commit 169b803397499be85bdd1e3d07d6f5e3d4bd669e upstream.
the victim might've been rmdir'ed just before the lock_rename();
unlike the normal callers, we do not look the source up after the
parents are locked - we know it beforehand and just recheck that it's
still the child of what used to be its parent. Unfortunately,
the check is too weak - we don't spot a dead directory since its
->d_parent is unchanged, dentry is positive, etc. So we sail all
the way to ->rename(), with hosting filesystems _not_ expecting
to be asked renaming an rmdir'ed subdirectory.
The fix is easy, fortunately - the lock on parent is sufficient for
making IS_DEADDIR() on child safe.
Cc: stable@vger.kernel.org
Fixes: 9ae326a690 (CacheFiles: A cache that backs onto a mounted filesystem)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ac081c3be3fae6d0cc3e1862507fca3862d30b67 ]
On non-preempt kernels this loop can take a long time (more than 50 ticks)
processing through entries.
Link: http://lkml.kernel.org/r/20181010172623.57033-1-khazhy@google.com
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 54a307ba8d3cd00a3902337ffaae28f436eeb1a4 upstream.
When event on child inodes are sent to the parent inode mark and
parent inode mark was not marked with FAN_EVENT_ON_CHILD, the event
will not be delivered to the listener process. However, if the same
process also has a mount mark, the event to the parent inode will be
delivered regadless of the mount mark mask.
This behavior is incorrect in the case where the mount mark mask does
not contain the specific event type. For example, the process adds
a mark on a directory with mask FAN_MODIFY (without FAN_EVENT_ON_CHILD)
and a mount mark with mask FAN_CLOSE_NOWRITE (without FAN_ONDIR).
A modify event on a file inside that directory (and inside that mount)
should not create a FAN_MODIFY event, because neither of the marks
requested to get that event on the file.
Fixes: 1968f5eed5 ("fanotify: use both marks when possible")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 16a34adb9392b2fe4195267475ab5b472e55292c upstream.
We want it only for the stuff created by SB_KERNMOUNT mounts, *not* for
their copies. As it is, creating a deep stack of bindings of /proc/*/ns/*
somewhere in a new namespace and exiting yields a stack overflow.
Reported-by: Alexander Aring <aring@mojatatu.com>
Bisected-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Tested-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Tested-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b8b784958eccbf8f51ebeee65282ca3fd59ea391 upstream.
Syzbot has reported that it can hit a NULL pointer dereference in
wb_workfn() due to wb->bdi->dev being NULL. This indicates that
wb_workfn() was called for an already unregistered bdi which should not
happen as wb_shutdown() called from bdi_unregister() should make sure
all pending writeback works are completed before bdi is unregistered.
Except that wb_workfn() itself can requeue the work with:
mod_delayed_work(bdi_wq, &wb->dwork, 0);
and if this happens while wb_shutdown() is waiting in:
flush_delayed_work(&wb->dwork);
the dwork can get executed after wb_shutdown() has finished and
bdi_unregister() has cleared wb->bdi->dev.
Make wb_workfn() use wakeup_wb() for requeueing the work which takes all
the necessary precautions against racing with bdi unregistration.
CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
CC: Tejun Heo <tj@kernel.org>
Fixes: 839a8e8660
Reported-by: syzbot <syzbot+9873874c735f2892e7e9@syzkaller.appspotmail.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Backported to 3.16:
- Use bdi_wakeup_thread() instead of wb_wakeup()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit e40ff213898502d299351cc2fe1e350cd186f0d3 upstream.
A malicious user could force the directory pointer to be in an invalid
spot by using seekdir(2). Use the mechanism we already have to notice
if the directory has changed since the last time we called
ext4_readdir() to force a revalidation of the pointer.
Reported-by: syzbot+1236ce66f79263e8a862@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: open-code inode_peek_iversion()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 54dd0e0a1b255f115f8647fc6fb93273251b01b9 upstream.
Add explicit checks in ext4_xattr_block_get() just in case the
e_value_offs and e_value_size fields in the the xattr block are
corrupted in memory after the buffer_verified bit is set on the xattr
block.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- Drop change to ext4_xattr_check_entries() which is only needed for the
xattr-in-inode case
- Adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d7614cc16146e3f0b4c33e71875c19607602aed5 upstream.
It was possible for an xattr value to have a very large size, which
would then pass validation on 32-bit architectures due to a pointer
wraparound. Fix this by validating the size in a way which avoids
pointer wraparound.
It was also possible that a value's size would fit in the available
space but its padded size would not. This would cause an out-of-bounds
memory write in ext4_xattr_set_entry when replacing the xattr value.
For example, if an xattr value of unpadded size 253 bytes went until the
very end of the inode or block, then using setxattr(2) to replace this
xattr's value with 256 bytes would cause a write to the 3 bytes past the
end of the inode or buffer, and the new xattr value would be incorrectly
truncated. Fix this by requiring that the padded size fit in the
available space rather than the unpadded size.
This patch shouldn't have any noticeable effect on
non-corrupted/non-malicious filesystems.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- s/EFSCORRUPTED/EIO/
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9496005d6ca4cf8f5ee8f828165a8956872dc59d upstream.
Add some paranoia checks to make sure we don't stray beyond the end of
the valid memory region containing ext4 xattr entries while we are
scanning for a match.
Also rename the function to xattr_find_entry() since it is static and
thus only used in fs/ext4/xattr.c
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- Keep passing an explicit size to xattr_find_entry()
- s/EFSCORRUPTED/EIO/]]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 73fdad00b208b139cf43f3163fbc0f67e4c6047c upstream.
i_disksize update should be protected by i_data_sem, by either taking
the lock explicitly or by using ext4_update_i_disksize() helper. But the
i_disksize updates in ext4_direct_IO_write() are not protected at all,
which may be racing with i_disksize updates in writeback path in
delalloc buffer write path.
This is found by code inspection, and I didn't hit any i_disksize
corruption due to this bug. Thanks to Jan Kara for catching this bug and
suggesting the fix!
Reported-by: Jan Kara <jack@suse.cz>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: The relevant code is in ext4_ind_direct_IO()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 044e6e3d74a3d7103a0c8a9305dfd94d64000660 upstream.
When reading the inode or block allocation bitmap, if the bitmap needs
to be initialized, do not update the checksum in the block group
descriptor. That's because we're not set up to journal those changes.
Instead, just set the verified bit on the bitmap block, so that it's
not necessary to validate the checksum.
When a block or inode allocation actually happens, at that point the
checksum will be calculated, and update of the bg descriptor block
will be properly journalled.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- Deleted code is slightly different
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 85e0c4e89c1b864e763c4e3bb15d0b6d501ad5d9 upstream.
This updates the jbd2 superblock unnecessarily, and on an abort we
shouldn't truncate the log.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5012284700775a4e6e3fbe7eac4c543c4874b559 upstream.
Commit 8844618d8aa7: "ext4: only look at the bg_flags field if it is
valid" will complain if block group zero does not have the
EXT4_BG_INODE_ZEROED flag set. Unfortunately, this is not correct,
since a freshly created file system has this flag cleared. It gets
almost immediately after the file system is mounted read-write --- but
the following somewhat unlikely sequence will end up triggering a
false positive report of a corrupted file system:
mkfs.ext4 /dev/vdc
mount -o ro /dev/vdc /vdc
mount -o remount,rw /dev/vdc
Instead, when initializing the inode table for block group zero, test
to make sure that itable_unused count is not too large, since that is
the case that will result in some or all of the reserved inodes
getting cleared.
This fixes the failures reported by Eric Whiteney when running
generic/230 and generic/231 in the the nojournal test case.
Fixes: 8844618d8aa7 ("ext4: only look at the bg_flags field if it is valid")
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8844618d8aa7a9973e7b527d038a2a589665002c upstream.
The bg_flags field in the block group descripts is only valid if the
uninit_bg or metadata_csum feature is enabled. We were not
consistently looking at this field; fix this.
Also block group #0 must never have uninitialized allocation bitmaps,
or need to be zeroed, since that's where the root inode, and other
special inodes are set up. Check for these conditions and mark the
file system as corrupted if they are detected.
This addresses CVE-2018-10876.
https://bugzilla.kernel.org/show_bug.cgi?id=199403
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- ext4_read_block_bitmap_nowait() and ext4_read_inode_bitmap() return
a pointer (NULL on error) instead of an error code
- Open-code sb_rdonly()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We should decrement free clusters counter when block bitmap is marked
as corrupt and free inodes counter when the allocation bitmap is
marked as corrupt to avoid misunderstanding due to incorrect available
size in statfs result. User can get immediately ENOSPC error from
write begin without reaching for the writepages.
Change-Id: I4074192c82fa1cc27e975d29b3717e9c8872d79e
Cc: Darrick J. Wong<darrick.wong@oracle.com>
Reported-by: Amit Sahrawat <amit.sahrawat83@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
If the group descriptor fails validation, mark the whole blockgroup
corrupt so that the inode/block allocators skip this group. The
previous approach takes the risk of writing to a damaged group
descriptor; hopefully it was never the case that the [ib]bitmap fields
pointed to another valid block and got dirtied, since the memset would
fill the page with 1s.
Change-Id: I6a79d8790c276bb4f17b4fa2ef7f827b4877e9ef
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If we detect either a discrepancy between the inode bitmap and the
inode counts or the inode bitmap fails to pass validation checks, mark
the block group corrupt and refuse to allocate or deallocate inodes
from the group.
Change-Id: Ie920071f5ed9bc3f1b841fa189307a111cf33821
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we notice a block-bitmap corruption (because of device failure or
something else), we should mark this group as corrupt and prevent
further block allocations/deallocations from it. Currently, we end up
generating one error message for every block in the bitmap. This
potentially could make the system unstable as noticed in some
bugs. With this patch, the error will be printed only the first time
and mark the entire block group as corrupted. This prevents future
access allocations/deallocations from it.
Also tested by corrupting the block
bitmap and forcefully introducing the mb_free_blocks error:
(1) create a largefile (2Gb)
$ dd if=/dev/zero of=largefile oflag=direct bs=10485760 count=200
(2) umount filesystem. use dumpe2fs to see which block-bitmaps
are in use by largefile and note their block numbers
(3) use dd to zero-out the used block bitmaps
$ dd if=/dev/zero of=/dev/hdc4 bs=4096 seek=14 count=8 oflag=direct
(4) mount the FS and delete the largefile.
(5) recreate the largefile. verify that the new largefile does not
get any blocks from the groups marked as bad.
Without the patch, we will see mb_free_blocks error for each bit in
each zero'ed out bitmap at (4). With the patch, we only see the error
once per blockgroup:
[ 309.706803] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 15: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.720824] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 14: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.732858] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.748321] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 13: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.760331] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.769695] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 12: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.781721] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.798166] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 11: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.810184] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.819532] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 10: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
Google-Bug-Id: 7258357
[darrick.wong@oracle.com]
Further modifications (by Darrick) to make more obvious that this corruption
bit applies to blocks only. Set the corruption flag if the block group bitmap
verification fails.
Original-author: Aditya Kali <adityakali@google.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The block_group parameter to ext4_validate_block_bitmap is both used
as a ext4_group_t inside the function and the same type is passed in
by all callers. We might as well use the typedef consistently instead
of open-coding the 'unsigned int'.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The block bitmap verification code assumes that calling ext4_error()
either panics the system or makes the fs readonly. However, this is
not always true: when 'errors=continue' is specified, an error is
printed but we don't return any indication of error to the caller,
which is (probably) the block allocator, which pretends that the crud
we read in off the disk is a usable bitmap. Yuck.
A block bitmap that fails the check should at least return no bitmap
to the caller. The block allocator should be told to go look in a
different group, but that's a separate issue.
The easiest way to reproduce this is to modify bg_block_bitmap (on a
^flex_bg fs) to point to a block outside the block group; or you can
create a metadata_csum filesystem and zero out the block bitmaps.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The group number passed to ext4_get_group_info() should be valid, but
let's add an assert to check this before we start creating a pointer
based on that group number and dereferencing it.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
commit 4d982e25d0bdc83d8c64e66fdeca0b89240b3b85 upstream.
A specially crafted file system can trick empty_inline_dir() into
reading past the last valid entry in a inline directory, and then run
into the end of xattr marker. This will trigger a divide by zero
fault. Fix this by using the size of the inline directory instead of
dir->i_size.
Also clean up error reporting in __ext4_check_dir_entry so that the
message is clearer and more understandable --- and avoids the division
by zero trap if the size passed in is zero. (I'm not sure why we
coded it that way in the first place; printing offset % size is
actually more confusing and less useful.)
https://bugzilla.kernel.org/show_bug.cgi?id=200933
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Wen Xu <wen.xu@gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Filesystem encryption ostensibly supported revoking a keyring key that
had been used to "unlock" encrypted files, causing those files to become
"locked" again. This was, however, buggy for several reasons, the most
severe of which was that when key revocation happened to be detected for
an inode, its fscrypt_info was immediately freed, even while other
threads could be using it for encryption or decryption concurrently.
This could be exploited to crash the kernel or worse.
This patch fixes the use-after-free by removing the code which detects
the keyring key having been revoked, invalidated, or expired. Instead,
an encrypted inode that is "unlocked" now simply remains unlocked until
it is evicted from memory. Note that this is no worse than the case for
block device-level encryption, e.g. dm-crypt, and it still remains
possible for a privileged user to evict unused pages, inodes, and
dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
simply unmounting the filesystem. In fact, one of those actions was
already needed anyway for key revocation to work even somewhat sanely.
This change is not expected to break any applications.
In the future I'd like to implement a real API for fscrypt key
revocation that interacts sanely with ongoing filesystem operations ---
waiting for existing operations to complete and blocking new operations,
and invalidating and sanitizing key material and plaintext from the VFS
caches. But this is a hard problem, and for now this bug must be fixed.
This bug affected almost all versions of ext4, f2fs, and ubifs
encryption, and it was potentially reachable in any kernel configured
with encryption support (CONFIG_EXT4_ENCRYPTION=y,
CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
shared fs/crypto/ code, but due to the potential security implications
of this bug, it may still be worthwhile to backport this fix to them.
Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
Change-Id: Ic805c3b7cd391aedef3495214057fc1ca64b9acf
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Michael Halcrow <mhalcrow@google.com>
The current mainline has copies propagated to *all* nodes, then
tears down the copies we made for nodes that do not contain
counterparts of the desired mountpoint. That sets the right
propagation graph for the copies (at teardown time we move
the slaves of removed node to a surviving peer or directly
to master), but we end up paying a fairly steep price in
useless allocations. It's fairly easy to create a situation
where N calls of mount(2) create exactly N bindings, with
O(N^2) vfsmounts allocated and freed in process.
Fortunately, it is possible to avoid those allocations/freeings.
The trick is to create copies in the right order and find which
one would've eventually become a master with the current algorithm.
It turns out to be possible in O(nodes getting propagation) time
and with no extra allocations at all.
One part is that we need to make sure that eventual master will be
created before its slaves, so we need to walk the propagation
tree in a different order - by peer groups. And iterate through
the peers before dealing with the next group.
Another thing is finding the (earlier) copy that will be a master
of one we are about to create; to do that we are (temporary) marking
the masters of mountpoints we are attaching the copies to.
Either we are in a peer of the last mountpoint we'd dealt with,
or we have the following situation: we are attaching to mountpoint M,
the last copy S_0 had been attached to M_0 and there are sequences
S_0...S_n, M_0...M_n such that S_{i+1} is a master of S_{i},
S_{i} mounted on M{i} and we need to create a slave of the first S_{k}
such that M is getting propagation from M_{k}. It means that the master
of M_{k} will be among the sequence of masters of M. On the
other hand, the nearest marked node in that sequence will either
be the master of M_{k} or the master of M_{k-1} (the latter -
in the case if M_{k-1} is a slave of something M gets propagation
from, but in a wrong peer group).
So we go through the sequence of masters of M until we find
a marked one (P). Let N be the one before it. Then we go through
the sequence of masters of S_0 until we find one (say, S) mounted
on a node D that has P as master and check if D is a peer of N.
If it is, S will be the master of new copy, if not - the master of S
will be.
That's it for the hard part; the rest is fairly simple. Iterator
is in next_group(), handling of one prospective mountpoint is
propagate_one().
It seems to survive all tests and gives a noticably better performance
than the current mainline for setups that are seriously using shared
subtrees.
Change-Id: I45648e8a405544f768c5956711bdbdf509e2705a
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If the dest_mnt is not shared, propagate_mnt() does nothing -
there's no mounts to propagate to and thus no copies to create.
Might as well don't bother calling it in that case.
Change-Id: Id94af8ad288bf9bfc6ffb5570562bbc2dc2e0d87
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The macro hides some control flow, making it easier
to run into bugs.
bug: 111642636
Change-Id: I37ec207c277d97c4e7f1e8381bc9ae743ad78435
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Rosenberg <drosen@google.com>
commit db86be3a12d0b6e5c5b51c2ab2a48f06329cb590 upstream.
We're freeing the list iterator so we should be using the _safe()
version of hlist_for_each_entry().
Fixes: 88b4a07e66 ("[PATCH] eCryptfs: Public key transport mechanism")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit f66665c09ab489a11ca490d6a82df57cfc1bea3e upstream.
In eCryptfs, we failed to verify that the authentication token keys are
not revoked before dereferencing their payloads, which is problematic
because the payload of a revoked key is NULL. request_key() *does* skip
revoked keys, but there is still a window where the key can be revoked
before we acquire the key semaphore.
Fix it by updating ecryptfs_get_key_payload_data() to return
-EKEYREVOKED if the key payload is NULL. For completeness we check this
for "encrypted" keys as well as "user" keys, although encrypted keys
cannot be revoked currently.
Alternatively we could use key_validate(), but since we'll also need to
fix ecryptfs_get_key_payload_data() to validate the payload length, it
seems appropriate to just check the payload pointer.
Fixes: 237fead619 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
[bwh: Backported to 3.16: user key payload is key->payload.data, not
key->payload.data[0]]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 69c433ed2ecd2d3264efd7afec4439524b319121 upstream.
Add a simple read-only counter to super_block that indicates how deep this
is in the stack of filesystems. Previously ecryptfs was the only stackable
filesystem and it explicitly disallowed multiple layers of itself.
Overlayfs, however, can be stacked recursively and also may be stacked
on top of ecryptfs or vice versa.
To limit the kernel stack usage we must limit the depth of the
filesystem stack. Initially the limit is set to 2.
Change-Id: I2659379e1ba70d1f41290d378b6a032b0b4cdd23
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
[bwh: Backported to 3.2:
- Drop changes to overlayfs
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Remove leftover files from checkout to LA.BR.1.3.6-04510-8976.0
fixes: "fs: ecryptfs: Checkout to LA.BR.1.3.6-04510-8976.0"
Change-Id: I855e2910666b6ead5566091e12a4c21c1dc66f14
next_descendent did not properly handle the case
where the initial mount had no slaves. In this case,
we would look for the next slave, but since don't
have a master, the check for wrapping around to the
start of the list will always fail. Instead, we check
for this case, and ensure that we end the iteration
when we come back to the root.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 62094374
Change-Id: I43dfcee041aa3730cb4b9a1161418974ef84812e
Git-commit: d2460846d407d7d670fa5efda87417f56d0c619b
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
commit da029c11e6b12f321f36dac8771e833b65cec962 upstream.
To avoid pathological stack usage or the need to special-case setuid
execs, just limit all arg stack usage to at most 75% of _STK_LIM (6MB).
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: replaced code is slightly different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8bc1379b82b8e809eef77a9fedbb75c6c297be19 upstream.
Use a separate journal transaction if it turns out that we need to
convert an inline file to use an data block. Otherwise we could end
up failing due to not having journal credits.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The function has a bit non-standard (for ext4) error recovery in that it
used a mix of 'out' labels and testing for 'handle' being NULL. There
isn't a good reason for that in the function so clean it up a bit.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Similarly as other ->write_begin functions in ext4, also
ext4_da_write_inline_data_begin() should retry allocation if the
conversion failed because of ENOSPC. This avoids returning ENOSPC
prematurely because of uncommitted block deletions.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
commit e09463f220ca9a1a1ecfda84fcda658f99a1f12a upstream.
Do not set the b_modified flag in block's journal head should not
until after we're sure that jbd2_journal_dirty_metadat() will not
abort with an error due to there not being enough space reserved in
the jbd2 handle.
Otherwise, future attempts to modify the buffer may lead a large
number of spurious errors and warnings.
This addresses CVE-2018-10883.
https://bugzilla.kernel.org/show_bug.cgi?id=200071
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: Drop the added logging statement, as it's on
a code path that doesn't exist here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c37e9e013469521d9adb932d17a1795c139b36db upstream.
If there is a directory entry pointing to a system inode (such as a
journal inode), complain and declare the file system to be corrupted.
Also, if the superblock's first inode number field is too small,
refuse to mount the file system.
This addresses CVE-2018-10882.
https://bugzilla.kernel.org/show_bug.cgi?id=200069
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6e8ab72a812396996035a37e5ca4b3b99b5d214b upstream.
When converting from an inode from storing the data in-line to a data
block, ext4_destroy_inline_data_nolock() was only clearing the on-disk
copy of the i_blocks[] array. It was not clearing copy of the
i_blocks[] in ext4_inode_info, in i_data[], which is the copy actually
used by ext4_map_blocks().
This didn't matter much if we are using extents, since the extents
header would be invalid and thus the extents could would re-initialize
the extents tree. But if we are using indirect blocks, the previous
contents of the i_blocks array will be treated as block numbers, with
potentially catastrophic results to the file system integrity and/or
user data.
This gets worse if the file system is using a 1k block size and
s_first_data is zero, but even without this, the file system can get
quite badly corrupted.
This addresses CVE-2018-10881.
https://bugzilla.kernel.org/show_bug.cgi?id=200015
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8cdb5240ec5928b20490a2bb34cb87e9a5f40226 upstream.
When expanding the extra isize space, we must never move the
system.data xattr out of the inode body. For performance reasons, it
doesn't make any sense, and the inline data implementation assumes
that system.data xattr is never in the external xattr block.
This addresses CVE-2018-10880
https://bugzilla.kernel.org/show_bug.cgi?id=200005
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 513f86d73855ce556ea9522b6bfd79f87356dc3a upstream.
If there an inode points to a block which is also some other type of
metadata block (such as a block allocation bitmap), the
buffer_verified flag can be set when it was validated as that other
metadata block type; however, it would make a really terrible external
attribute block. The reason why we use the verified flag is to avoid
constantly reverifying the block. However, it doesn't take much
overhead to make sure the magic number of the xattr block is correct,
and this will avoid potential crashes.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Change-Id: Id646f6a18051424549124eefba787608437a0da4
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5369a762c882c0b6e9599e4ebbb3a9ba9eee7e2d upstream.
In theory this should have been caught earlier when the xattr list was
verified, but in case it got missed, it's simple enough to add check
to make sure we don't overrun the xattr buffer.
This addresses CVE-2018-10879.
https://bugzilla.kernel.org/show_bug.cgi?id=200001
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
[bwh: Backported to 3.16:
- Add inode parameter to ext4_xattr_set_entry() and update callers
- Return -EIO instead of -EFSCORRUPTED on error
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 44de022c4382541cebdd6de4465d1f4f465ff1dd upstream.
Ext4_check_descriptors() was getting called before s_gdb_count was
initialized. So for file systems w/o the meta_bg feature, allocation
bitmaps could overlap the block group descriptors and ext4 wouldn't
notice.
For file systems with the meta_bg feature enabled, there was a
fencepost error which would cause the ext4_check_descriptors() to
incorrectly believe that the block allocation bitmap overlaps with the
block group descriptor blocks, and it would reject the mount.
Fix both of these problems.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 77260807d1170a8cf35dbb06e07461a655f67eee upstream.
It's really bad when the allocation bitmaps and the inode table
overlap with the block group descriptors, since it causes random
corruption of the bg descriptors. So we really want to head those off
at the pass.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: Open-code sb_rdonly()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 upstream.
If some metadata block, such as an allocation bitmap, overlaps the
superblock, it's very likely that if the file system is mounted
read/write, the results will not be pretty. So disallow r/w mounts
for file systems corrupted in this particular way.
Backport notes:
3.18.y is missing bc98a42c1f7d ("VFS: Convert sb->s_flags & MS_RDONLY
to sb_rdonly(sb)") and e462ec50cb5f ("VFS: Differentiate mount flags
(MS_*) from internal superblock flags") so we simply use the sb
MS_RDONLY check from pre bc98a42c1f7d in place of the sb_rdonly
function used in the upstream variant of the patch.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Harsh Shandilya <harsh@prjkt.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream.
Regardless of whether the flex_bg feature is set, we should always
check to make sure the bits we are setting in the block bitmap are
within the block group bounds.
https://bugzilla.kernel.org/show_bug.cgi?id=199865
Change-Id: Ib881b6930242229711188464685110e9528fc005
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
