There are two cases where u32 variables n and err are being checked
for less than zero error values, the checks is always false because
the variables are not signed. Fix this by making the variables ints.
Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 345c0dbf3a ("ext4: protect journal inode's blocks using block_validity")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The buffer_head (frames[0].bh) and it's corresping page can be
potentially free'd once brelse() is done inside the for loop
but before the for loop exits in dx_release(). It can be free'd
in another context, when the page cache is flushed via
drop_caches_sysctl_handler(). This results into below data abort
when accessing info->indirect_levels in dx_release().
Unable to handle kernel paging request at virtual address ffffffc17ac3e01e
Call trace:
dx_release+0x70/0x90
ext4_htree_fill_tree+0x2d4/0x300
ext4_readdir+0x244/0x6f8
iterate_dir+0xbc/0x160
SyS_getdents64+0x94/0x174
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: stable@kernel.org
Unaligned AIO must be serialized because the zeroing of partial blocks
of unaligned AIO can result in data corruption in case it's overlapping
another in flight IO.
Currently we wait for all unwritten extents before we submit unaligned
AIO which protects data in case of unaligned AIO is following overlapping
IO. However if a unaligned AIO is followed by overlapping aligned AIO we
can still end up corrupting data.
To fix this, we must make sure that the unaligned AIO is the only IO in
flight by waiting for unwritten extents conversion not just before the
IO submission, but right after it as well.
This problem can be reproduced by xfstest generic/538
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
This commit zeroes out the unused memory region in the buffer_head
corresponding to the extent metablock after writing the extent header
and the corresponding extent node entries.
This is done to prevent random uninitialized data from getting into
the filesystem when the extent block is synced.
This fixes CVE-2019-11833.
Signed-off-by: Sriram Rajagopalan <sriramr@arista.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Instead of removing EXT4_MOUNT_JOURNAL_CHECKSUM from s_def_mount_opt as
I assume was intended, all other options were blown away leading to
_ext4_show_options() output being incorrect.
Fixes: 1e381f60da ("ext4: do not allow journal_opts for fs w/o journal")
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
This patch implements the actual support for case-insensitive file name
lookups in ext4, based on the feature bit and the encoding stored in the
superblock.
A filesystem that has the casefold feature set is able to configure
directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups
to succeed in that directory in a case-insensitive fashion, i.e: match
a directory entry even if the name used by userspace is not a byte per
byte match with the disk name, but is an equivalent case-insensitive
version of the Unicode string. This operation is called a
case-insensitive file name lookup.
The feature is configured as an inode attribute applied to directories
and inherited by its children. This attribute can only be enabled on
empty directories for filesystems that support the encoding feature,
thus preventing collision of file names that only differ by case.
* dcache handling:
For a +F directory, Ext4 only stores the first equivalent name dentry
used in the dcache. This is done to prevent unintentional duplication of
dentries in the dcache, while also allowing the VFS code to quickly find
the right entry in the cache despite which equivalent string was used in
a previous lookup, without having to resort to ->lookup().
d_hash() of casefolded directories is implemented as the hash of the
casefolded string, such that we always have a well-known bucket for all
the equivalencies of the same string. d_compare() uses the
utf8_strncasecmp() infrastructure, which handles the comparison of
equivalent, same case, names as well.
For now, negative lookups are not inserted in the dcache, since they
would need to be invalidated anyway, because we can't trust missing file
dentries. This is bad for performance but requires some leveraging of
the vfs layer to fix. We can live without that for now, and so does
everyone else.
* on-disk data:
Despite using a specific version of the name as the internal
representation within the dcache, the name stored and fetched from the
disk is a byte-per-byte match with what the user requested, making this
implementation 'name-preserving'. i.e. no actual information is lost
when writing to storage.
DX is supported by modifying the hashes used in +F directories to make
them case/encoding-aware. The new disk hashes are calculated as the
hash of the full casefolded string, instead of the string directly.
This allows us to efficiently search for file names in the htree without
requiring the user to provide an exact name.
* Dealing with invalid sequences:
By default, when a invalid UTF-8 sequence is identified, ext4 will treat
it as an opaque byte sequence, ignoring the encoding and reverting to
the old behavior for that unique file. This means that case-insensitive
file name lookup will not work only for that file. An optional bit can
be set in the superblock telling the filesystem code and userspace tools
to enforce the encoding. When that optional bit is set, any attempt to
create a file name using an invalid UTF-8 sequence will fail and return
an error to userspace.
* Normalization algorithm:
The UTF-8 algorithms used to compare strings in ext4 is implemented
lives in fs/unicode, and is based on a previous version developed by
SGI. It implements the Canonical decomposition (NFD) algorithm
described by the Unicode specification 12.1, or higher, combined with
the elimination of ignorable code points (NFDi) and full
case-folding (CF) as documented in fs/unicode/utf8_norm.c.
NFD seems to be the best normalization method for EXT4 because:
- It has a lower cost than NFC/NFKC (which requires
decomposing to NFD as an intermediary step)
- It doesn't eliminate important semantic meaning like
compatibility decompositions.
Although:
- This implementation is not completely linguistic accurate, because
different languages have conflicting rules, which would require the
specialization of the filesystem to a given locale, which brings all
sorts of problems for removable media and for users who use more than
one language.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Support for encoding is considered an incompatible feature, since it has
potential to create collisions of file names in existing filesystems.
If the feature flag is not enabled, the entire filesystem will operate
on opaque byte sequences, respecting the original behavior.
The s_encoding field stores a magic number indicating the encoding
format and version used globally by file and directory names in the
filesystem. The s_encoding_flags defines policies for using the charset
encoding, like how to handle invalid sequences. The magic number is
mapped to the exact charset table, but the mapping is specific to ext4.
Since we don't have any commitment to support old encodings, the only
encoding I am supporting right now is utf8-12.1.0.
The current implementation prevents the user from enabling encoding and
per-directory encryption on the same filesystem at the same time. The
incompatibility between these features lies in how we do efficient
directory searches when we cannot be sure the encryption of the user
provided fname will match the actual hash stored in the disk without
decrypting every directory entry, because of normalization cases. My
quickest solution is to simply block the concurrent use of these
features for now, and enable it later, once we have a better solution.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It is never possible, that number of block groups decreases,
since only online grow is supported.
But after a growing occured, we have to zero inode tables
for just created new block groups.
Fixes: 19c5246d25 ("ext4: add new online resize interface")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
When remounting with debug_want_extra_isize, we were not performing the
same checks that we do during a normal mount. That allowed us to set a
value for s_want_extra_isize that reached outside the s_inode_size.
Fixes: e2b911c535 ("ext4: clean up feature test macros with predicate functions")
Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Barret Rhoden <brho@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty.
However, the reference is dropped again if error occurs during
ext4_handle_dirty_metadata, which may result in use-after-free bugs.
Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Add the blocks which belong to the journal inode to block_validity's
system zone so attempts to deallocate or overwrite the journal due a
corrupted file system where the journal blocks are also claimed by
another inode.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
BUG_ON(1) leads to bogus warnings from clang when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set:
fs/ext4/inode.c:544:4: error: variable 'retval' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
BUG_ON(1);
^~~~~~~~~
include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/inode.c:591:6: note: uninitialized use occurs here
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
^~~~~~
fs/ext4/inode.c:544:4: note: remove the 'if' if its condition is always true
BUG_ON(1);
^
include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
^
fs/ext4/inode.c:502:12: note: initialize the variable 'retval' to silence this warning
Change it to BUG() so clang can see that this code path can never
continue.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
In ext4_mpage_readpages(), if the parameter pages is not NULL, another
parameter page is NULL. At the first time prefetchw(&page->flags)
works on NULL. From second time, prefetchw(&page->flags) always works on
the last consumed page. This might do little improvment for handling
current page. So prefetchw() should be called while the page pointer
has just been updated.
Signed-off-by: Liu Xiang <liu.xiang6@zte.com.cn>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The comment above NEXT_ORPHAN() was meant for ext4_encrypted_inode(),
which was moved by commit a7550b30ab ("ext4 crypto: migrate into vfs's
crypto engine") but the comment was accidentally left in place. Since
ext4_encrypted_inode() has now been removed, just remove the comment.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
The sanity check in mb_find_extent() only checked that returned extent
does not extend past blocksize * 8, however it should not extend past
EXT4_CLUSTERS_PER_GROUP(sb). This can happen when clusters_per_group <
blocksize * 8 and the tail of the bitmap is not properly filled by 1s
which happened e.g. when ancient kernels have grown the filesystem.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Pull ext4 fixes from Ted Ts'o:
"Miscellaneous ext4 bug fixes for 5.1"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: prohibit fstrim in norecovery mode
ext4: cleanup bh release code in ext4_ind_remove_space()
ext4: brelse all indirect buffer in ext4_ind_remove_space()
ext4: report real fs size after failed resize
ext4: add missing brelse() in add_new_gdb_meta_bg()
ext4: remove useless ext4_pin_inode()
ext4: avoid panic during forced reboot
ext4: fix data corruption caused by unaligned direct AIO
ext4: fix NULL pointer dereference while journal is aborted
The ext4 fstrim implementation uses the block bitmaps to find free space
that can be discarded. If we haven't replayed the journal, the bitmaps
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, we are releasing the indirect buffer where we are done with
it in ext4_ind_remove_space(), so we can see the brelse() and
BUFFER_TRACE() everywhere. It seems fragile and hard to read, and we
may probably forget to release the buffer some day. This patch cleans
up the code by putting of the code which releases the buffers to the
end of the function.
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
All indirect buffers get by ext4_find_shared() should be released no
mater the branch should be freed or not. But now, we forget to release
the lower depth indirect buffers when removing space from the same
higher depth indirect block. It will lead to buffer leak and futher
more, it may lead to quota information corruption when using old quota,
consider the following case.
- Create and mount an empty ext4 filesystem without extent and quota
features,
- quotacheck and enable the user & group quota,
- Create some files and write some data to them, and then punch hole
to some files of them, it may trigger the buffer leak problem
mentioned above.
- Disable quota and run quotacheck again, it will create two new
aquota files and write the checked quota information to them, which
probably may reuse the freed indirect block(the buffer and page
cache was not freed) as data block.
- Enable quota again, it will invoke
vfs_load_quota_inode()->invalidate_bdev() to try to clean unused
buffers and pagecache. Unfortunately, because of the buffer of quota
data block is still referenced, quota code cannot read the up to date
quota info from the device and lead to quota information corruption.
This problem can be reproduced by xfstests generic/231 on ext3 file
system or ext4 file system without extent and quota features.
This patch fix this problem by releasing the missing indirect buffers,
in ext4_ind_remove_space().
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Currently when the file system resize using ext4_resize_fs() fails it
will report into log that "resized filesystem to <requested block
count>". However this may not be true in the case of failure. Use the
current block count as returned by ext4_blocks_count() to report the
block count.
Additionally, report a warning that "error occurred during file system
resize"
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently in add_new_gdb_meta_bg() there is a missing brelse of gdb_bh
in case ext4_journal_get_write_access() fails.
Additionally kvfree() is missing in the same error path. Fix it by
moving the ext4_journal_get_write_access() before the ext4 sb update as
Ted suggested and release n_group_desc and gdb_bh in case it fails.
Fixes: 61a9c11e5e ("ext4: add missing brelse() add_new_gdb_meta_bg()'s error path")
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This function is never used from the beginning (and is commented out);
let's remove it.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Colin Ian King
Sahitya Tummala
Lukas Czerner
Sriram Rajagopalan
Theodore Ts'o
Debabrata Banerjee
Gabriel Krisman Bertazi
Kirill Tkhai
Khazhismel Kumykov
Barret Rhoden
Pan Bian
Arnd Bergmann
Liu Xiang
Eric Biggers
Jan Kara
Linus Torvalds
Darrick J. Wong
zhangyi (F)
Jason Yan