73184 Commits

Author SHA1 Message Date
Christian Brauner
47b5d0a753 fs/mount_setattr: always cleanup mount_kattr
commit 012e332286e2bb9f6ac77d195f17e74b2963d663 upstream.

Make sure that finish_mount_kattr() is called after mount_kattr was
succesfully built in both the success and failure case to prevent
leaking any references we took when we built it.  We returned early if
path lookup failed thereby risking to leak an additional reference we
took when building mount_kattr when an idmapped mount was requested.

Cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 9caccd41541a ("fs: introduce MOUNT_ATTR_IDMAP")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-05 12:42:39 +01:00
Jeffle Xu
35f9ff45ee netfs: fix parameter of cleanup()
commit 3cfef1b612e15a0c2f5b1c9d3f3f31ad72d56fcd upstream.

The order of these two parameters is just reversed. gcc didn't warn on
that, probably because 'void *' can be converted from or to other
pointer types without warning.

Cc: stable@vger.kernel.org
Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers")
Fixes: e1b1240c1ff5 ("netfs: Add write_begin helper")
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Link: https://lore.kernel.org/r/20211207031449.100510-1-jefflexu@linux.alibaba.com/ # v1
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:59 +01:00
Chao Yu
a8a9d753ed f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
commit 5598b24efaf4892741c798b425d543e4bed357a1 upstream.

As Wenqing Liu reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215235

- Overview
page fault in f2fs_setxattr() when mount and operate on corrupted image

- Reproduce
tested on kernel 5.16-rc3, 5.15.X under root

1. unzip tmp7.zip
2. ./single.sh f2fs 7

Sometimes need to run the script several times

- Kernel dump
loop0: detected capacity change from 0 to 131072
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Mounted with checkpoint version = 7548c2ee
BUG: unable to handle page fault for address: ffffe47bc7123f48
RIP: 0010:kfree+0x66/0x320
Call Trace:
 __f2fs_setxattr+0x2aa/0xc00 [f2fs]
 f2fs_setxattr+0xfa/0x480 [f2fs]
 __f2fs_set_acl+0x19b/0x330 [f2fs]
 __vfs_removexattr+0x52/0x70
 __vfs_removexattr_locked+0xb1/0x140
 vfs_removexattr+0x56/0x100
 removexattr+0x57/0x80
 path_removexattr+0xa3/0xc0
 __x64_sys_removexattr+0x17/0x20
 do_syscall_64+0x37/0xb0
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is in __f2fs_setxattr(), we missed to do sanity check on
last xattr entry, result in out-of-bound memory access during updating
inconsistent xattr data of target inode.

After the fix, it can detect such xattr inconsistency as below:

F2FS-fs (loop11): inode (7) has invalid last xattr entry, entry_size: 60676
F2FS-fs (loop11): inode (8) has corrupted xattr
F2FS-fs (loop11): inode (8) has corrupted xattr
F2FS-fs (loop11): inode (8) has invalid last xattr entry, entry_size: 47736

Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:59 +01:00
Marcos Del Sol Vives
a2c144d176 ksmbd: disable SMB2_GLOBAL_CAP_ENCRYPTION for SMB 3.1.1
commit 83912d6d55be10d65b5268d1871168b9ebe1ec4b upstream.

According to the official Microsoft MS-SMB2 document section 3.3.5.4, this
flag should be used only for 3.0 and 3.0.2 dialects. Setting it for 3.1.1
is a violation of the specification.

This causes my Windows 10 client to detect an anomaly in the negotiation,
and disable encryption entirely despite being explicitly enabled in ksmbd,
causing all data transfers to go in plain text.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org # v5.15
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:57 +01:00
Namjae Jeon
f43ba86a82 ksmbd: fix uninitialized symbol 'pntsd_size'
commit f2e78affc48dee29b989c1d9b0d89b503dcd1204 upstream.

No check for if "rc" is an error code for build_sec_desc().
This can cause problems with using uninitialized pntsd_size.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org # v5.15
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:57 +01:00
Dan Carpenter
89d0ffb4bb ksmbd: fix error code in ndr_read_int32()
commit ef399469d9ceb9f2171cdd79863f9434b9fa3edc upstream.

This is a failure path and it should return -EINVAL instead of success.
Otherwise it could result in the caller using uninitialized memory.

Fixes: 303fff2b8c77 ("ksmbd: add validation for ndr read/write functions")
Cc: stable@vger.kernel.org # v5.15
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:57 +01:00
Jens Axboe
20fb0dc35b io_uring: zero iocb->ki_pos for stream file types
[ Upstream commit 7b9762a5e8837b92a027d58d396a9d27f6440c36 ]

io_uring supports using offset == -1 for using the current file position,
and we read that in as part of read/write command setup. For the non-iter
read/write types we pass in NULL for the position pointer, but for the
iter types we should not be passing any anything but 0 for the position
for a stream.

Clear kiocb->ki_pos if the file is a stream, don't leave it as -1. If we
do, then the request will error with -ESPIPE.

Fixes: ba04291eb66e ("io_uring: allow use of offset == -1 to mean file position")
Link: https://github.com/axboe/liburing/discussions/501
Reported-by: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-29 12:28:45 +01:00
Chuck Lever
eabc0aab98 NFSD: Fix READDIR buffer overflow
commit 53b1119a6e5028b125f431a0116ba73510d82a72 upstream.

If a client sends a READDIR count argument that is too small (say,
zero), then the buffer size calculation in the new init_dirlist
helper functions results in an underflow, allowing the XDR stream
functions to write beyond the actual buffer.

This calculation has always been suspect. NFSD has never sanity-
checked the READDIR count argument, but the old entry encoders
managed the problem correctly.

With the commits below, entry encoding changed, exposing the
underflow to the pointer arithmetic in xdr_reserve_space().

Modern NFS clients attempt to retrieve as much data as possible
for each READDIR request. Also, we have no unit tests that
exercise the behavior of READDIR at the lower bound of @count
values. Thus this case was missed during testing.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: f5dcccd647da ("NFSD: Update the NFSv2 READDIR entry encoder to use struct xdr_stream")
Fixes: 7f87fc2d34d4 ("NFSD: Update NFSv3 READDIR entry encoders to use struct xdr_stream")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:38 +01:00
Zhang Yi
49c29e13fc ext4: check for inconsistent extents between index and leaf block
commit 9c6e071913792d80894cd0be98cc3c4b770e26d3 upstream.

Now that we can check out overlapping extents in leaf block and
out-of-order index extents in index block. But the .ee_block in the
first extent of one leaf block should equal to the .ei_block in it's
parent index extent entry. This patch add a check to verify such
inconsistent between the index and leaf block.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210908120850.4012324-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:37 +01:00
Zhang Yi
f71ab21b1a ext4: check for out-of-order index extents in ext4_valid_extent_entries()
commit 8dd27fecede55e8a4e67eef2878040ecad0f0d33 upstream.

After commit 5946d089379a ("ext4: check for overlapping extents in
ext4_valid_extent_entries()"), we can check out the overlapping extent
entry in leaf extent blocks. But the out-of-order extent entry in index
extent blocks could also trigger bad things if the filesystem is
inconsistent. So this patch add a check to figure out the out-of-order
index extents and return error.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20210908120850.4012324-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:37 +01:00
Zhang Yi
02f825cf02 ext4: prevent partial update of the extent blocks
commit 0f2f87d51aebcf71a709b52f661d681594c7dffa upstream.

In the most error path of current extents updating operations are not
roll back partial updates properly when some bad things happens(.e.g in
ext4_ext_insert_extent()). So we may get an inconsistent extents tree
if journal has been aborted due to IO error, which may probability lead
to BUGON later when we accessing these extent entries in errors=continue
mode. This patch drop extent buffer's verify flag before updatng the
contents in ext4_ext_get_access(), and reset it after updating in
__ext4_ext_dirty(). After this patch we could force to check the extent
buffer if extents tree updating was break off, make sure the extents are
consistent.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20210908120850.4012324-4-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:36 +01:00
Jens Axboe
11053a0219 io-wq: drop wqe lock before creating new worker
commit d800c65c2d4eccebb27ffb7808e842d5b533823c upstream.

We have two io-wq creation paths:

- On queue enqueue
- When a worker goes to sleep

The latter invokes worker creation with the wqe->lock held, but that can
run into problems if we end up exiting and need to cancel the queued work.
syzbot caught this:

============================================
WARNING: possible recursive locking detected
5.16.0-rc4-syzkaller #0 Not tainted
--------------------------------------------
iou-wrk-6468/6471 is trying to acquire lock:
ffff88801aa98018 (&wqe->lock){+.+.}-{2:2}, at: io_worker_cancel_cb+0xb7/0x210 fs/io-wq.c:187

but task is already holding lock:
ffff88801aa98018 (&wqe->lock){+.+.}-{2:2}, at: io_wq_worker_sleeping+0xb6/0x140 fs/io-wq.c:700

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&wqe->lock);
  lock(&wqe->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by iou-wrk-6468/6471:
 #0: ffff88801aa98018 (&wqe->lock){+.+.}-{2:2}, at: io_wq_worker_sleeping+0xb6/0x140 fs/io-wq.c:700

stack backtrace:
CPU: 1 PID: 6471 Comm: iou-wrk-6468 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
 check_deadlock kernel/locking/lockdep.c:2999 [inline]
 validate_chain+0x5984/0x8240 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5027
 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5637
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 io_worker_cancel_cb+0xb7/0x210 fs/io-wq.c:187
 io_wq_cancel_tw_create fs/io-wq.c:1220 [inline]
 io_queue_worker_create+0x3cf/0x4c0 fs/io-wq.c:372
 io_wq_worker_sleeping+0xbe/0x140 fs/io-wq.c:701
 sched_submit_work kernel/sched/core.c:6295 [inline]
 schedule+0x67/0x1f0 kernel/sched/core.c:6323
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1857
 wait_woken+0xca/0x1b0 kernel/sched/wait.c:460
 unix_msg_wait_data net/unix/unix_bpf.c:32 [inline]
 unix_bpf_recvmsg+0x7f9/0xe20 net/unix/unix_bpf.c:77
 unix_stream_recvmsg+0x214/0x2c0 net/unix/af_unix.c:2832
 sock_recvmsg_nosec net/socket.c:944 [inline]
 sock_recvmsg net/socket.c:962 [inline]
 sock_read_iter+0x3a7/0x4d0 net/socket.c:1035
 call_read_iter include/linux/fs.h:2156 [inline]
 io_iter_do_read fs/io_uring.c:3501 [inline]
 io_read fs/io_uring.c:3558 [inline]
 io_issue_sqe+0x144c/0x9590 fs/io_uring.c:6671
 io_wq_submit_work+0x2d8/0x790 fs/io_uring.c:6836
 io_worker_handle_work+0x808/0xdd0 fs/io-wq.c:574
 io_wqe_worker+0x395/0x870 fs/io-wq.c:630
 ret_from_fork+0x1f/0x30

We can safely drop the lock before doing work creation, making the two
contexts the same in that regard.

Reported-by: syzbot+b18b8be69df33a3918e9@syzkaller.appspotmail.com
Fixes: 71a85387546e ("io-wq: check for wq exit after adding new worker task_work")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:51 +01:00
Jens Axboe
4b4e5bbf93 io-wq: check for wq exit after adding new worker task_work
commit 71a85387546e50b1a37b0fa45dadcae3bfb35cf6 upstream.

We check IO_WQ_BIT_EXIT before attempting to create a new worker, and
wq exit cancels pending work if we have any. But it's possible to have
a race between the two, where creation checks exit finding it not set,
but we're in the process of exiting. The exit side will cancel pending
creation task_work, but there's a gap where we add task_work after we've
canceled existing creations at exit time.

Fix this by checking the EXIT bit post adding the creation task_work.
If it's set, run the same cancelation that exit does.

Reported-and-tested-by: syzbot+b60c982cb0efc5e05a47@syzkaller.appspotmail.com
Reviewed-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:51 +01:00
Jens Axboe
024f9c7cd3 io-wq: remove spurious bit clear on task_work addition
commit e47498afeca9a0c6d07eeeacc46d563555a3f677 upstream.

There's a small race here where the task_work could finish and drop
the worker itself, so that by the time that task_work_add() returns
with a successful addition we've already put the worker.

The worker callbacks clear this bit themselves, so we don't actually
need to manually clear it in the caller. Get rid of it.

Reported-by: syzbot+b60c982cb0efc5e05a47@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:51 +01:00
Miklos Szeredi
d2ccdd4e4e ovl: fix warning in ovl_create_real()
commit 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c upstream.

Syzbot triggered the following warning in ovl_workdir_create() ->
ovl_create_real():

	if (!err && WARN_ON(!newdentry->d_inode)) {

The reason is that the cgroup2 filesystem returns from mkdir without
instantiating the new dentry.

Weird filesystems such as this will be rejected by overlayfs at a later
stage during setup, but to prevent such a warning, call ovl_mkdir_real()
directly from ovl_workdir_create() and reject this case early.

Reported-and-tested-by: syzbot+75eab84fd0af9e8bf66b@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:50 +01:00
Miklos Szeredi
4658f2a9b3 fuse: annotate lock in fuse_reverse_inval_entry()
commit bda9a71980e083699a0360963c0135657b73f47a upstream.

Add missing inode lock annotatation; found by syzbot.

Reported-and-tested-by: syzbot+9f747458f5990eaa8d43@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:50 +01:00
Thiago Rafael Becker
c63433a09d cifs: sanitize multiple delimiters in prepath
commit a31080899d5fdafcccf7f39dd214a814a2c82626 upstream.

mount.cifs can pass a device with multiple delimiters in it. This will
cause rename(2) to fail with ENOENT.

V2:
  - Make sanitize_path more readable.
  - Fix multiple delimiters between UNC and prepath.
  - Avoid a memory leak if a bad user starts putting a lot of delimiters
    in the path on purpose.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2031200
Fixes: 24e0a1eff9e2 ("cifs: switch to new mount api")
Cc: stable@vger.kernel.org # 5.11+
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Thiago Rafael Becker <trbecker@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:48 +01:00
Naohiro Aota
d153ff65a9 zonefs: add MODULE_ALIAS_FS
commit 8ffea2599f63fdbee968b894eab78170abf3ec2c upstream.

Add MODULE_ALIAS_FS() to load the module automatically when you do "mount
-t zonefs".

Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: stable <stable@vger.kernel.org> # 5.6+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:48 +01:00
Shin'ichiro Kawasaki
210ab4e3c0 btrfs: fix missing blkdev_put() call in btrfs_scan_one_device()
commit 4989d4a0aed3fb30f5b48787a689d7090de6f86d upstream.

The function btrfs_scan_one_device() calls blkdev_get_by_path() and
blkdev_put() to get and release its target block device. However, when
btrfs_sb_log_location_bdev() fails, blkdev_put() is not called and the
block device is left without clean up. This triggered failure of fstests
generic/085. Fix the failure path of btrfs_sb_log_location_bdev() to
call blkdev_put().

Fixes: 12659251ca5df ("btrfs: implement log-structured superblock for ZONED mode")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:47 +01:00
Josef Bacik
8848395975 btrfs: check WRITE_ERR when trying to read an extent buffer
commit 651740a502411793327e2f0741104749c4eedcd1 upstream.

Filipe reported a hang when we have errors on btrfs.  This turned out to
be a side-effect of my fix c2e39305299f01 ("btrfs: clear extent buffer
uptodate when we fail to write it") which made it so we clear
EXTENT_BUFFER_UPTODATE on an eb when we fail to write it out.

Below is a paste of Filipe's analysis he got from using drgn to debug
the hang

"""
btree readahead code calls read_extent_buffer_pages(), sets ->io_pages to
a value while writeback of all pages has not yet completed:
   --> writeback for the first 3 pages finishes, we clear
       EXTENT_BUFFER_UPTODATE from eb on the first page when we get an
       error.
   --> at this point eb->io_pages is 1 and we cleared Uptodate bit from the
       first 3 pages
   --> read_extent_buffer_pages() does not see EXTENT_BUFFER_UPTODATE() so
       it continues, it's able to lock the pages since we obviously don't
       hold the pages locked during writeback
   --> read_extent_buffer_pages() then computes 'num_reads' as 3, and sets
       eb->io_pages to 3, since only the first page does not have Uptodate
       bit set at this point
   --> writeback for the remaining page completes, we ended decrementing
       eb->io_pages by 1, resulting in eb->io_pages == 2, and therefore
       never calling end_extent_buffer_writeback(), so
       EXTENT_BUFFER_WRITEBACK remains in the eb's flags
   --> of course, when the read bio completes, it doesn't and shouldn't
       call end_extent_buffer_writeback()
   --> we should clear EXTENT_BUFFER_UPTODATE only after all pages of
       the eb finished writeback?  or maybe make the read pages code
       wait for writeback of all pages of the eb to complete before
       checking which pages need to be read, touch ->io_pages, submit
       read bio, etc

writeback bit never cleared means we can hang when aborting a
transaction, at:

    btrfs_cleanup_one_transaction()
       btrfs_destroy_marked_extents()
         wait_on_extent_buffer_writeback()
"""

This is a problem because our writes are not synchronized with reads in
any way.  We clear the UPTODATE flag and then we can easily come in and
try to read the EB while we're still waiting on other bio's to
complete.

We have two options here, we could lock all the pages, and then check to
see if eb->io_pages != 0 to know if we've already got an outstanding
write on the eb.

Or we can simply check to see if we have WRITE_ERR set on this extent
buffer.  We set this bit _before_ we clear UPTODATE, so if the read gets
triggered because we aren't UPTODATE because of a write error we're
guaranteed to have WRITE_ERR set, and in this case we can simply return
-EIO.  This will fix the reported hang.

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: c2e39305299f01 ("btrfs: clear extent buffer uptodate when we fail to write it")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:47 +01:00
Filipe Manana
bbdaa7a48f btrfs: fix double free of anon_dev after failure to create subvolume
commit 33fab972497ae66822c0b6846d4f9382938575b6 upstream.

When creating a subvolume, at create_subvol(), we allocate an anonymous
device and later call btrfs_get_new_fs_root(), which in turn just calls
btrfs_get_root_ref(). There we call btrfs_init_fs_root() which assigns
the anonymous device to the root, but if after that call there's an error,
when we jump to 'fail' label, we call btrfs_put_root(), which frees the
anonymous device and then returns an error that is propagated back to
create_subvol(). Than create_subvol() frees the anonymous device again.

When this happens, if the anonymous device was not reallocated after
the first time it was freed with btrfs_put_root(), we get a kernel
message like the following:

  (...)
  [13950.282466] BTRFS: error (device dm-0) in create_subvol:663: errno=-5 IO failure
  [13950.283027] ida_free called for id=65 which is not allocated.
  [13950.285974] BTRFS info (device dm-0): forced readonly
  (...)

If the anonymous device gets reallocated by another btrfs filesystem
or any other kernel subsystem, then bad things can happen.

So fix this by setting the root's anonymous device to 0 at
btrfs_get_root_ref(), before we call btrfs_put_root(), if an error
happened.

Fixes: 2dfb1e43f57dd3 ("btrfs: preallocate anon block device at first phase of snapshot creation")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:47 +01:00
Jianglei Nie
493ff661d4 btrfs: fix memory leak in __add_inode_ref()
commit f35838a6930296fc1988764cfa54cb3f705c0665 upstream.

Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8233bb ("btrfs: Properly handle backref_in_log retval")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:47 +01:00
David Howells
5473fe0c48 afs: Fix mmap
[ Upstream commit 1744a22ae948799da7927b53ec97ccc877ff9d61 ]

Fix afs_add_open_map() to check that the vnode isn't already on the list
when it adds it.  It's possible that afs_drop_open_mmap() decremented
the cb_nr_mmap counter, but hadn't yet got into the locked section to
remove it.

Also vnode->cb_mmap_link should be initialised, so fix that too.

Fixes: 6e0e99d58a65 ("afs: Fix mmap coherency vs 3rd-party changes")
Reported-by: kafs-testing+fedora34_64checkkafs-build-300@auristor.com
Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: kafs-testing+fedora34_64checkkafs-build-300@auristor.com
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/686465.1639435380@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:45 +01:00
Xiubo Li
e7506c76b7 ceph: initialize pathlen variable in reconnect_caps_cb
[ Upstream commit ee2a095d3b24f300a5e11944d208801e928f108c ]

The smatch static checker warned about an uninitialized symbol usage in
this function, in the case where ceph_mdsc_build_path returns an error.

It turns out that that case is harmless, but it just looks sketchy.
Initialize the variable at declaration time, and remove the unneeded
setting of it later.

Fixes: a33f6432b3a6 ("ceph: encode inodes' parent/d_name in cap reconnect message")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:38 +01:00
Hu Weiwen
24a19e6d65 ceph: fix duplicate increment of opened_inodes metric
[ Upstream commit 973e5245637accc4002843f6b888495a6a7762bc ]

opened_inodes is incremented twice when the same inode is opened twice
with O_RDONLY and O_WRONLY respectively.

To reproduce, run this python script, then check the metrics:

import os
for _ in range(10000):
    fd_r = os.open('a', os.O_RDONLY)
    fd_w = os.open('a', os.O_WRONLY)
    os.close(fd_r)
    os.close(fd_w)

Fixes: 1dd8d4708136 ("ceph: metrics for opened files, pinned caps and opened inodes")
Signed-off-by: Hu Weiwen <sehuww@mail.scut.edu.cn>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:38 +01:00
Anand Jain
af9b9c8bfe btrfs: remove stale comment about the btrfs_show_devname
Commit cdccc03a8a369b59cff5e7ea3292511cfa551120 upstream.

There were few lockdep warnings because btrfs_show_devname() was using
device_list_mutex as recorded in the commits:

  0ccd05285e7f ("btrfs: fix a possible umount deadlock")
  779bf3fefa83 ("btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex")

And finally, commit 88c14590cdd6 ("btrfs: use RCU in btrfs_show_devname
for device list traversal") removed the device_list_mutex from
btrfs_show_devname for performance reasons.

This patch removes a stale comment about the function
btrfs_show_devname and device_list_mutex.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:37 +01:00
Anand Jain
a6e7e218a4 btrfs: update latest_dev when we create a sprout device
Commit b7cb29e666fe79dda5dbe5f57fb7c92413bf161c upstream.

When we add a device to the seed filesystem (sprouting) it is a new
filesystem (and fsid) on the device added. Update the latest_dev so
that /proc/self/mounts shows the correct device.

Example:

  $ btrfstune -S1 /dev/vg/seed
  $ mount /dev/vg/seed /btrfs
  mount: /btrfs: WARNING: device write-protected, mounted read-only.

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

  $ btrfs dev add -f /dev/vg/new /btrfs

Before:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

After:

  $ cat /proc/self/mounts | grep btrfs
  /dev/mapper/vg-new /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0

Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:37 +01:00
Anand Jain
e342c25580 btrfs: use latest_dev in btrfs_show_devname
Commit 6605fd2f394bba0a0059df2b6cfc87b0b6d393a2 upstream.

The test case btrfs/238 reports the warning below:

 WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs]
 CPU: 2 PID: 1 Comm: systemd Tainted: G        W  O 5.14.0-rc1-custom #72
 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
   btrfs_show_devname+0x108/0x1b4 [btrfs]
   show_mountinfo+0x234/0x2c4
   m_show+0x28/0x34
   seq_read_iter+0x12c/0x3c4
   vfs_read+0x29c/0x2c8
   ksys_read+0x80/0xec
   __arm64_sys_read+0x28/0x34
   invoke_syscall+0x50/0xf8
   do_el0_svc+0x88/0x138
   el0_svc+0x2c/0x8c
   el0t_64_sync_handler+0x84/0xe4
   el0t_64_sync+0x198/0x19c

Reason:
While btrfs_prepare_sprout() moves the fs_devices::devices into
fs_devices::seed_list, the btrfs_show_devname() searches for the devices
and found none, leading to the warning as in above.

Fix:
latest_dev is updated according to the changes to the device list.
That means we could use the latest_dev->name to show the device name in
/proc/self/mounts, the pointer will be always valid as it's assigned
before the device is deleted from the list in remove or replace.
The RCU protection is sufficient as the device structure is freed after
synchronization.

Reported-by: Su Yue <l@damenly.su>
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:37 +01:00
Anand Jain
5c460192c2 btrfs: convert latest_bdev type to btrfs_device and rename
Commit d24fa5c1da08026be9959baca309fa0adf8708bf upstream.

In preparation to fix a bug in btrfs_show_devname().

Convert fs_devices::latest_bdev type from struct block_device to struct
btrfs_device and, rename the member to fs_devices::latest_dev.
So that btrfs_show_devname() can use fs_devices::latest_dev::name.

Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:37 +01:00
Christian Brauner
09cdb8aa59 ceph: fix up non-directory creation in SGID directories
commit fd84bfdddd169c219c3a637889a8b87f70a072c2 upstream.

Ceph always inherits the SGID bit if it is set on the parent inode,
while the generic inode_init_owner does not do this in a few cases where
it can create a possible security problem (cf. [1]).

Update ceph to strip the SGID bit just as inode_init_owner would.

This bug was detected by the mapped mount testsuite in [3]. The
testsuite tests all core VFS functionality and semantics with and
without mapped mounts. That is to say it functions as a generic VFS
testsuite in addition to a mapped mount testsuite. While working on
mapped mount support for ceph, SIGD inheritance was the only failing
test for ceph after the port.

The same bug was detected by the mapped mount testsuite in XFS in
January 2021 (cf. [2]).

[1]: commit 0fa3ecd87848 ("Fix up non-directory creation in SGID directories")
[2]: commit 01ea173e103e ("xfs: fix up non-directory creation in SGID directories")
[3]: https://git.kernel.org/fs/xfs/xfstests-dev.git

Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22 09:32:36 +01:00
Miklos Szeredi
5b4a8fbe4b fuse: make sure reclaim doesn't write the inode
commit 5c791fe1e2a4f401f819065ea4fc0450849f1818 upstream.

In writeback cache mode mtime/ctime updates are cached, and flushed to the
server using the ->write_inode() callback.

Closing the file will result in a dirty inode being immediately written,
but in other cases the inode can remain dirty after all references are
dropped.  This result in the inode being written back from reclaim, which
can deadlock on a regular allocation while the request is being served.

The usual mechanisms (GFP_NOFS/PF_MEMALLOC*) don't work for FUSE, because
serving a request involves unrelated userspace process(es).

Instead do the same as for dirty pages: make sure the inode is written
before the last reference is gone.

 - fallocate(2)/copy_file_range(2): these call file_update_time() or
   file_modified(), so flush the inode before returning from the call

 - unlink(2), link(2) and rename(2): these call fuse_update_ctime(), so
   flush the ctime directly from this helper

Reported-by: chenguanyou <chenguanyou@xiaomi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Ed Tsai <ed.tsai@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17 10:30:16 +01:00
David Howells
1ac287b7b6 netfs: Fix lockdep warning from taking sb_writers whilst holding mmap_lock
[ Upstream commit 598ad0bd09329818ee041cb3e4b60ba0a70cb1ee ]

Taking sb_writers whilst holding mmap_lock isn't allowed and will result in
a lockdep warning like that below.  The problem comes from cachefiles
needing to take the sb_writers lock in order to do a write to the cache,
but being asked to do this by netfslib called from readpage, readahead or
write_begin[1].

Fix this by always offloading the write to the cache off to a worker
thread.  The main thread doesn't need to wait for it, so deadlock can be
avoided.

This can be tested by running the quick xfstests on something like afs or
ceph with lockdep enabled.

WARNING: possible circular locking dependency detected
5.15.0-rc1-build2+ #292 Not tainted
------------------------------------------------------
holetest/65517 is trying to acquire lock:
ffff88810c81d730 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_fault+0x276/0x7a5

but task is already holding lock:
ffff8881595b53e8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x28d/0x59c

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&mm->mmap_lock#2){++++}-{3:3}:
       validate_chain+0x3c4/0x4a8
       __lock_acquire+0x89d/0x949
       lock_acquire+0x2dc/0x34b
       __might_fault+0x87/0xb1
       strncpy_from_user+0x25/0x18c
       removexattr+0x7c/0xe5
       __do_sys_fremovexattr+0x73/0x96
       do_syscall_64+0x67/0x7a
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (sb_writers#10){.+.+}-{0:0}:
       validate_chain+0x3c4/0x4a8
       __lock_acquire+0x89d/0x949
       lock_acquire+0x2dc/0x34b
       cachefiles_write+0x2b3/0x4bb
       netfs_rreq_do_write_to_cache+0x3b5/0x432
       netfs_readpage+0x2de/0x39d
       filemap_read_page+0x51/0x94
       filemap_get_pages+0x26f/0x413
       filemap_read+0x182/0x427
       new_sync_read+0xf0/0x161
       vfs_read+0x118/0x16e
       ksys_read+0xb8/0x12e
       do_syscall_64+0x67/0x7a
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (mapping.invalidate_lock#3){.+.+}-{3:3}:
       check_noncircular+0xe4/0x129
       check_prev_add+0x16b/0x3a4
       validate_chain+0x3c4/0x4a8
       __lock_acquire+0x89d/0x949
       lock_acquire+0x2dc/0x34b
       down_read+0x40/0x4a
       filemap_fault+0x276/0x7a5
       __do_fault+0x96/0xbf
       do_fault+0x262/0x35a
       __handle_mm_fault+0x171/0x1b5
       handle_mm_fault+0x12a/0x233
       do_user_addr_fault+0x3d2/0x59c
       exc_page_fault+0x85/0xa5
       asm_exc_page_fault+0x1e/0x30

other info that might help us debug this:

Chain exists of:
  mapping.invalidate_lock#3 --> sb_writers#10 --> &mm->mmap_lock#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_lock#2);
                               lock(sb_writers#10);
                               lock(&mm->mmap_lock#2);
  lock(mapping.invalidate_lock#3);

 *** DEADLOCK ***

1 lock held by holetest/65517:
 #0: ffff8881595b53e8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x28d/0x59c

stack backtrace:
CPU: 0 PID: 65517 Comm: holetest Not tainted 5.15.0-rc1-build2+ #292
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
 dump_stack_lvl+0x45/0x59
 check_noncircular+0xe4/0x129
 ? print_circular_bug+0x207/0x207
 ? validate_chain+0x461/0x4a8
 ? add_chain_block+0x88/0xd9
 ? hlist_add_head_rcu+0x49/0x53
 check_prev_add+0x16b/0x3a4
 validate_chain+0x3c4/0x4a8
 ? check_prev_add+0x3a4/0x3a4
 ? mark_lock+0xa5/0x1c6
 __lock_acquire+0x89d/0x949
 lock_acquire+0x2dc/0x34b
 ? filemap_fault+0x276/0x7a5
 ? rcu_read_unlock+0x59/0x59
 ? add_to_page_cache_lru+0x13c/0x13c
 ? lock_is_held_type+0x7b/0xd3
 down_read+0x40/0x4a
 ? filemap_fault+0x276/0x7a5
 filemap_fault+0x276/0x7a5
 ? pagecache_get_page+0x2dd/0x2dd
 ? __lock_acquire+0x8bc/0x949
 ? pte_offset_kernel.isra.0+0x6d/0xc3
 __do_fault+0x96/0xbf
 ? do_fault+0x124/0x35a
 do_fault+0x262/0x35a
 ? handle_pte_fault+0x1c1/0x20d
 __handle_mm_fault+0x171/0x1b5
 ? handle_pte_fault+0x20d/0x20d
 ? __lock_release+0x151/0x254
 ? mark_held_locks+0x1f/0x78
 ? rcu_read_unlock+0x3a/0x59
 handle_mm_fault+0x12a/0x233
 do_user_addr_fault+0x3d2/0x59c
 ? pgtable_bad+0x70/0x70
 ? rcu_read_lock_bh_held+0xab/0xab
 exc_page_fault+0x85/0xa5
 ? asm_exc_page_fault+0x8/0x30
 asm_exc_page_fault+0x1e/0x30
RIP: 0033:0x40192f
Code: ff 48 89 c3 48 8b 05 50 28 00 00 48 85 ed 7e 23 31 d2 4b 8d 0c 2f eb 0a 0f 1f 00 48 8b 05 39 28 00 00 48 0f af c2 48 83 c2 01 <48> 89 1c 01 48 39 d5 7f e8 8b 0d f2 27 00 00 31 c0 85 c9 74 0e 8b
RSP: 002b:00007f9931867eb0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00007f9931868700 RCX: 00007f993206ac00
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00007ffc13e06ee0
RBP: 0000000000000100 R08: 0000000000000000 R09: 00007f9931868700
R10: 00007f99318689d0 R11: 0000000000000202 R12: 00007ffc13e06ee0
R13: 0000000000000c00 R14: 00007ffc13e06e00 R15: 00007f993206a000

Fixes: 726218fdc22c ("netfs: Define an interface to talk to a cache")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
cc: Jan Kara <jack@suse.cz>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20210922110420.GA21576@quack2.suse.cz/ [1]
Link: https://lore.kernel.org/r/163887597541.1596626.2668163316598972956.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-17 10:30:13 +01:00
Xie Yongji
4a7c655064 aio: Fix incorrect usage of eventfd_signal_allowed()
commit 4b3749865374899e115aa8c48681709b086fe6d3 upstream.

We should defer eventfd_signal() to the workqueue when
eventfd_signal_allowed() return false rather than return
true.

Fixes: b542e383d8c0 ("eventfd: Make signal recursion protection a task bit")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210913111928.98-1-xieyongji@bytedance.com
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:22 +01:00
Steven Rostedt (VMware)
23a5f9797d tracefs: Set all files to the same group ownership as the mount option
commit 48b27b6b5191e2e1f2798cd80877b6e4ef47c351 upstream.

As people have been asking to allow non-root processes to have access to
the tracefs directory, it was considered best to only allow groups to have
access to the directory, where it is easier to just set the tracefs file
system to a specific group (as other would be too dangerous), and that way
the admins could pick which processes would have access to tracefs.

Unfortunately, this broke tooling on Android that expected the other bit
to be set. For some special cases, for non-root tools to trace the system,
tracefs would be mounted and change the permissions of the top level
directory which gave access to all running tasks permission to the
tracing directory. Even though this would be dangerous to do in a
production environment, for testing environments this can be useful.

Now with the new changes to not allow other (which is still the proper
thing to do), it breaks the testing tooling. Now more code needs to be
loaded on the system to change ownership of the tracing directory.

The real solution is to have tracefs honor the gid=xxx option when
mounting. That is,

(tracing group tracing has value 1003)

 mount -t tracefs -o gid=1003 tracefs /sys/kernel/tracing

should have it that all files in the tracing directory should be of the
given group.

Copy the logic from d_walk() from dcache.c and simplify it for the mount
case of tracefs if gid is set. All the files in tracefs will be walked and
their group will be set to the value passed in.

Link: https://lkml.kernel.org/r/20211207171729.2a54e1b3@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: Yabin Cui <yabinc@google.com>
Fixes: 49d67e445742 ("tracefs: Have tracefs directories not set OTH permission bits by default")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:15 +01:00
Eric Biggers
60d311f9e6 aio: fix use-after-free due to missing POLLFREE handling
commit 50252e4b5e989ce64555c7aef7516bdefc2fea72 upstream.

signalfd_poll() and binder_poll() are special in that they use a
waitqueue whose lifetime is the current task, rather than the struct
file as is normally the case.  This is okay for blocking polls, since a
blocking poll occurs within one task; however, non-blocking polls
require another solution.  This solution is for the queue to be cleared
before it is freed, by sending a POLLFREE notification to all waiters.

Unfortunately, only eventpoll handles POLLFREE.  A second type of
non-blocking poll, aio poll, was added in kernel v4.18, and it doesn't
handle POLLFREE.  This allows a use-after-free to occur if a signalfd or
binder fd is polled with aio poll, and the waitqueue gets freed.

Fix this by making aio poll handle POLLFREE.

A patch by Ramji Jiyani <ramjiyani@google.com>
(https://lore.kernel.org/r/20211027011834.2497484-1-ramjiyani@google.com)
tried to do this by making aio_poll_wake() always complete the request
inline if POLLFREE is seen.  However, that solution had two bugs.
First, it introduced a deadlock, as it unconditionally locked the aio
context while holding the waitqueue lock, which inverts the normal
locking order.  Second, it didn't consider that POLLFREE notifications
are missed while the request has been temporarily de-queued.

The second problem was solved by my previous patch.  This patch then
properly fixes the use-after-free by handling POLLFREE in a
deadlock-free way.  It does this by taking advantage of the fact that
freeing of the waitqueue is RCU-delayed, similar to what eventpoll does.

Fixes: 2c14fa838cbe ("aio: implement IOCB_CMD_POLL")
Cc: <stable@vger.kernel.org> # v4.18+
Link: https://lore.kernel.org/r/20211209010455.42744-6-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:15 +01:00
Eric Biggers
924f51534d aio: keep poll requests on waitqueue until completed
commit 363bee27e25804d8981dd1c025b4ad49dc39c530 upstream.

Currently, aio_poll_wake() will always remove the poll request from the
waitqueue.  Then, if aio_poll_complete_work() sees that none of the
polled events are ready and the request isn't cancelled, it re-adds the
request to the waitqueue.  (This can easily happen when polling a file
that doesn't pass an event mask when waking up its waitqueue.)

This is fundamentally broken for two reasons:

  1. If a wakeup occurs between vfs_poll() and the request being
     re-added to the waitqueue, it will be missed because the request
     wasn't on the waitqueue at the time.  Therefore, IOCB_CMD_POLL
     might never complete even if the polled file is ready.

  2. When the request isn't on the waitqueue, there is no way to be
     notified that the waitqueue is being freed (which happens when its
     lifetime is shorter than the struct file's).  This is supposed to
     happen via the waitqueue entries being woken up with POLLFREE.

Therefore, leave the requests on the waitqueue until they are actually
completed (or cancelled).  To keep track of when aio_poll_complete_work
needs to be scheduled, use new fields in struct poll_iocb.  Remove the
'done' field which is now redundant.

Note that this is consistent with how sys_poll() and eventpoll work;
their wakeup functions do *not* remove the waitqueue entries.

Fixes: 2c14fa838cbe ("aio: implement IOCB_CMD_POLL")
Cc: <stable@vger.kernel.org> # v4.18+
Link: https://lore.kernel.org/r/20211209010455.42744-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:15 +01:00
Eric Biggers
8d6760fd5d signalfd: use wake_up_pollfree()
commit 9537bae0da1f8d1e2361ab6d0479e8af7824e160 upstream.

wake_up_poll() uses nr_exclusive=1, so it's not guaranteed to wake up
all exclusive waiters.  Yet, POLLFREE *must* wake up all waiters.  epoll
and aio poll are fortunately not affected by this, but it's very
fragile.  Thus, the new function wake_up_pollfree() has been introduced.

Convert signalfd to use wake_up_pollfree().

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: d80e731ecab4 ("epoll: introduce POLLFREE to flush ->signalfd_wqh before kfree()")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211209010455.42744-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:15 +01:00
Jens Axboe
8e12976c0c io_uring: ensure task_work gets run as part of cancelations
commit 78a780602075d8b00c98070fa26e389b3b3efa72 upstream.

If we successfully cancel a work item but that work item needs to be
processed through task_work, then we can be sleeping uninterruptibly
in io_uring_cancel_generic() and never process it. Hence we don't
make forward progress and we end up with an uninterruptible sleep
warning.

While in there, correct a comment that should be IFF, not IIF.

Reported-and-tested-by: syzbot+21e6887c0be14181206d@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:15 +01:00
Steven Rostedt (VMware)
041aae47b0 tracefs: Have new files inherit the ownership of their parent
commit ee7f3666995d8537dec17b1d35425f28877671a9 upstream.

If directories in tracefs have their ownership changed, then any new files
and directories that are created under those directories should inherit
the ownership of the director they are created in.

Link: https://lkml.kernel.org/r/20211208075720.4855d180@gandalf.local.home

Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yabin Cui <yabinc@google.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: stable@vger.kernel.org
Fixes: 4282d60689d4f ("tracefs: Add new tracefs file system")
Reported-by: Kalesh Singh <kaleshsingh@google.com>
Reported: https://lore.kernel.org/all/CAC_TJve8MMAv+H_NdLSJXZUSoxOEq2zB_pVaJ9p=7H6Bu3X76g@mail.gmail.com/
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:14 +01:00
Alexander Sverdlin
8bf902fee5 nfsd: Fix nsfd startup race (again)
commit b10252c7ae9c9d7c90552f88b544a44ee773af64 upstream.

Commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first")
has re-opened rpc_pipefs_event() race against nfsd_net_id registration
(register_pernet_subsys()) which has been fixed by commit bb7ffbf29e76
("nfsd: fix nsfd startup race triggering BUG_ON").

Restore the order of register_pernet_subsys() vs register_cld_notifier().
Add WARN_ON() to prevent a future regression.

Crash info:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000012
CPU: 8 PID: 345 Comm: mount Not tainted 5.4.144-... #1
pc : rpc_pipefs_event+0x54/0x120 [nfsd]
lr : rpc_pipefs_event+0x48/0x120 [nfsd]
Call trace:
 rpc_pipefs_event+0x54/0x120 [nfsd]
 blocking_notifier_call_chain
 rpc_fill_super
 get_tree_keyed
 rpc_fs_get_tree
 vfs_get_tree
 do_mount
 ksys_mount
 __arm64_sys_mount
 el0_svc_handler
 el0_svc

Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:14 +01:00
J. Bruce Fields
148c816f10 nfsd: fix use-after-free due to delegation race
commit 548ec0805c399c65ed66c6641be467f717833ab5 upstream.

A delegation break could arrive as soon as we've called vfs_setlease.  A
delegation break runs a callback which immediately (in
nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru.  If we
then exit nfs4_set_delegation without hashing the delegation, it will be
freed as soon as the callback is done with it, without ever being
removed from del_recall_lru.

Symptoms show up later as use-after-free or list corruption warnings,
usually in the laundromat thread.

I suspect aba2072f4523 "nfsd: grant read delegations to clients holding
writes" made this bug easier to hit, but I looked as far back as v3.0
and it looks to me it already had the same problem.  So I'm not sure
where the bug was introduced; it may have been there from the beginning.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:14 +01:00
Johannes Thumshirn
ca06c5cb1b btrfs: free exchange changeset on failures
commit da5e817d9d75422eaaa05490d0b9a5e328fc1a51 upstream.

Fstests runs on my VMs have show several kmemleak reports like the following.

  unreferenced object 0xffff88811ae59080 (size 64):
    comm "xfs_io", pid 12124, jiffies 4294987392 (age 6.368s)
    hex dump (first 32 bytes):
      00 c0 1c 00 00 00 00 00 ff cf 1c 00 00 00 00 00  ................
      90 97 e5 1a 81 88 ff ff 90 97 e5 1a 81 88 ff ff  ................
    backtrace:
      [<00000000ac0176d2>] ulist_add_merge+0x60/0x150 [btrfs]
      [<0000000076e9f312>] set_state_bits+0x86/0xc0 [btrfs]
      [<0000000014fe73d6>] set_extent_bit+0x270/0x690 [btrfs]
      [<000000004f675208>] set_record_extent_bits+0x19/0x20 [btrfs]
      [<00000000b96137b1>] qgroup_reserve_data+0x274/0x310 [btrfs]
      [<0000000057e9dcbb>] btrfs_check_data_free_space+0x5c/0xa0 [btrfs]
      [<0000000019c4511d>] btrfs_delalloc_reserve_space+0x1b/0xa0 [btrfs]
      [<000000006d37e007>] btrfs_dio_iomap_begin+0x415/0x970 [btrfs]
      [<00000000fb8a74b8>] iomap_iter+0x161/0x1e0
      [<0000000071dff6ff>] __iomap_dio_rw+0x1df/0x700
      [<000000002567ba53>] iomap_dio_rw+0x5/0x20
      [<0000000072e555f8>] btrfs_file_write_iter+0x290/0x530 [btrfs]
      [<000000005eb3d845>] new_sync_write+0x106/0x180
      [<000000003fb505bf>] vfs_write+0x24d/0x2f0
      [<000000009bb57d37>] __x64_sys_pwrite64+0x69/0xa0
      [<000000003eba3fdf>] do_syscall_64+0x43/0x90

In case brtfs_qgroup_reserve_data() or btrfs_delalloc_reserve_metadata()
fail the allocated extent_changeset will not be freed.

So in btrfs_check_data_free_space() and btrfs_delalloc_reserve_space()
free the allocated extent_changeset to get rid of the allocated memory.

The issue currently only happens in the direct IO write path, but only
after 65b3c08606e5 ("btrfs: fix ENOSPC failure when attempting direct IO
write into NOCOW range"), and also at defrag_one_locked_target(). Every
other place is always calling extent_changeset_free() even if its call
to btrfs_delalloc_reserve_space() or btrfs_check_data_free_space() has
failed.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:13 +01:00
Qu Wenruo
32d4054cb3 btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling
commit 8289ed9f93bef2762f9184e136d994734b16d997 upstream.

I hit the BUG_ON() with generic/475 test case, and to my surprise, all
callers of btrfs_del_root_ref() are already aborting transaction, thus
there is not need for such BUG_ON(), just go to @out label and caller
will properly handle the error.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:13 +01:00
Naohiro Aota
477675049c btrfs: fix re-dirty process of tree-log nodes
commit 84c25448929942edacba905cecc0474e91114e7a upstream.

There is a report of a transaction abort of -EAGAIN with the following
script.

  #!/bin/sh

  for d in sda sdb; do
          mkfs.btrfs -d single -m single -f /dev/\${d}
  done

  mount /dev/sda /mnt/test
  mount /dev/sdb /mnt/scratch

  for dir in test scratch; do
          echo 3 >/proc/sys/vm/drop_caches
          fio --directory=/mnt/\${dir} --name=fio.\${dir} --rw=read --size=50G --bs=64m \
                  --numjobs=$(nproc) --time_based --ramp_time=5 --runtime=480 \
                  --group_reporting |& tee /dev/shm/fio.\${dir}
          echo 3 >/proc/sys/vm/drop_caches
  done

  for d in sda sdb; do
          umount /dev/\${d}
  done

The stack trace is shown in below.

  [3310.967991] BTRFS: error (device sda) in btrfs_commit_transaction:2341: errno=-11 unknown (Error while writing out transaction)
  [3310.968060] BTRFS info (device sda): forced readonly
  [3310.968064] BTRFS warning (device sda): Skipping commit of aborted transaction.
  [3310.968065] ------------[ cut here ]------------
  [3310.968066] BTRFS: Transaction aborted (error -11)
  [3310.968074] WARNING: CPU: 14 PID: 1684 at fs/btrfs/transaction.c:1946 btrfs_commit_transaction.cold+0x209/0x2c8
  [3310.968131] CPU: 14 PID: 1684 Comm: fio Not tainted 5.14.10-300.fc35.x86_64 #1
  [3310.968135] Hardware name: DIAWAY Tartu/Tartu, BIOS V2.01.B10 04/08/2021
  [3310.968137] RIP: 0010:btrfs_commit_transaction.cold+0x209/0x2c8
  [3310.968144] RSP: 0018:ffffb284ce393e10 EFLAGS: 00010282
  [3310.968147] RAX: 0000000000000026 RBX: ffff973f147b0f60 RCX: 0000000000000027
  [3310.968149] RDX: ffff974ecf098a08 RSI: 0000000000000001 RDI: ffff974ecf098a00
  [3310.968150] RBP: ffff973f147b0f08 R08: 0000000000000000 R09: ffffb284ce393c48
  [3310.968151] R10: ffffb284ce393c40 R11: ffffffff84f47468 R12: ffff973f101bfc00
  [3310.968153] R13: ffff971f20cf2000 R14: 00000000fffffff5 R15: ffff973f147b0e58
  [3310.968154] FS:  00007efe65468740(0000) GS:ffff974ecf080000(0000) knlGS:0000000000000000
  [3310.968157] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [3310.968158] CR2: 000055691bcbe260 CR3: 000000105cfa4001 CR4: 0000000000770ee0
  [3310.968160] PKRU: 55555554
  [3310.968161] Call Trace:
  [3310.968167]  ? dput+0xd4/0x300
  [3310.968174]  btrfs_sync_file+0x3f1/0x490
  [3310.968180]  __x64_sys_fsync+0x33/0x60
  [3310.968185]  do_syscall_64+0x3b/0x90
  [3310.968190]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [3310.968194] RIP: 0033:0x7efe6557329b
  [3310.968200] RSP: 002b:00007ffe0236ebc0 EFLAGS: 00000293 ORIG_RAX: 000000000000004a
  [3310.968203] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efe6557329b
  [3310.968204] RDX: 0000000000000000 RSI: 00007efe58d77010 RDI: 0000000000000006
  [3310.968205] RBP: 0000000004000000 R08: 0000000000000000 R09: 00007efe58d77010
  [3310.968207] R10: 0000000016cacc0c R11: 0000000000000293 R12: 00007efe5ce95980
  [3310.968208] R13: 0000000000000000 R14: 00007efe6447c790 R15: 0000000c80000000
  [3310.968212] ---[ end trace 1a346f4d3c0d96ba ]---
  [3310.968214] BTRFS: error (device sda) in cleanup_transaction:1946: errno=-11 unknown

The abort occurs because of a write hole while writing out freeing tree
nodes of a tree-log tree. For zoned btrfs, we re-dirty a freed tree
node to ensure btrfs can write the region and does not leave a hole on
write on a zoned device. The current code fails to re-dirty a node
when the tree-log tree's depth is greater or equal to 2. That leads to
a transaction abort with -EAGAIN.

Fix the issue by properly re-dirtying a node on walking up the tree.

Fixes: d3575156f662 ("btrfs: zoned: redirty released extent buffers")
CC: stable@vger.kernel.org # 5.12+
Link: https://github.com/kdave/btrfs-progs/issues/415
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:12 +01:00
Josef Bacik
0338e448b9 btrfs: clear extent buffer uptodate when we fail to write it
commit c2e39305299f0118298c2201f6d6cc7d3485f29e upstream.

I got dmesg errors on generic/281 on our overnight fstests.  Looking at
the history this happens occasionally, with errors like this

  WARNING: CPU: 0 PID: 673217 at fs/btrfs/extent_io.c:6848 assert_eb_page_uptodate+0x3f/0x50
  CPU: 0 PID: 673217 Comm: kworker/u4:13 Tainted: G        W         5.16.0-rc2+ #469
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Workqueue: btrfs-cache btrfs_work_helper
  RIP: 0010:assert_eb_page_uptodate+0x3f/0x50
  RSP: 0018:ffffae598230bc60 EFLAGS: 00010246
  RAX: 0017ffffc0002112 RBX: ffffebaec4100900 RCX: 0000000000001000
  RDX: ffffebaec45733c7 RSI: ffffebaec4100900 RDI: ffff9fd98919f340
  RBP: 0000000000000d56 R08: ffff9fd98e300000 R09: 0000000000000000
  R10: 0001207370a91c50 R11: 0000000000000000 R12: 00000000000007b0
  R13: ffff9fd98919f340 R14: 0000000001500000 R15: 0000000001cb0000
  FS:  0000000000000000(0000) GS:ffff9fd9fbc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f549fcf8940 CR3: 0000000114908004 CR4: 0000000000370ef0
  Call Trace:

   extent_buffer_test_bit+0x3f/0x70
   free_space_test_bit+0xa6/0xc0
   load_free_space_tree+0x1d6/0x430
   caching_thread+0x454/0x630
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? lock_release+0x1f0/0x2d0
   btrfs_work_helper+0xf2/0x3e0
   ? lock_release+0x1f0/0x2d0
   ? finish_task_switch.isra.0+0xf9/0x3a0
   process_one_work+0x270/0x5a0
   worker_thread+0x55/0x3c0
   ? process_one_work+0x5a0/0x5a0
   kthread+0x174/0x1a0
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x1f/0x30

This happens because we're trying to read from a extent buffer page that
is !PageUptodate.  This happens because we will clear the page uptodate
when we have an IO error, but we don't clear the extent buffer uptodate.
If we do a read later and find this extent buffer we'll think its valid
and not return an error, and then trip over this warning.

Fix this by also clearing uptodate on the extent buffer when this
happens, so that we get an error when we do a btrfs_search_slot() and
find this block later.

CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:12 +01:00
Vincent Whitchurch
d14bad8c11 cifs: Fix crash on unload of cifs_arc4.ko
commit 51a08bdeca27988a17c87b87d8e64ffecbd2a172 upstream.

The exit function is wrongly placed in the __init section and this leads
to a crash when the module is unloaded.  Just remove both the init and
exit functions since this module does not need them.

Fixes: 71c02863246167b3d ("cifs: fork arc4 and create a separate module...")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.15
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:12 +01:00
Jens Axboe
690637ec04 io-wq: don't retry task_work creation failure on fatal conditions
[ Upstream commit a226abcd5d427fe9d42efc442818a4a1821e2664 ]

We don't want to be retrying task_work creation failure if there's
an actual signal pending for the parent task. If we do, then we can
enter an infinite loop of perpetually retrying and each retry failing
with -ERESTARTNOINTR because a signal is pending.

Fixes: 3146cba99aa2 ("io-wq: make worker creation resilient against signals")
Reported-by: Florian Fischer <florian.fl.fischer@fau.de>
Link: https://lore.kernel.org/io-uring/20211202165606.mqryio4yzubl7ms5@pasture/
Tested-by: Florian Fischer <florian.fl.fischer@fau.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08 09:04:53 +01:00
Linus Torvalds
6fe4eadd54 fget: check that the fd still exists after getting a ref to it
commit 054aa8d439b9185d4f5eb9a90282d1ce74772969 upstream.

Jann Horn points out that there is another possible race wrt Unix domain
socket garbage collection, somewhat reminiscent of the one fixed in
commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK").

See the extended comment about the garbage collection requirements added
to unix_peek_fds() by that commit for details.

The race comes from how we can locklessly look up a file descriptor just
as it is in the process of being closed, and with the right artificial
timing (Jann added a few strategic 'mdelay(500)' calls to do that), the
Unix domain socket garbage collector could see the reference count
decrement of the close() happen before fget() took its reference to the
file and the file was attached onto a new file descriptor.

This is all (intentionally) correct on the 'struct file *' side, with
RCU lookups and lockless reference counting very much part of the
design.  Getting that reference count out of order isn't a problem per
se.

But the garbage collector can get confused by seeing this situation of
having seen a file not having any remaining external references and then
seeing it being attached to an fd.

In commit cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK") the
fix was to serialize the file descriptor install with the garbage
collector by taking and releasing the unix_gc_lock.

That's not really an option here, but since this all happens when we are
in the process of looking up a file descriptor, we can instead simply
just re-check that the file hasn't been closed in the meantime, and just
re-do the lookup if we raced with a concurrent close() of the same file
descriptor.

Reported-and-tested-by: Jann Horn <jannh@google.com>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:04:42 +01:00
Wang Yugui
7440613439 btrfs: check-integrity: fix a warning on write caching disabled disk
[ Upstream commit a91cf0ffbc244792e0b3ecf7d0fddb2f344b461f ]

When a disk has write caching disabled, we skip submission of a bio with
flush and sync requests before writing the superblock, since it's not
needed. However when the integrity checker is enabled, this results in
reports that there are metadata blocks referred by a superblock that
were not properly flushed. So don't skip the bio submission only when
the integrity checker is enabled for the sake of simplicity, since this
is a debug tool and not meant for use in non-debug builds.

fstests/btrfs/220 trigger a check-integrity warning like the following
when CONFIG_BTRFS_FS_CHECK_INTEGRITY=y and the disk with WCE=0.

  btrfs: attempt to write superblock which references block M @5242880 (sdb2/5242880/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)!
  ------------[ cut here ]------------
  WARNING: CPU: 28 PID: 843680 at fs/btrfs/check-integrity.c:2196 btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  CPU: 28 PID: 843680 Comm: umount Not tainted 5.15.0-0.rc5.39.el8.x86_64 #1
  Hardware name: Dell Inc. Precision T7610/0NK70N, BIOS A18 09/11/2019
  RIP: 0010:btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  RSP: 0018:ffffb642afb47940 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
  RDX: 00000000ffffffff RSI: ffff8b722fc97d00 RDI: ffff8b722fc97d00
  RBP: ffff8b5601c00000 R08: 0000000000000000 R09: c0000000ffff7fff
  R10: 0000000000000001 R11: ffffb642afb476f8 R12: ffffffffffffffff
  R13: ffffb642afb47974 R14: ffff8b5499254c00 R15: 0000000000000003
  FS:  00007f00a06d4080(0000) GS:ffff8b722fc80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fff5cff5ff0 CR3: 00000001c0c2a006 CR4: 00000000001706e0
  Call Trace:
   btrfsic_process_written_block+0x2f7/0x850 [btrfs]
   __btrfsic_submit_bio.part.19+0x310/0x330 [btrfs]
   ? bio_associate_blkg_from_css+0xa4/0x2c0
   btrfsic_submit_bio+0x18/0x30 [btrfs]
   write_dev_supers+0x81/0x2a0 [btrfs]
   ? find_get_pages_range_tag+0x219/0x280
   ? pagevec_lookup_range_tag+0x24/0x30
   ? __filemap_fdatawait_range+0x6d/0xf0
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   ? find_first_extent_bit+0x9b/0x160 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   write_all_supers+0x1b3/0xa70 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   btrfs_commit_transaction+0x59d/0xac0 [btrfs]
   close_ctree+0x11d/0x339 [btrfs]
   generic_shutdown_super+0x71/0x110
   kill_anon_super+0x14/0x30
   btrfs_kill_super+0x12/0x20 [btrfs]
   deactivate_locked_super+0x31/0x70
   cleanup_mnt+0xb8/0x140
   task_work_run+0x6d/0xb0
   exit_to_user_mode_prepare+0x1f0/0x200
   syscall_exit_to_user_mode+0x12/0x30
   do_syscall_64+0x46/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f009f711dfb
  RSP: 002b:00007fff5cff7928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
  RAX: 0000000000000000 RBX: 000055b68c6c9970 RCX: 00007f009f711dfb
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055b68c6c9b50
  RBP: 0000000000000000 R08: 000055b68c6ca900 R09: 00007f009f795580
  R10: 0000000000000000 R11: 0000000000000246 R12: 000055b68c6c9b50
  R13: 00007f00a04bf184 R14: 0000000000000000 R15: 00000000ffffffff
  ---[ end trace 2c4b82abcef9eec4 ]---
  S-65536(sdb2/65536/1)
   -->
  M-1064960(sdb2/1064960/1)

Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08 09:04:39 +01:00
Filipe Manana
e26605497f btrfs: silence lockdep when reading chunk tree during mount
[ Upstream commit 4d9380e0da7be2351437cdac71673a9cd94e50fd ]

Often some test cases like btrfs/161 trigger lockdep splats that complain
about possible unsafe lock scenario due to the fact that during mount,
when reading the chunk tree we end up calling blkdev_get_by_path() while
holding a read lock on a leaf of the chunk tree. That produces a lockdep
splat like the following:

[ 3653.683975] ======================================================
[ 3653.685148] WARNING: possible circular locking dependency detected
[ 3653.686301] 5.15.0-rc7-btrfs-next-103 #1 Not tainted
[ 3653.687239] ------------------------------------------------------
[ 3653.688400] mount/447465 is trying to acquire lock:
[ 3653.689320] ffff8c6b0c76e528 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.691054]
               but task is already holding lock:
[ 3653.692155] ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.693978]
               which lock already depends on the new lock.

[ 3653.695510]
               the existing dependency chain (in reverse order) is:
[ 3653.696915]
               -> #3 (btrfs-chunk-00){++++}-{3:3}:
[ 3653.698053]        down_read_nested+0x4b/0x140
[ 3653.698893]        __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.699988]        btrfs_read_lock_root_node+0x31/0x40 [btrfs]
[ 3653.701205]        btrfs_search_slot+0x537/0xc00 [btrfs]
[ 3653.702234]        btrfs_insert_empty_items+0x32/0x70 [btrfs]
[ 3653.703332]        btrfs_init_new_device+0x563/0x15b0 [btrfs]
[ 3653.704439]        btrfs_ioctl+0x2110/0x3530 [btrfs]
[ 3653.705405]        __x64_sys_ioctl+0x83/0xb0
[ 3653.706215]        do_syscall_64+0x3b/0xc0
[ 3653.706990]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.708040]
               -> #2 (sb_internal#2){.+.+}-{0:0}:
[ 3653.708994]        lock_release+0x13d/0x4a0
[ 3653.709533]        up_write+0x18/0x160
[ 3653.710017]        btrfs_sync_file+0x3f3/0x5b0 [btrfs]
[ 3653.710699]        __loop_update_dio+0xbd/0x170 [loop]
[ 3653.711360]        lo_ioctl+0x3b1/0x8a0 [loop]
[ 3653.711929]        block_ioctl+0x48/0x50
[ 3653.712442]        __x64_sys_ioctl+0x83/0xb0
[ 3653.712991]        do_syscall_64+0x3b/0xc0
[ 3653.713519]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.714233]
               -> #1 (&lo->lo_mutex){+.+.}-{3:3}:
[ 3653.715026]        __mutex_lock+0x92/0x900
[ 3653.715648]        lo_open+0x28/0x60 [loop]
[ 3653.716275]        blkdev_get_whole+0x28/0x90
[ 3653.716867]        blkdev_get_by_dev.part.0+0x142/0x320
[ 3653.717537]        blkdev_open+0x5e/0xa0
[ 3653.718043]        do_dentry_open+0x163/0x390
[ 3653.718604]        path_openat+0x3f0/0xa80
[ 3653.719128]        do_filp_open+0xa9/0x150
[ 3653.719652]        do_sys_openat2+0x97/0x160
[ 3653.720197]        __x64_sys_openat+0x54/0x90
[ 3653.720766]        do_syscall_64+0x3b/0xc0
[ 3653.721285]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.721986]
               -> #0 (&disk->open_mutex){+.+.}-{3:3}:
[ 3653.722775]        __lock_acquire+0x130e/0x2210
[ 3653.723348]        lock_acquire+0xd7/0x310
[ 3653.723867]        __mutex_lock+0x92/0x900
[ 3653.724394]        blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.725041]        blkdev_get_by_path+0xb8/0xd0
[ 3653.725614]        btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
[ 3653.726332]        open_fs_devices+0xd7/0x2c0 [btrfs]
[ 3653.726999]        btrfs_read_chunk_tree+0x3ad/0x870 [btrfs]
[ 3653.727739]        open_ctree+0xb8e/0x17bf [btrfs]
[ 3653.728384]        btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 3653.729130]        legacy_get_tree+0x30/0x50
[ 3653.729676]        vfs_get_tree+0x28/0xc0
[ 3653.730192]        vfs_kern_mount.part.0+0x71/0xb0
[ 3653.730800]        btrfs_mount+0x11d/0x3a0 [btrfs]
[ 3653.731427]        legacy_get_tree+0x30/0x50
[ 3653.731970]        vfs_get_tree+0x28/0xc0
[ 3653.732486]        path_mount+0x2d4/0xbe0
[ 3653.732997]        __x64_sys_mount+0x103/0x140
[ 3653.733560]        do_syscall_64+0x3b/0xc0
[ 3653.734080]        entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.734782]
               other info that might help us debug this:

[ 3653.735784] Chain exists of:
                 &disk->open_mutex --> sb_internal#2 --> btrfs-chunk-00

[ 3653.737123]  Possible unsafe locking scenario:

[ 3653.737865]        CPU0                    CPU1
[ 3653.738435]        ----                    ----
[ 3653.739007]   lock(btrfs-chunk-00);
[ 3653.739449]                                lock(sb_internal#2);
[ 3653.740193]                                lock(btrfs-chunk-00);
[ 3653.740955]   lock(&disk->open_mutex);
[ 3653.741431]
                *** DEADLOCK ***

[ 3653.742176] 3 locks held by mount/447465:
[ 3653.742739]  #0: ffff8c6acf85c0e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xd5/0x3b0
[ 3653.744114]  #1: ffffffffc0b28f70 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x59/0x870 [btrfs]
[ 3653.745563]  #2: ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs]
[ 3653.747066]
               stack backtrace:
[ 3653.747723] CPU: 4 PID: 447465 Comm: mount Not tainted 5.15.0-rc7-btrfs-next-103 #1
[ 3653.748873] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 3653.750592] Call Trace:
[ 3653.750967]  dump_stack_lvl+0x57/0x72
[ 3653.751526]  check_noncircular+0xf3/0x110
[ 3653.752136]  ? stack_trace_save+0x4b/0x70
[ 3653.752748]  __lock_acquire+0x130e/0x2210
[ 3653.753356]  lock_acquire+0xd7/0x310
[ 3653.753898]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.754596]  ? lock_is_held_type+0xe8/0x140
[ 3653.755125]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.755729]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.756338]  __mutex_lock+0x92/0x900
[ 3653.756794]  ? blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.757400]  ? do_raw_spin_unlock+0x4b/0xa0
[ 3653.757930]  ? _raw_spin_unlock+0x29/0x40
[ 3653.758437]  ? bd_prepare_to_claim+0x129/0x150
[ 3653.758999]  ? trace_module_get+0x2b/0xd0
[ 3653.759508]  ? try_module_get.part.0+0x50/0x80
[ 3653.760072]  blkdev_get_by_dev.part.0+0xe7/0x320
[ 3653.760661]  ? devcgroup_check_permission+0xc1/0x1f0
[ 3653.761288]  blkdev_get_by_path+0xb8/0xd0
[ 3653.761797]  btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
[ 3653.762454]  open_fs_devices+0xd7/0x2c0 [btrfs]
[ 3653.763055]  ? clone_fs_devices+0x8f/0x170 [btrfs]
[ 3653.763689]  btrfs_read_chunk_tree+0x3ad/0x870 [btrfs]
[ 3653.764370]  ? kvm_sched_clock_read+0x14/0x40
[ 3653.764922]  open_ctree+0xb8e/0x17bf [btrfs]
[ 3653.765493]  ? super_setup_bdi_name+0x79/0xd0
[ 3653.766043]  btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 3653.766780]  ? rcu_read_lock_sched_held+0x3f/0x80
[ 3653.767488]  ? kfree+0x1f2/0x3c0
[ 3653.767979]  legacy_get_tree+0x30/0x50
[ 3653.768548]  vfs_get_tree+0x28/0xc0
[ 3653.769076]  vfs_kern_mount.part.0+0x71/0xb0
[ 3653.769718]  btrfs_mount+0x11d/0x3a0 [btrfs]
[ 3653.770381]  ? rcu_read_lock_sched_held+0x3f/0x80
[ 3653.771086]  ? kfree+0x1f2/0x3c0
[ 3653.771574]  legacy_get_tree+0x30/0x50
[ 3653.772136]  vfs_get_tree+0x28/0xc0
[ 3653.772673]  path_mount+0x2d4/0xbe0
[ 3653.773201]  __x64_sys_mount+0x103/0x140
[ 3653.773793]  do_syscall_64+0x3b/0xc0
[ 3653.774333]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3653.775094] RIP: 0033:0x7f648bc45aaa

This happens because through btrfs_read_chunk_tree(), which is called only
during mount, ends up acquiring the mutex open_mutex of a block device
while holding a read lock on a leaf of the chunk tree while other paths
need to acquire other locks before locking extent buffers of the chunk
tree.

Since at mount time when we call btrfs_read_chunk_tree() we know that
we don't have other tasks running in parallel and modifying the chunk
tree, we can simply skip locking of chunk tree extent buffers. So do
that and move the assertion that checks the fs is not yet mounted to the
top block of btrfs_read_chunk_tree(), with a comment before doing it.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08 09:04:39 +01:00