Add support for SEEK_DATA and SEEK_HOLE lseek() whence values.
These allow much faster searches for holes and data in sparse files, which
can significantly speed up file copying, e.g.
before (GNU coreutils, Debian 13):
cp --sparse=always big-file /
took real 11m58s, user 0m5.764s, sys 11m48s
after:
real 0.047s, user 0.000s, sys 0.027s
Where big-file has a 256 GB hole followed by 47 KB of data.
Link: https://lkml.kernel.org/r/20250923220652.568416-3-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Squashfs: performance improvement and a sanity check".
This patchset adds an additional sanity check when reading regular file
inodes, and adds support for SEEK_DATA/SEEK_HOLE lseek() whence values.
This patch (of 2):
Add an additional sanity check when reading regular file inodes.
A regular file if the file size is an exact multiple of the filesystem
block size cannot have a fragment. This is because by definition a
fragment block stores tailends which are not a whole block in size.
Link: https://lkml.kernel.org/r/20250923220652.568416-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20250923220652.568416-2-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug.
This is caused by open_by_handle_at() being called with a file handle
containing an invalid parent inode number. In particular the inode number
is that of a symbolic link, rather than a directory.
Squashfs_get_parent() gets called with that symbolic link inode, and
accesses the parent member field.
unsigned int parent_ino = squashfs_i(inode)->parent;
Because non-directory inodes in Squashfs do not have a parent value, this
is uninitialised, and this causes an uninitialised value access.
The fix is to initialise parent with the invalid inode 0, which will cause
an EINVAL error to be returned.
Regular inodes used to share the parent field with the block_list_start
field. This is removed in this commit to enable the parent field to
contain the invalid inode number 0.
Link: https://lkml.kernel.org/r/20250918233308.293861-1-phillip@squashfs.org.uk
Fixes: 122601408d ("Squashfs: export operations")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+157bdef5cf596ad0da2c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68cc2431.050a0220.139b6.0001.GAE@google.com/
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The inode mode loaded from corrupted disk might by error contain the file
type bits. Since the file type bits are set by squashfs_read_inode()
using bitwise OR, the file type bits must not be set by
squashfs_new_inode() from squashfs_read_inode(); otherwise, an invalid
file type bits later confuses may_open().
Link: https://lkml.kernel.org/r/f63d8d11-2254-4fc3-9292-9a43a93b374e@I-love.SAKURA.ne.jp
Reported-by: syzbot <syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Syzkiller reports a "KMSAN: uninit-value in pick_link" bug.
This is caused by an uninitialised page, which is ultimately caused
by a corrupted symbolic link size read from disk.
The reason why the corrupted symlink size causes an uninitialised
page is due to the following sequence of events:
1. squashfs_read_inode() is called to read the symbolic
link from disk. This assigns the corrupted value
3875536935 to inode->i_size.
2. Later squashfs_symlink_read_folio() is called, which assigns
this corrupted value to the length variable, which being a
signed int, overflows producing a negative number.
3. The following loop that fills in the page contents checks that
the copied bytes is less than length, which being negative means
the loop is skipped, producing an uninitialised page.
This patch adds a sanity check which checks that the symbolic
link size is not larger than expected.
--
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Link: https://lore.kernel.org/r/20240811232821.13903-1-phillip@squashfs.org.uk
Reported-by: Lizhi Xu <lizhi.xu@windriver.com>
Reported-by: syzbot+24ac24ff58dc5b0d26b9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000a90e8c061e86a76b@google.com/
V2: fix spelling mistake.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Syskiller has produced an out of bounds access in fill_meta_index().
That out of bounds access is ultimately caused because the inode
has an inode number with the invalid value of zero, which was not checked.
The reason this causes the out of bounds access is due to following
sequence of events:
1. Fill_meta_index() is called to allocate (via empty_meta_index())
and fill a metadata index. It however suffers a data read error
and aborts, invalidating the newly returned empty metadata index.
It does this by setting the inode number of the index to zero,
which means unused (zero is not a valid inode number).
2. When fill_meta_index() is subsequently called again on another
read operation, locate_meta_index() returns the previous index
because it matches the inode number of 0. Because this index
has been returned it is expected to have been filled, and because
it hasn't been, an out of bounds access is performed.
This patch adds a sanity check which checks that the inode number
is not zero when the inode is created and returns -EINVAL if it is.
[phillip@squashfs.org.uk: whitespace fix]
Link: https://lkml.kernel.org/r/20240409204723.446925-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20240408220206.435788-1-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: "Ubisectech Sirius" <bugreport@ubisectech.com>
Closes: https://lore.kernel.org/lkml/87f5c007-b8a5-41ae-8b57-431e924c5915.bugreport@ubisectech.com/
Cc: Christian Brauner <brauner@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-73-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation 51 franklin street fifth
floor boston ma 02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 23 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.458548087@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These inode operations are no longer used; remove them.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
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>
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>
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>
Add new extended inode types that store the xattr_id field.
Also add the necessary code changes to make xattrs visibile.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Move zlib buffer init/destroy code into separate wrapper file. Also
make zlib z_stream field a void * removing the need to include zlib.h
for most files.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Phillip Lougher