| Age | Commit message (Collapse) | Author |
|---|
|
btrfs_find_orphan_roots has this weird thing where it looks up the root
in cache to see if it is there before just reading the root. But the
read it uses just reads the root, it doesn't do any of the init work, we
do that by hand here. But this is unnecessary, all we really want is to
see if the root still exists and add it to the dead roots list to be
cleaned up, otherwise we delete the orphan item.
Fix this by just using btrfs_get_fs_root directly with check_ref set to
false so we get the orphan root items. Then we just handle in cache and
out of cache roots the same, add them to the dead roots list and carry
on.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We have a helper for reading fs roots that just reads the fs root off
the disk and then sets REF_COWS and init's the inheritable flags. Move
this into btrfs_init_fs_root so we can later get rid of this helper and
consolidate all of the fs root reading into one helper.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There's no reason to not init the root at alloc time, and with later
patches it actually causes problems if we error out mounting the fs
before the tree_root is init'ed because we expect it to have a valid ref
count. Fix this by pushing __setup_root into btrfs_alloc_root.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Now that we have a safe way to update the isize, remove all of this code
as it's no longer needed.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Now that we have a safe way to update the i_size, replace all uses of
btrfs_ordered_update_i_size with btrfs_inode_safe_disk_i_size_write.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We want to use this everywhere we modify the file extent items
permanently. These include:
1) Inserting new file extents for writes and prealloc extents.
2) Truncating inode items.
3) btrfs_cont_expand().
4) Insert inline extents.
5) Insert new extents from log replay.
6) Insert a new extent for clone, as it could be past i_size.
7) Hole punching
For hole punching in particular it might seem it's not necessary because
anybody extending would use btrfs_cont_expand, however there is a corner
that still can give us trouble. Start with an empty file and
fallocate KEEP_SIZE 1M-2M
We now have a 0 length file, and a hole file extent from 0-1M, and a
prealloc extent from 1M-2M. Now
punch 1M-1.5M
Because this is past i_size we have
[HOLE EXTENT][ NOTHING ][PREALLOC]
[0 1M][1M 1.5M][1.5M 2M]
with an i_size of 0. Now if we pwrite 0-1.5M we'll increas our i_size
to 1.5M, but our disk_i_size is still 0 until the ordered extent
completes.
However if we now immediately truncate 2M on the file we'll just call
btrfs_cont_expand(inode, 1.5M, 2M), since our old i_size is 1.5M. If we
commit the transaction here and crash we'll expose the gap.
To fix this we need to clear the file extent mapping for the range that
we punched but didn't insert a corresponding file extent for. This will
mean the truncate will only get an disk_i_size set to 1M if we crash
before the finish ordered io happens.
I've written an xfstest to reproduce the problem and validate this fix.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
In order to keep track of where we have file extents on disk, and thus
where it is safe to adjust the i_size to, we need to have a tree in
place to keep track of the contiguous areas we have file extents for.
Add helpers to use this tree, as it's not required for NO_HOLES file
systems. We will use this by setting DIRTY for areas we know we have
file extent item's set, and clearing it when we remove file extent items
for truncation.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We were using btrfs_i_size_write(), which unconditionally jacks up
inode->disk_i_size. However since clone can operate on ranges we could
have pending ordered extents for a range prior to the start of our clone
operation and thus increase disk_i_size too far and have a hole with no
file extent.
Fix this by using the btrfs_ordered_update_i_size helper which will do
the right thing in the face of pending ordered extents outside of our
clone range.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Btrfsctl was removed in 2012, now the function btrfs_control_ioctl()
is only used for devices ioctls. So update the comment.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Su Yue <Damenly_Su@gmx.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Relocation is one of the most complex part of btrfs, while it's also the
foundation stone for online resizing, profile converting.
For such a complex facility, we should at least have some introduction
to it.
This patch will add an basic introduction at pretty a high level,
explaining:
- What relocation does
- How relocation is done
Only mentioning how data reloc tree and reloc tree are involved in the
operation.
No details like the backref cache, or the data reloc tree contents.
- Which function to refer.
More detailed comments will be added for reloc tree creation, data reloc
tree creation and backref cache.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Each new element added to the mod seq list is always appended to the list,
and each one gets a sequence number coming from a counter which gets
incremented everytime a new element is added to the list (or a new node
is added to the tree mod log rbtree). Therefore the element with the
lowest sequence number is always the first element in the list.
So just remove the list iteration at btrfs_put_tree_mod_seq() that
computes the minimum sequence number in the list and replace it with
a check for the first element's sequence number.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The overview of btrfs dev-replace. It mentions some corner cases caused
by the write duplication and scrub based data copy.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ adjust wording ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Two fixes.
The first is a regression: when dropping some incompat bits the
conditions were reversed. The other is a fix for rename whiteout
potentially leaving stack memory linked to a list"
* tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix removal of raid[56|1c34} incompat flags after removing block group
btrfs: fix log context list corruption after rename whiteout error
|
|
Merge misc fixes from Andrew Morton:
"10 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
x86/mm: split vmalloc_sync_all()
mm, slub: prevent kmalloc_node crashes and memory leaks
mm/mmu_notifier: silence PROVE_RCU_LIST warnings
epoll: fix possible lost wakeup on epoll_ctl() path
mm: do not allow MADV_PAGEOUT for CoW pages
mm, memcg: throttle allocators based on ancestral memory.high
mm, memcg: fix corruption on 64-bit divisor in memory.high throttling
page-flags: fix a crash at SetPageError(THP_SWAP)
mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case
memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event
|
|
This fixes possible lost wakeup introduced by commit a218cc491420.
Originally modifications to ep->wq were serialized by ep->wq.lock, but
in commit a218cc491420 ("epoll: use rwlock in order to reduce
ep_poll_callback() contention") a new rw lock was introduced in order to
relax fd event path, i.e. callers of ep_poll_callback() function.
After the change ep_modify and ep_insert (both are called on epoll_ctl()
path) were switched to ep->lock, but ep_poll (epoll_wait) was using
ep->wq.lock on wqueue list modification.
The bug doesn't lead to any wqueue list corruptions, because wake up
path and list modifications were serialized by ep->wq.lock internally,
but actual waitqueue_active() check prior wake_up() call can be
reordered with modifications of ep ready list, thus wake up can be lost.
And yes, can be healed by explicit smp_mb():
list_add_tail(&epi->rdlink, &ep->rdllist);
smp_mb();
if (waitqueue_active(&ep->wq))
wake_up(&ep->wp);
But let's make it simple, thus current patch replaces ep->wq.lock with
the ep->lock for wqueue modifications, thus wake up path always observes
activeness of the wqueue correcty.
Fixes: a218cc491420 ("epoll: use rwlock in order to reduce ep_poll_callback() contention")
Reported-by: Max Neunhoeffer <max@arangodb.com>
Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Max Neunhoeffer <max@arangodb.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Christopher Kohlhoff <chris.kohlhoff@clearpool.io>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jes Sorensen <jes.sorensen@gmail.com>
Cc: <stable@vger.kernel.org> [5.1+]
Link: http://lkml.kernel.org/r/20200214170211.561524-1-rpenyaev@suse.de
References: https://bugzilla.kernel.org/show_bug.cgi?id=205933
Bisected-by: Max Neunhoeffer <max@arangodb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull io_uring fixes from Jens Axboe:
"Two different fixes in here:
- Fix for a potential NULL pointer deref for links with async or
drain marked (Pavel)
- Fix for not properly checking RLIMIT_NOFILE for async punted
operations.
This affects openat/openat2, which were added this cycle, and
accept4. I did a full audit of other cases where we might check
current->signal->rlim[] and found only RLIMIT_FSIZE for buffered
writes and fallocate. That one is fixed and queued for 5.7 and
marked stable"
* tag 'io_uring-5.6-20200320' of git://git.kernel.dk/linux-block:
io_uring: make sure accept honor rlimit nofile
io_uring: make sure openat/openat2 honor rlimit nofile
io_uring: NULL-deref for IOSQE_{ASYNC,DRAIN}
|
|
We are incorrectly dropping the raid56 and raid1c34 incompat flags when
there are still raid56 and raid1c34 block groups, not when we do not any
of those anymore. The logic just got unintentionally broken after adding
the support for the raid1c34 modes.
Fix this by clear the flags only if we do not have block groups with the
respective profiles.
Fixes: 9c907446dce3 ("btrfs: drop incompat bit for raid1c34 after last block group is gone")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Just like commit 4022e7af86be, this fixes the fact that
IORING_OP_ACCEPT ends up using get_unused_fd_flags(), which checks
current->signal->rlim[] for limits.
Add an extra argument to __sys_accept4_file() that allows us to pass
in the proper nofile limit, and grab it at request prep time.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Dmitry reports that a test case shows that io_uring isn't honoring a
modified rlimit nofile setting. get_unused_fd_flags() checks the task
signal->rlimi[] for the limits. As this isn't easily inheritable,
provide a __get_unused_fd_flags() that takes the value instead. Then we
can grab it when the request is prepared (from the original task), and
pass that in when we do the async part part of the open.
Reported-by: Dmitry Kadashev <dkadashev@gmail.com>
Tested-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Pull cifs fixes from Steve French:
"Three small smb3 fixes, two for stable"
* tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: fiemap: do not return EINVAL if get nothing
CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first
cifs: potential unintitliazed error code in cifs_getattr()
|
|
There is measurable performance impact in some synthetic tests due to
commit 6d390e4b5d48 (locks: fix a potential use-after-free problem when
wakeup a waiter). Fix the race condition instead by clearing the
fl_blocker pointer after the wake_up, using explicit acquire/release
semantics.
This does mean that we can no longer use the clearing of fl_blocker as
the wait condition, so switch the waiters over to checking whether the
fl_blocked_member list_head is empty.
Reviewed-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Fixes: 6d390e4b5d48 (locks: fix a potential use-after-free problem when wakeup a waiter)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
If we call fiemap on a truncated file with none blocks allocated,
it makes sense we get nothing from this call. No output means
no blocks have been counted, but the call succeeded. It's a valid
response.
Simple example reproducer:
xfs_io -f 'truncate 2M' -c 'fiemap -v' /cifssch/testfile
xfs_io: ioctl(FS_IOC_FIEMAP) ["/cifssch/testfile"]: Invalid argument
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
|
|
smb2_query_dir_first
The num_remote_opens counter keeps track of the number of open files which must be
maintained by the server at any point. This is a per-tree-connect counter, and the value
of this counter gets displayed in the /proc/fs/cifs/Stats output as a following...
Open files: 0 total (local), 1 open on server
^^^^^^^^^^^^^^^^
As a thumb-rule, we want to increment this counter for each open/create that we
successfully execute on the server. Similarly, we should decrement the counter when
we successfully execute a close.
In this case, an increment was being missed in case of smb2_query_dir_first,
in case of successful open. As a result, we would underflow the counter and we
could even see the counter go to negative after sufficient smb2_query_dir_first calls.
I tested the stats counter for a bunch of filesystem operations with the fix.
And it looks like the counter looks correct to me.
I also check if we missed the increments and decrements elsewhere. It does not
seem so. Few other cases where an open is done and we don't increment the counter are
the compound calls where the corresponding close is also sent in the request.
Signed-off-by: Shyam Prasad N <nspmangalore@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
|
|
Smatch complains that "rc" could be uninitialized.
fs/cifs/inode.c:2206 cifs_getattr() error: uninitialized symbol 'rc'.
Changing it to "return 0;" improves readability as well.
Fixes: cc1baf98c8f6 ("cifs: do not ignore the SYNC flags in getattr")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fix from Thomas Gleixner:
"Fix for yet another subtle futex issue.
The futex code used ihold() to prevent inodes from vanishing, but
ihold() does not guarantee inode persistence. Replace the inode
pointer with a per boot, machine wide, unique inode identifier.
The second commit fixes the breakage of the hash mechanism which
causes a 100% performance regression"
* tag 'locking-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Unbreak futex hashing
futex: Fix inode life-time issue
|
|
Processing links, io_submit_sqe() prepares requests, drops sqes, and
passes them with sqe=NULL to io_queue_sqe(). There IOSQE_DRAIN and/or
IOSQE_ASYNC requests will go through the same prep, which doesn't expect
sqe=NULL and fail with NULL pointer deference.
Always do full prepare including io_alloc_async_ctx() for linked
requests, and then it can skip the second preparation.
Cc: stable@vger.kernel.org # 5.5
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Pull NFS client bugfixes from Anna Schumaker:
"These are mostly fscontext fixes, but there is also one that fixes
collisions seen in fscache:
- Ensure the fs_context has the correct fs_type when mounting and
submounting
- Fix leaking of ctx->nfs_server.hostname
- Add minor version to fscache key to prevent collisions"
* tag 'nfs-for-5.6-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
nfs: add minor version to nfs_server_key for fscache
NFS: Fix leak of ctx->nfs_server.hostname
NFS: Don't hard-code the fs_type when submounting
NFS: Ensure the fs_context has the correct fs_type before mounting
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse fix from Miklos Szeredi:
"Fix an Oops introduced in v5.4"
* tag 'fuse-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: fix stack use after return
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi:
"Fix three bugs introduced in this cycle"
* tag 'ovl-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: fix lockdep warning for async write
ovl: fix some xino configurations
ovl: fix lock in ovl_llseek()
|
|
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
we can end up returning from btrfs_rename() with the log context object
still in the root's log context list - this happens if 'sync_log' was
set to true before we called btrfs_whiteout_for_rename() and it is
dangerous because we end up with a corrupt linked list (root->log_ctxs)
as the log context object was allocated on the stack.
After btrfs_rename() returns, any task that is running btrfs_sync_log()
concurrently can end up crashing because that linked list is traversed by
btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list
corruption after rename exchange operation") fixed.
Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Pull io_uring fix from Jens Axboe:
"Just a single fix here, improving the RCU callback ordering from last
week. After a bit more perusing by Paul, he poked a hole in the
original"
* tag 'io_uring-5.6-2020-03-13' of git://git.kernel.dk/linux-block:
io_uring: ensure RCU callback ordering with rcu_barrier()
|
|
afs_put_addrlist() casts kfree() to rcu_callback_t. Apart from being wrong
in theory, this might also blow up when people start enforcing function
types via compiler instrumentation, and it means the rcu_head has to be
first in struct afs_addr_list.
Use kfree_rcu() instead, it's simpler and more correct.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Lockdep reports "WARNING: lock held when returning to user space!" due to
async write holding freeze lock over the write. Apparently aio.c already
deals with this by lying to lockdep about the state of the lock.
Do the same here. No need to check for S_IFREG() here since these file ops
are regular-only.
Reported-by: syzbot+9331a354f4f624a52a55@syzkaller.appspotmail.com
Fixes: 2406a307ac7d ("ovl: implement async IO routines")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
|
|
Fix up two bugs in the coversion to xino_mode:
1. xino=off does not always end up in disabled mode
2. xino=auto on 32bit arch should end up in disabled mode
Take a proactive approach to disabling xino on 32bit kernel:
1. Disable XINO_AUTO config during build time
2. Disable xino with a warning on mount time
As a by product, xino=on on 32bit arch also ends up in disabled mode.
We never intended to enable xino on 32bit arch and this will make the
rest of the logic simpler.
Fixes: 0f831ec85eda ("ovl: simplify ovl_same_sb() helper")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
|
|
Pull vfs fixes from Al Viro:
"A couple of fixes for old crap in ->atomic_open() instances"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cifs_atomic_open(): fix double-put on late allocation failure
gfs2_atomic_open(): fix O_EXCL|O_CREAT handling on cold dcache
|
|
several iterations of ->atomic_open() calling conventions ago, we
used to need fput() if ->atomic_open() failed at some point after
successful finish_open(). Now (since 2016) it's not needed -
struct file carries enough state to make fput() work regardless
of the point in struct file lifecycle and discarding it on
failure exits in open() got unified. Unfortunately, I'd missed
the fact that we had an instance of ->atomic_open() (cifs one)
that used to need that fput(), as well as the stale comment in
finish_open() demanding such late failure handling. Trivially
fixed...
Fixes: fe9ec8291fca "do_last(): take fput() on error after opening to out:"
Cc: stable@kernel.org # v4.7+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
with the way fs/namei.c:do_last() had been done, ->atomic_open()
instances needed to recognize the case when existing file got
found with O_EXCL|O_CREAT, either by falling back to finish_no_open()
or failing themselves. gfs2 one didn't.
Fixes: 6d4ade986f9c (GFS2: Add atomic_open support)
Cc: stable@kernel.org # v3.11
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
ovl_inode_lock() is interruptible. When inode_lock() in ovl_llseek()
was replaced with ovl_inode_lock(), we did not add a check for error.
Fix this by making ovl_inode_lock() uninterruptible and change the
existing call sites to use an _interruptible variant.
Reported-by: syzbot+66a9752fa927f745385e@syzkaller.appspotmail.com
Fixes: b1f9d3858f72 ("ovl: use ovl_inode_lock in ovl_llseek()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
|
|
Pull fscrypt fix from Eric Biggers:
"Fix a bug where if userspace is writing to encrypted files while the
FS_IOC_REMOVE_ENCRYPTION_KEY ioctl (introduced in v5.4) is running,
dirty inodes could be evicted, causing writes could be lost or the
filesystem to hang due to a use-after-free. This was encountered
during real-world use, not just theoretical.
Tested with the existing fscrypt xfstests, and with a new xfstest I
wrote to reproduce this bug. This fix does expose an existing bug with
'-o lazytime' that Ted is working on fixing, but this fix is more
critical and needed anyway regardless of the lazytime fix"
* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
fscrypt: don't evict dirty inodes after removing key
|
|
After more careful studying, Paul informs me that we cannot rely on
ordering of RCU callbacks in the way that the the tagged commit did.
The current construct looks like this:
void C(struct rcu_head *rhp)
{
do_something(rhp);
call_rcu(&p->rh, B);
}
call_rcu(&p->rh, A);
call_rcu(&p->rh, C);
and we're relying on ordering between A and B, which isn't guaranteed.
Make this explicit instead, and have a work item issue the rcu_barrier()
to ensure that A has run before we manually execute B.
While thorough testing never showed this issue, it's dependent on the
per-cpu load in terms of RCU callbacks. The updated method simplifies
the code as well, and eliminates the need to maintain an rcu_head in
the fileset data.
Fixes: c1e2148f8ecb ("io_uring: free fixed_file_data after RCU grace period")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs fixes from Greg KH:
"Here are four small driver core / debugfs patches for 5.6-rc3:
- debugfs api cleanup now that all debugfs_create_regset32() callers
have been fixed up. This was waiting until after the -rc1 merge as
these fixes came in through different trees
- driver core sync state fixes based on reports of minor issues found
in the feature
All of these have been in linux-next with no reported issues"
* tag 'driver-core-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver core: Skip unnecessary work when device doesn't have sync_state()
driver core: Add dev_has_sync_state()
driver core: Call sync_state() even if supplier has no consumers
debugfs: remove return value of debugfs_create_regset32()
|
|
After FS_IOC_REMOVE_ENCRYPTION_KEY removes a key, it syncs the
filesystem and tries to get and put all inodes that were unlocked by the
key so that unused inodes get evicted via fscrypt_drop_inode().
Normally, the inodes are all clean due to the sync.
However, after the filesystem is sync'ed, userspace can modify and close
one of the files. (Userspace is *supposed* to close the files before
removing the key. But it doesn't always happen, and the kernel can't
assume it.) This causes the inode to be dirtied and have i_count == 0.
Then, fscrypt_drop_inode() failed to consider this case and indicated
that the inode can be dropped, causing the write to be lost.
On f2fs, other problems such as a filesystem freeze could occur due to
the inode being freed while still on f2fs's dirty inode list.
Fix this bug by making fscrypt_drop_inode() only drop clean inodes.
I've written an xfstest which detects this bug on ext4, f2fs, and ubifs.
Fixes: b1c0ec3599f4 ("fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl")
Cc: <stable@vger.kernel.org> # v5.4+
Link: https://lore.kernel.org/r/20200305084138.653498-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
|
|
Pull io_uring fixes from Jens Axboe:
"Here are a few io_uring fixes that should go into this release. This
contains:
- Removal of (now) unused io_wq_flush() and associated flag (Pavel)
- Fix cancelation lockup with linked timeouts (Pavel)
- Fix for potential use-after-free when freeing percpu ref for fixed
file sets
- io-wq cancelation fixups (Pavel)"
* tag 'io_uring-5.6-2020-03-07' of git://git.kernel.dk/linux-block:
io_uring: fix lockup with timeouts
io_uring: free fixed_file_data after RCU grace period
io-wq: remove io_wq_flush and IO_WQ_WORK_INTERNAL
io-wq: fix IO_WQ_WORK_NO_CANCEL cancellation
|
|
There is a recipe to deadlock the kernel: submit a timeout sqe with a
linked_timeout (e.g. test_single_link_timeout_ception() from liburing),
and SIGKILL the process.
Then, io_kill_timeouts() takes @ctx->completion_lock, but the timeout
isn't flagged with REQ_F_COMP_LOCKED, and will try to double grab it
during io_put_free() to cancel the linked timeout. Probably, the same
can happen with another io_kill_timeout() call site, that is
io_commit_cqring().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
"One fixup for DIO when in use with the new checksums, a missed case
where the checksum size was still assuming u32"
* tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix RAID direct I/O reads with alternate csums
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull file locking fixes from Jeff Layton:
"Just a couple of late-breaking patches for the file locking code. The
second patch (from yangerkun) fixes a rather nasty looking potential
use-after-free that should go to stable.
The other patch could technically wait for 5.7, but it's fairly
innocuous so I figured we might as well take it"
* tag 'filelock-v5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
locks: fix a potential use-after-free problem when wakeup a waiter
fcntl: Distribute switch variables for initialization
|
|
The percpu refcount protects this structure, and we can have an atomic
switch in progress when exiting. This makes it unsafe to just free the
struct normally, and can trigger the following KASAN warning:
BUG: KASAN: use-after-free in percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
Read of size 1 at addr ffff888181a19a30 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc4+ #5747
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
<IRQ>
dump_stack+0x76/0xa0
print_address_description.constprop.0+0x3b/0x60
? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
__kasan_report.cold+0x1a/0x3d
? percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
percpu_ref_switch_to_atomic_rcu+0xfa/0x1b0
rcu_core+0x370/0x830
? percpu_ref_exit+0x50/0x50
? rcu_note_context_switch+0x7b0/0x7b0
? run_rebalance_domains+0x11d/0x140
__do_softirq+0x10a/0x3e9
irq_exit+0xd5/0xe0
smp_apic_timer_interrupt+0x86/0x200
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:default_idle+0x26/0x1f0
Fix this by punting the final exit and free of the struct to RCU, then
we know that it's safe to do so. Jann suggested the approach of using a
double rcu callback to achieve this. It's important that we do a nested
call_rcu() callback, as otherwise the free could be ordered before the
atomic switch, even if the latter was already queued.
Reported-by: syzbot+e017e49c39ab484ac87a@syzkaller.appspotmail.com
Suggested-by: Jann Horn <jannh@google.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
'16306a61d3b7 ("fs/locks: always delete_block after waiting.")' add the
logic to check waiter->fl_blocker without blocked_lock_lock. And it will
trigger a UAF when we try to wakeup some waiter：
Thread 1 has create a write flock a on file, and now thread 2 try to
unlock and delete flock a, thread 3 try to add flock b on the same file.
Thread2 Thread3
flock syscall(create flock b)
...flock_lock_inode_wait
flock_lock_inode(will insert
our fl_blocked_member list
to flock a's fl_blocked_requests)
sleep
flock syscall(unlock)
...flock_lock_inode_wait
locks_delete_lock_ctx
...__locks_wake_up_blocks
__locks_delete_blocks(
b->fl_blocker = NULL)
...
break by a signal
locks_delete_block
b->fl_blocker == NULL &&
list_empty(&b->fl_blocked_requests)
success, return directly
locks_free_lock b
wake_up(&b->fl_waiter)
trigger UAF
Fix it by remove this logic, and this patch may also fix CVE-2019-19769.
Cc: stable@vger.kernel.org
Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
|
|
When get an error in the middle of reading an inode, some fields in the
inode might be still not initialized. And then the evict_inode path may
access those fields via iput().
To fix, this makes sure that inode fields are initialized.
Reported-by: syzbot+9d82b8de2992579da5d0@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/871rqnreqx.fsf@mail.parknet.co.jp
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.
This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
