We read the type field from disk. This value should be sanity
checked for correctness to avoid an out of bounds access when
reading the squashfs_filetype_table array.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
We read the size (of the name) field from disk. This value should
be sanity checked for correctness to avoid blindly reading
huge amounts of unnecessary data from disk on corruption.
Note, here we're not actually reading the name into a buffer, but
skipping it, and so corruption doesn't cause buffer overflow, merely
lots of unnecessary amounts of data to be read.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
The dir_count and size fields when read from disk are sanity
checked for correctness. However, the sanity checks only check the
values are not greater than expected. As dir_count and size were
incorrectly defined as signed ints, this can lead to corrupted values
appearing as negative which are not trapped.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
The dir_count and size fields when read from disk are sanity
checked for correctness. However, the sanity checks only check the
values are not greater than expected. As dir_count and size were
incorrectly defined as signed ints, this can lead to corrupted values
appearing as negative which are not trapped.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Patch "Squashfs: sanity check information from disk" from
Dan Carpenter adds a missing check for corruption in the
"size" field while reading the directory index from disk.
It, however, sets err to -EINVAL, this value is not used later, and
so setting it is completely redundant. So remove it.
Errors in reading the index are deliberately non-fatal. If we
get an error in reading the index we just return the part of the
index we have managed to read - the index isn't essential,
just quicker.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Merged the two for loops. We might get a little gain by overlapping
wait_on_bh and the memcpy operations.
Signed-off-by: Manish Sharma <manishrma@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
We read the size of the name from the disk, but a larger name than
expected would cause memory corruption.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Somehow I failed to add the MODULE_ALIAS_FS for cifs, hostfs, hpfs,
squashfs, and udf despite what I thought were my careful checks :(
Add them now.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull vfs update from Al Viro:
- big one - consolidation of descriptor-related logics; almost all of
that is moved to fs/file.c
(BTW, I'm seriously tempted to rename the result to fd.c. As it is,
we have a situation when file_table.c is about handling of struct
file and file.c is about handling of descriptor tables; the reasons
are historical - file_table.c used to be about a static array of
struct file we used to have way back).
A lot of stray ends got cleaned up and converted to saner primitives,
disgusting mess in android/binder.c is still disgusting, but at least
doesn't poke so much in descriptor table guts anymore. A bunch of
relatively minor races got fixed in process, plus an ext4 struct file
leak.
- related thing - fget_light() partially unuglified; see fdget() in
there (and yes, it generates the code as good as we used to have).
- also related - bits of Cyrill's procfs stuff that got entangled into
that work; _not_ all of it, just the initial move to fs/proc/fd.c and
switch of fdinfo to seq_file.
- Alex's fs/coredump.c spiltoff - the same story, had been easier to
take that commit than mess with conflicts. The rest is a separate
pile, this was just a mechanical code movement.
- a few misc patches all over the place. Not all for this cycle,
there'll be more (and quite a few currently sit in akpm's tree)."
Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
MAX_LFS_FILESIZE should be a loff_t
compat: fs: Generic compat_sys_sendfile implementation
fs: push rcu_barrier() from deactivate_locked_super() to filesystems
btrfs: reada_extent doesn't need kref for refcount
coredump: move core dump functionality into its own file
coredump: prevent double-free on an error path in core dumper
usb/gadget: fix misannotations
fcntl: fix misannotations
ceph: don't abuse d_delete() on failure exits
hypfs: ->d_parent is never NULL or negative
vfs: delete surplus inode NULL check
switch simple cases of fget_light to fdget
new helpers: fdget()/fdput()
switch o2hb_region_dev_write() to fget_light()
proc_map_files_readdir(): don't bother with grabbing files
make get_file() return its argument
vhost_set_vring(): turn pollstart/pollstop into bool
switch prctl_set_mm_exe_file() to fget_light()
switch xfs_find_handle() to fget_light()
switch xfs_swapext() to fget_light()
...
There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument. And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
Pull squashfs updates from Phillip Lougher:
"Add an extra mount time sanity check, plus some code cleanups and bug
fixes."
* tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
Squashfs: add mount time sanity check for block_size and block_log match
Squashfs: fix f_pos check in get_dir_index_using_offset
Squashfs: get rid of obsolete definitions in header file
Squashfs: remove redundant length initialisation in squashfs_lookup
Squashfs: remove redundant length initialisation in squashfs_readdir
Squashfs: update comment removing reference to zlib only
Squashfs: use define instead of constant
Pull vfs pile 1 from Al Viro:
"This is _not_ all; in particular, Miklos' and Jan's stuff is not there
yet."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
ext4: initialization of ext4_li_mtx needs to be done earlier
debugfs-related mode_t whack-a-mole
hfsplus: add an ioctl to bless files
hfsplus: change finder_info to u32
hfsplus: initialise userflags
qnx4: new helper - try_extent()
qnx4: get rid of qnx4_bread/qnx4_getblk
take removal of PF_FORKNOEXEC to flush_old_exec()
trim includes in inode.c
um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
um: embed ->stub_pages[] into mmu_context
gadgetfs: list_for_each_safe() misuse
ocfs2: fix leaks on failure exits in module_init
ecryptfs: make register_filesystem() the last potential failure exit
ntfs: forgets to unregister sysctls on register_filesystem() failure
logfs: missing cleanup on register_filesystem() failure
jfs: mising cleanup on register_filesystem() failure
make configfs_pin_fs() return root dentry on success
configfs: configfs_create_dir() has parent dentry in dentry->d_parent
configfs: sanitize configfs_create()
...
Squashfs currently has a sanity check for block_size less than or
equal to the maximum block_size (1 Mbyte). This catches some
superblock corruption, but obviously with a block_size maximum
of 1 Mbyte there's 7 correct values (4K, 8K, 16K, 32K, ... etc) and
a lot of incorrect values which are not caught by this check.
The Squashfs superblock, however, has both a block_size and
a block_log (2^block_log == block_size). Checking that the block_size
matches the block_log is a much more robust check. Corruption of the
superblock is unlikely to produce values which match, and it also
ensures the block_size is an exact power of two.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
One off error in the f_pos check. If f_pos is 3 or less don't
bother reading the index because we're at the start of the
directory, and we obviously already know where that is on disk.
This eliminates an unnecessary read.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Most of these were never used by the kernel code, but belong to
the time when the header file was used by both the kernel code
and the user space tools.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Comment was written when Squashfs only supported zlib compression.
This comment is now misleading given Squashfs supports other
compression algorithms.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Its better to use defined name instead of constant
Signed-off-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The le64_to_cpu() forces the calculation to be unsigned, with
the effect that it can underflow leading to an incorrect large
value.
This bug only triggers in rare(ish) circumstances, an empty file
encoded as an extended regular file or a completely sparse file.
Normally empty files are encoded as a regular file rather than as
an extended regular file (and the regular file i_blocks calculation
doesn't have this bug). To save space regular file inodes are
optimised to encode the most commonly occurring files. Less
common regular files are encoded using extended regular file inodes
which contain extra information.
Empty files with nlinks greater than 1, and or empty files
with extended attributes are encoded using extended regular file
inodes and they will hit this bug.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
A Squashfs filesystem containing nothing but an empty directory,
although unusual and ultimately pointless, is still valid.
The directory_table >= next_table sanity check rejects these
filesystems as invalid because the directory_table is empty and
equal to next_table.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
squashfs_cache_get() iterates over all entries to search for
block its looking for. Often get() / put() are called for
same block.
If we cache the current entry index, then we can optimise the
subsequent *_get() calls.
Signed-off-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
This commit adds an option to set the device block size used to 4K.
By default Squashfs sets the device block size (sb_min_blocksize) to 1K
or the smallest block size supported by the block device (if larger).
This, because blocks are packed together and unaligned in Squashfs,
should reduce latency.
This, however, gives poor performance on MTD NAND devices where
the optimal I/O size is 4K (even though the devices can support
smaller block sizes).
Using a 4K device block size may also improve overall I/O
performance for some file access patterns (e.g. sequential
accesses of files in filesystem order) on all media.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.
Fix these broken references, sometimes by dropping the irrelevant text
they were part of.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
Squashfs: Make ZLIB compression support optional
Squashfs: Update documentation for XZ and add squashfs-tools devel tree
Squashfs now supports XZ and LZO compression in addition to ZLIB.
As such it no longer makes sense to always include ZLIB support.
In particular embedded systems may only use LZO or XZ compression, and
the ability to exclude ZLIB support will reduce kernel size.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
d_splice_alias(NULL, dentry) is equivalent to d_add(dentry, NULL), NULL
so no need for that if (inode) ... in there (or ERR_PTR(0), for that
matter)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
Squashfs: update email address
Squashfs: add extra sanity checks at mount time
Squashfs: add sanity checks to fragment reading at mount time
Squashfs: add sanity checks to lookup table reading at mount time
Squashfs: add sanity checks to id reading at mount time
Squashfs: add sanity checks to xattr reading at mount time
Squashfs: reverse order of filesystem table reading
Squashfs: move table allocation into squashfs_read_table()
My existing email address may stop working in a month or two, so update
email to one that will continue working.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock fragments field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time fragment table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock inodes field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time lookup table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock no_ids field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time id table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reverse order of table reading from mostly first to last in placement
order, to last to first. This is to enable extra superblock sanity
checks to be added in later patches.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
