grosbein <eugen grosbein.pp.ru>
MFC after: 2 weeks
Approved by: re (kib)
count of zero and instead encode this information in the inode state.
Pass 4 performed a linear search of this list for each inode in
the file system, which performs poorly if the list is long.
Reviewed by: sam & keramida (an earlier version of the patch), mckusick
MFC after: 1 month
original intention of the less restrictive permissions was to allow
users to move or delete recovered files that they own. However, it
is better to not create world-writable directories by default; the
administrator can always pre-create lost+found if different permissions
are desired.
Reviewed by: mckusick
filesystem expands the inode to 256 bytes to make space for 64-bit
block pointers. It also adds a file-creation time field, an ability
to use jumbo blocks per inode to allow extent like pointer density,
and space for extended attributes (up to twice the filesystem block
size worth of attributes, e.g., on a 16K filesystem, there is space
for 32K of attributes). UFS2 fully supports and runs existing UFS1
filesystems. New filesystems built using newfs can be built in either
UFS1 or UFS2 format using the -O option. In this commit UFS1 is
the default format, so if you want to build UFS2 format filesystems,
you must specify -O 2. This default will be changed to UFS2 when
UFS2 proves itself to be stable. In this commit the boot code for
reading UFS2 filesystems is not compiled (see /sys/boot/common/ufsread.c)
as there is insufficient space in the boot block. Once the size of the
boot block is increased, this code can be defined.
Things to note: the definition of SBSIZE has changed to SBLOCKSIZE.
The header file <ufs/ufs/dinode.h> must be included before
<ufs/ffs/fs.h> so as to get the definitions of ufs2_daddr_t and
ufs_lbn_t.
Still TODO:
Verify that the first level bootstraps work for all the architectures.
Convert the utility ffsinfo to understand UFS2 and test growfs.
Add support for the extended attribute storage. Update soft updates
to ensure integrity of extended attribute storage. Switch the
current extended attribute interfaces to use the extended attribute
storage. Add the extent like functionality (framework is there,
but is currently never used).
Sponsored by: DARPA & NAI Labs.
Reviewed by: Poul-Henning Kamp <phk@freebsd.org>
It does not help modern compilers, and some may take some hit from it.
(I also found several functions that listed *every* of its 10 local vars with
"register" -- just how many free registers do people think machines have?)
These were mainly missing casts or wrong format strings in printf
statements, but there were also missing includes, unused variables,
functions and arguments.
The choice of `long' vs `int' still seems almost random in a lot
of places though.
affect current systems until fsck is modified to use these new
facilities. To try out this change, set the fsck passno to zero
in /etc/fstab to cause the filesystem to be mounted without running
fsck, then run `fsck_ffs -p -B <filesystem>' after the system has
been brought up multiuser to run a background cleanup on <filesystem>.
Note that the <filesystem> in question must have soft updates enabled.
which sets the inoinfo's i_parent and i_dotdot to 0, but they never get
set to ROOTINO. This means that propagate will never find lost+found and
its descendents, subdirectories will remain DSTATE (instead of DFOUND)
even though they *are* correctly linked in, and pass4.c will try to
clear them unsuccessfully, thinking that there is no link count from the
DSTATE directory's parent. The result is that you need to run fsck twice
and get link count increasing errors (which are unexpected and fatal
when running in preen mode). The fix is to set i_parent and i_dotdot to
"parent" after the second cacheino() call in dir.c:allocdir().
Obtained from: "Ethan Solomita" <ethan@geocast.com> (of the NetBSD Project)
effect on operation of fsck on filesystems without snapshots.
If you get compilation errors, be sure that you have copies of
/usr/include/sys/mount.h (1.94), /usr/include/sys/stat.h (1.21),
and /usr/include/ufs/ffs/fs.h (1.16) as of July 4, 2000 or later.
Submitted by: Kirk McKusick <mckusick@McKusick.COM>
Obtained from: Mckusick, BSDI and a host of others
This exactly matches Kirks sources imported under the
Tag MCKUSICK2. These are as supplied by kirk with one small
change needed to compile under freeBSD.
Some FreeBSD patches will be added back, though many have been
added to Kirk's sources already.
which caused the reference count of a directory to get doubly
decremented.
PR: bin/8030
Reviewed by: nate
Submitted by: Don Lewis <Don.Lewis@tsc.tdk.com>
Subject: Fix for annoying fsck bug
Date: Wed, 24 Jan 1996 13:33:29 -0700 (MST)
The following small diff fixes the annoying fsck bug that causes it to
need to be run twice to end up with correct reference counts for inodes
for directories that had subdirectories relocated into the lost+found
directory.
I found the need to rerun *extremely* annoying. This fix causes the
count to be correctly adjusted later in pass 4 by correctly stating
the parent reference count.
Note that the parent reference count is incremented when the directory
entry is made (for ".."), but is not really there in the case of a
directory that does not make an entry in its parent dir.
This can be tested by waiting for the inode sync after cd'ing from a
shell into a test fs. Then you "mkdir xxx yyy zzz", wait a second,
and hit the machine reset button.
Reviewed by: nate (Tested lots of crashes :)
Submitted by: Terry Lambert <terry@lambert.org>
1) dir.c: get byte order right in mkentry()
2) pass1.c: When doing -c2 conversion, do secsize reads for a symlink -
not doing so was causing the conversion to fail because the device
driver can't deal with short reads.
