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commit a6862e6708c15995bc10614b2ef34ca35b4b9078 upstream.
Turn some comments into lockdep asserts.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 52dfd86aa568e433b24357bb5fc725560f1e22d8 upstream.
Opening a new file is done in 2 steps on regular filesystems:
1. Call the create inode-op on the parent-dir to create an inode
to hold the meta-data related to the file.
2. Call the open file-op to get a handle for the file.
vboxsf however does not really use disk-backed inodes because it
is based on passing through file-related system-calls through to
the hypervisor. So both steps translate to an open(2) call being
passed through to the hypervisor. With the handle returned by
the first call immediately being closed again.
Making 2 open calls for a single open(..., O_CREATE, ...) calls
has 2 problems:
a) It is not really efficient.
b) It actually breaks some apps.
An example of b) is doing a git clone inside a vboxsf mount.
When git clone tries to create a tempfile to store the pak
files which is downloading the following happens:
1. vboxsf_dir_mkfile() gets called with a mode of 0444 and succeeds.
2. vboxsf_file_open() gets called with file->f_flags containing
O_RDWR. When the host is a Linux machine this fails because doing
a open(..., O_RDWR) on a file which exists and has mode 0444 results
in an -EPERM error.
Other network-filesystems and fuse avoid the problem of needing to
pass 2 open() calls to the other side by using the atomic_open
directory-inode op.
This commit fixes git clone not working inside a vboxsf mount,
by adding support for the atomic_open directory-inode op.
As an added bonus this should also make opening new files faster.
The atomic_open implementation is modelled after the atomic_open
implementations from the 9p and fuse code.
Fixes: 0fd169576648 ("fs: Add VirtualBox guest shared folder (vboxsf) support")
Reported-by: Ludovic Pouzenc <bugreports@pouzenc.fr>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 02f840f90764f22f5c898901849bdbf0cee752ba upstream.
Factor out the code to create / release a struct vboxsf_handle into
2 new helper functions.
This is a preparation patch for adding atomic_open support.
Fixes: 0fd169576648 ("fs: Add VirtualBox guest shared folder (vboxsf) support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bf2ba432213fade50dd39f2e348085b758c0726e upstream.
Function ceph_check_delayed_caps() is called from the mdsc->delayed_work
workqueue and it can be kept looping for quite some time if caps keep
being added back to the mdsc->cap_delay_list. This may result in the
watchdog tainting the kernel with the softlockup flag.
This patch breaks this loop if the caps have been recently (i.e. during
the loop execution). Any new caps added to the list will be handled in
the next run.
Also, allow schedule_delayed() callers to explicitly set the delay value
instead of defaulting to 5s, so we can ensure that it runs soon
afterward if it looks like there is more work.
Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/46284
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7d3fc01796fc895e5fcce45c994c5a8db8120a8d upstream.
We used to follow the rule earlier that the create SD context
always be a multiple of 8. However, with the change:
cifs: refactor create_sd_buf() and and avoid corrupting the buffer
...we recompute the length, and we failed that rule.
Fixing that with this change.
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 427215d85e8d1476da1a86b8d67aceb485eb3631 upstream.
Add the following checks from __do_loopback() to clone_private_mount() as
well:
- verify that the mount is in the current namespace
- verify that there are no locked children
Reported-by: Alois Wohlschlager <alois1@gmx-topmail.de>
Fixes: c771d683a62e ("vfs: introduce clone_private_mount()")
Cc: <stable@vger.kernel.org> # v3.18
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ab0c29687bc7a890d1a86ac376b0b0fd78b2d9b6 upstream
Make vboxsf_dir_create() optionally return the vboxsf-handle for
the created file. This is a preparation patch for adding atomic_open
support.
Fixes: 0fd169576648 ("fs: Add VirtualBox guest shared folder (vboxsf) support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit cc3ddee97cff034cea4d095de4a484c92a219bf5 upstream
Honor the excl flag to the dir-inode create op, instead of behaving
as if it is always set.
Note the old behavior still worked most of the time since a non-exclusive
open only calls the create op, if there is a race and the file is created
between the dentry lookup and the calling of the create call.
While at it change the type of the is_dir parameter to the
vboxsf_dir_create() helper from an int to a bool, to be consistent with
the use of bool for the excl parameter.
Fixes: 0fd169576648 ("fs: Add VirtualBox guest shared folder (vboxsf) support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 5ad4df56cd2158965f73416d41fce37906724822 ]
Clang detected a problem with rc possibly being unitialized
(when length is zero) in a recently added fallocate code path.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 13d257503c0930010ef9eed78b689cec417ab741 ]
While verifying the leaf item that we read from the disk, reiserfs
doesn't check the directory items, this could cause a crash when we
read a directory item from the disk that has an invalid deh_location.
This patch adds a check to the directory items read from the disk that
does a bounds check on deh_location for the directory entries. Any
directory entry header with a directory entry offset greater than the
item length is considered invalid.
Link: https://lore.kernel.org/r/20210709152929.766363-1-chouhan.shreyansh630@gmail.com
Reported-by: syzbot+c31a48e6702ccb3d64c9@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2acf15b94d5b8ea8392c4b6753a6ffac3135cd78 ]
Our syzcaller report a NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 116e95067 P4D 116e95067 PUD 1080b5067 PMD 0
Oops: 0010 [#1] SMP KASAN
CPU: 7 PID: 592 Comm: a.out Not tainted 5.13.0-next-20210629-dirty #67
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-p4
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffff888114e779b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff110229cef39 RCX: ffffffffaa67e1aa
RDX: 0000000000000000 RSI: ffff88810a58ee00 RDI: ffff8881233180b0
RBP: ffffffffac38e9c0 R08: ffffffffaa67e17e R09: 0000000000000001
R10: ffffffffb91c5557 R11: fffffbfff7238aaa R12: ffff88810a58ee00
R13: ffff888114e77aa0 R14: 0000000000000000 R15: ffff8881233180b0
FS: 00007f946163c480(0000) GS:ffff88839f1c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001099c1000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__lookup_slow+0x116/0x2d0
? page_put_link+0x120/0x120
? __d_lookup+0xfc/0x320
? d_lookup+0x49/0x90
lookup_one_len+0x13c/0x170
? __lookup_slow+0x2d0/0x2d0
? reiserfs_schedule_old_flush+0x31/0x130
reiserfs_lookup_privroot+0x64/0x150
reiserfs_fill_super+0x158c/0x1b90
? finish_unfinished+0xb10/0xb10
? bprintf+0xe0/0xe0
? __mutex_lock_slowpath+0x30/0x30
? __kasan_check_write+0x20/0x30
? up_write+0x51/0xb0
? set_blocksize+0x9f/0x1f0
mount_bdev+0x27c/0x2d0
? finish_unfinished+0xb10/0xb10
? reiserfs_kill_sb+0x120/0x120
get_super_block+0x19/0x30
legacy_get_tree+0x76/0xf0
vfs_get_tree+0x49/0x160
? capable+0x1d/0x30
path_mount+0xacc/0x1380
? putname+0x97/0xd0
? finish_automount+0x450/0x450
? kmem_cache_free+0xf8/0x5a0
? putname+0x97/0xd0
do_mount+0xe2/0x110
? path_mount+0x1380/0x1380
? copy_mount_options+0x69/0x140
__x64_sys_mount+0xf0/0x190
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
This is because 'root_inode' is initialized with wrong mode, and
it's i_op is set to 'reiserfs_special_inode_operations'. Thus add
check for 'root_inode' to fix the problem.
Link: https://lore.kernel.org/r/20210702040743.1918552-1-yukuai3@huawei.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 877ba3f729fd3d8ef0e29bc2a55e57cfa54b2e43 upstream.
Commit b5776e7524af ("ext4: fix potential htree index checksum
corruption) removed a required restart when multiple levels of index
nodes need to be split. Fix this to avoid directory htree corruptions
when using the large_dir feature.
Cc: stable@kernel.org # v5.11
Cc: Благодаренко Артём <artem.blagodarenko@gmail.com>
Fixes: b5776e7524af ("ext4: fix potential htree index checksum corruption)
Reported-by: Denis <denis@voxelsoft.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 46c4c9d1beb7f5b4cec4dd90e7728720583ee348 upstream.
This program always prints 4096 and hangs before the patch, and always
prints 8192 and exits successfully after:
int main()
{
int pipefd[2];
for (int i = 0; i < 1025; i++)
if (pipe(pipefd) == -1)
return 1;
size_t bufsz = fcntl(pipefd[1], F_GETPIPE_SZ);
printf("%zd\n", bufsz);
char *buf = calloc(bufsz, 1);
write(pipefd[1], buf, bufsz);
read(pipefd[0], buf, bufsz-1);
write(pipefd[1], buf, 1);
}
Note that you may need to increase your RLIMIT_NOFILE before running the
program.
Fixes: 759c01142a ("pipe: limit the per-user amount of pages allocated in pipes")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/lkml/1628086770.5rn8p04n6j.none@localhost/
Link: https://lore.kernel.org/lkml/1628127094.lxxn016tj7.none@localhost/
Signed-off-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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eviction
[ Upstream commit ecc64fab7d49c678e70bd4c35fe64d2ab3e3d212 ]
When checking if we need to log the new name of a renamed inode, we are
checking if the inode and its parent inode have been logged before, and if
not we don't log the new name. The check however is buggy, as it directly
compares the logged_trans field of the inodes versus the ID of the current
transaction. The problem is that logged_trans is a transient field, only
stored in memory and never persisted in the inode item, so if an inode
was logged before, evicted and reloaded, its logged_trans field is set to
a value of 0, meaning the check will return false and the new name of the
renamed inode is not logged. If the old parent directory was previously
fsynced and we deleted the logged directory entries corresponding to the
old name, we end up with a log that when replayed will delete the renamed
inode.
The following example triggers the problem:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/A
$ mkdir /mnt/B
$ echo -n "hello world" > /mnt/A/foo
$ sync
# Add some new file to A and fsync directory A.
$ touch /mnt/A/bar
$ xfs_io -c "fsync" /mnt/A
# Now trigger inode eviction. We are only interested in triggering
# eviction for the inode of directory A.
$ echo 2 > /proc/sys/vm/drop_caches
# Move foo from directory A to directory B.
# This deletes the directory entries for foo in A from the log, and
# does not add the new name for foo in directory B to the log, because
# logged_trans of A is 0, which is less than the current transaction ID.
$ mv /mnt/A/foo /mnt/B/foo
# Now make an fsync to anything except A, B or any file inside them,
# like for example create a file at the root directory and fsync this
# new file. This syncs the log that contains all the changes done by
# previous rename operation.
$ touch /mnt/baz
$ xfs_io -c "fsync" /mnt/baz
<power fail>
# Mount the filesystem and replay the log.
$ mount /dev/sdc /mnt
# Check the filesystem content.
$ ls -1R /mnt
/mnt/:
A
B
baz
/mnt/A:
bar
/mnt/B:
$
# File foo is gone, it's neither in A/ nor in B/.
Fix this by using the inode_logged() helper at btrfs_log_new_name(), which
safely checks if an inode was logged before in the current transaction.
A test case for fstests will follow soon.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit de53d892e5c51dfa0a158e812575a75a6c991f39 ]
When we are doing a rename or a link operation for an inode that was logged
in the previous transaction and that transaction is still committing, we
have a time window where we incorrectly consider that the inode was logged
previously in the current transaction and therefore decide to log it to
update it in the log. The following steps give an example on how this
happens during a link operation:
1) Inode X is logged in transaction 1000, so its logged_trans field is set
to 1000;
2) Task A starts to commit transaction 1000;
3) The state of transaction 1000 is changed to TRANS_STATE_UNBLOCKED;
4) Task B starts a link operation for inode X, and as a consequence it
starts transaction 1001;
5) Task A is still committing transaction 1000, therefore the value stored
at fs_info->last_trans_committed is still 999;
6) Task B calls btrfs_log_new_name(), it reads a value of 999 from
fs_info->last_trans_committed and because the logged_trans field of
inode X has a value of 1000, the function does not return immediately,
instead it proceeds to logging the inode, which should not happen
because the inode was logged in the previous transaction (1000) and
not in the current one (1001).
This is not a functional problem, just wasted time and space logging an
inode that does not need to be logged, contributing to higher latency
for link and rename operations.
So fix this by comparing the inodes' logged_trans field with the
generation of the current transaction instead of comparing with the value
stored in fs_info->last_trans_committed.
This case is often hit when running dbench for a long enough duration, as
it does lots of rename operations.
This patch belongs to a patch set that is comprised of the following
patches:
btrfs: fix race causing unnecessary inode logging during link and rename
btrfs: fix race that results in logging old extents during a fast fsync
btrfs: fix race that causes unnecessary logging of ancestor inodes
btrfs: fix race that makes inode logging fallback to transaction commit
btrfs: fix race leading to unnecessary transaction commit when logging inode
btrfs: do not block inode logging for so long during transaction commit
Performance results are mentioned in the change log of the last patch.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit f2a26a3cff27dfa456fef386fe5df56dcb4b47b6 upstream.
readpage was calculating the offset of the page incorrectly
for the case of large swapcaches.
loff_t offset = (loff_t)page->index << PAGE_SHIFT;
As pointed out by Matthew Wilcox, this needs to use
page_file_offset() to calculate the offset instead.
Pages coming from the swap cache have page->index set
to their index within the swapcache, not within the backing
file. For a sufficiently large swapcache, we could have
overlapping values of page->index within the same backing file.
Suggested by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9449ad33be8480f538b11a593e2dda2fb33ca06d upstream.
For punch holes in EOF blocks, fallocate used buffer write to zero the
EOF blocks in last cluster. But since ->writepage will ignore EOF
pages, those zeros will not be flushed.
This "looks" ok as commit 6bba4471f0cc ("ocfs2: fix data corruption by
fallocate") will zero the EOF blocks when extend the file size, but it
isn't. The problem happened on those EOF pages, before writeback, those
pages had DIRTY flag set and all buffer_head in them also had DIRTY flag
set, when writeback run by write_cache_pages(), DIRTY flag on the page
was cleared, but DIRTY flag on the buffer_head not.
When next write happened to those EOF pages, since buffer_head already
had DIRTY flag set, it would not mark page DIRTY again. That made
writeback ignore them forever. That will cause data corruption. Even
directio write can't work because it will fail when trying to drop pages
caches before direct io, as it found the buffer_head for those pages
still had DIRTY flag set, then it will fall back to buffer io mode.
To make a summary of the issue, as writeback ingores EOF pages, once any
EOF page is generated, any write to it will only go to the page cache,
it will never be flushed to disk even file size extends and that page is
not EOF page any more. The fix is to avoid zero EOF blocks with buffer
write.
The following code snippet from qemu-img could trigger the corruption.
656 open("6b3711ae-3306-4bdd-823c-cf1c0060a095.conv.2", O_RDWR|O_DIRECT|O_CLOEXEC) = 11
...
660 fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2275868672, 327680 <unfinished ...>
660 fallocate(11, 0, 2275868672, 327680) = 0
658 pwrite64(11, "
Link: https://lkml.kernel.org/r/20210722054923.24389-2-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f267aeb6dea5e468793e5b8eb6a9c72c0020d418 upstream.
If append-dio feature is enabled, direct-io write and fallocate could
run in parallel to extend file size, fallocate used "orig_isize" to
record i_size before taking "ip_alloc_sem", when
ocfs2_zeroout_partial_cluster() zeroout EOF blocks, i_size maybe already
extended by ocfs2_dio_end_io_write(), that will cause valid data zeroed
out.
Link: https://lkml.kernel.org/r/20210722054923.24389-1-junxiao.bi@oracle.com
Fixes: 6bba4471f0cc ("ocfs2: fix data corruption by fallocate")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 240246f6b913b0c23733cfd2def1d283f8cc9bbe upstream.
In compression write endio sequence, the range which the compressed_bio
writes is marked as uptodate if the last bio of the compressed (sub)bios
is completed successfully. There could be previous bio which may
have failed which is recorded in cb->errors.
Set the writeback range as uptodate only if cb->errors is zero, as opposed
to checking only the last bio's status.
Backporting notes: in all versions up to 4.4 the last argument is always
replaced by "!cb->errors".
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@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>
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commit b2a616676839e2a6b02c8e40be7f886f882ed194 upstream.
When removing a writeable device in __btrfs_free_extra_devids, the rw
device count should be decremented.
This error was caught by Syzbot which reported a warning in
close_fs_devices:
WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
Modules linked in:
CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293
RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128
R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a
FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180
open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693
btrfs_fill_super fs/btrfs/super.c:1382 [inline]
btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
fc_mount fs/namespace.c:993 [inline]
vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023
btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x196f/0x2be0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
Because fs_devices->rw_devices was not 0 after
closing all devices. Here is the call trace that was observed:
btrfs_mount_root():
btrfs_scan_one_device():
device_list_add(); <---------------- device added
btrfs_open_devices():
open_fs_devices():
btrfs_open_one_device(); <-------- writable device opened,
rw device count ++
btrfs_fill_super():
open_ctree():
btrfs_free_extra_devids():
__btrfs_free_extra_devids(); <--- writable device removed,
rw device count not decremented
fail_tree_roots:
btrfs_close_devices():
close_fs_devices(); <------- rw device count off by 1
As a note, prior to commit cf89af146b7e ("btrfs: dev-replace: fail
mount if we don't have replace item with target device"), rw_devices
was decremented on removing a writable device in
__btrfs_free_extra_devids only if the BTRFS_DEV_STATE_REPLACE_TGT bit
was not set for the device. However, this check does not need to be
reinstated as it is now redundant and incorrect.
In __btrfs_free_extra_devids, we skip removing the device if it is the
target for replacement. This is done by checking whether device->devid
== BTRFS_DEV_REPLACE_DEVID. Since BTRFS_DEV_STATE_REPLACE_TGT is set
only on the device with devid BTRFS_DEV_REPLACE_DEVID, no devices
should have the BTRFS_DEV_STATE_REPLACE_TGT bit set after the check,
and so it's redundant to test for that bit.
Additionally, following commit 82372bc816d7 ("Btrfs: make
the logic of source device removing more clear"), rw_devices is
incremented whenever a writeable device is added to the alloc
list (including the target device in btrfs_dev_replace_finishing), so
all removals of writable devices from the alloc list should also be
accompanied by a decrement to rw_devices.
Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Fixes: cf89af146b7e ("btrfs: dev-replace: fail mount if we don't have replace item with target device")
CC: stable@vger.kernel.org # 5.10+
Tested-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 3a34b13a88caeb2800ab44a4918f230041b37dd9 upstream.
Since commit 1b6b26ae7053 ("pipe: fix and clarify pipe write wakeup
logic") we have sanitized the pipe write logic, and would only try to
wake up readers if they needed it.
In particular, if the pipe already had data in it before the write,
there was no point in trying to wake up a reader, since any existing
readers must have been aware of the pre-existing data already. Doing
extraneous wakeups will only cause potential thundering herd problems.
However, it turns out that some Android libraries have misused the EPOLL
interface, and expected "edge triggered" be to "any new write will
trigger it". Even if there was no edge in sight.
Quoting Sandeep Patil:
"The commit 1b6b26ae7053 ('pipe: fix and clarify pipe write wakeup
logic') changed pipe write logic to wakeup readers only if the pipe
was empty at the time of write. However, there are libraries that
relied upon the older behavior for notification scheme similar to
what's described in [1]
One such library 'realm-core'[2] is used by numerous Android
applications. The library uses a similar notification mechanism as GNU
Make but it never drains the pipe until it is full. When Android moved
to v5.10 kernel, all applications using this library stopped working.
The library has since been fixed[3] but it will be a while before all
applications incorporate the updated library"
Our regression rule for the kernel is that if applications break from
new behavior, it's a regression, even if it was because the application
did something patently wrong. Also note the original report [4] by
Michal Kerrisk about a test for this epoll behavior - but at that point
we didn't know of any actual broken use case.
So add the extraneous wakeup, to approximate the old behavior.
[ I say "approximate", because the exact old behavior was to do a wakeup
not for each write(), but for each pipe buffer chunk that was filled
in. The behavior introduced by this change is not that - this is just
"every write will cause a wakeup, whether necessary or not", which
seems to be sufficient for the broken library use. ]
It's worth noting that this adds the extraneous wakeup only for the
write side, while the read side still considers the "edge" to be purely
about reading enough from the pipe to allow further writes.
See commit f467a6a66419 ("pipe: fix and clarify pipe read wakeup logic")
for the pipe read case, which remains that "only wake up if the pipe was
full, and we read something from it".
Link: https://lore.kernel.org/lkml/CAHk-=wjeG0q1vgzu4iJhW5juPkTsjTYmiqiMUYAebWW+0bam6w@mail.gmail.com/ [1]
Link: https://github.com/realm/realm-core [2]
Link: https://github.com/realm/realm-core/issues/4666 [3]
Link: https://lore.kernel.org/lkml/CAKgNAkjMBGeAwF=2MKK758BhxvW58wYTgYKB2V-gY1PwXxrH+Q@mail.gmail.com/ [4]
Link: https://lore.kernel.org/lkml/20210729222635.2937453-1-sspatil@android.com/
Reported-by: Sandeep Patil <sspatil@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
I met a null-ptr-deref when doing fault-inject test:
[ 65.441626][ T8299] general protection fault, probably for non-canonical address 0xdffffc0000000029: 0000 [#1] PREEMPT SMP KASAN
[ 65.443219][ T8299] KASAN: null-ptr-deref in range [0x0000000000000148-0x000000000000014f]
[ 65.444331][ T8299] CPU: 2 PID: 8299 Comm: test Not tainted 5.10.49+ #499
[ 65.445277][ T8299] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[ 65.446614][ T8299] RIP: 0010:io_disable_sqo_submit+0x124/0x260
[ 65.447554][ T8299] Code: 7b 40 89 ee e8 2d b9 9a ff 85 ed 74 40 e8 04 b8 9a ff 49 8d be 48 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 22 01 00 00 49 8b ae 48 01 00 00 48 85 ed 74 0d
[ 65.450860][ T8299] RSP: 0018:ffffc9000122fd70 EFLAGS: 00010202
[ 65.451826][ T8299] RAX: dffffc0000000000 RBX: ffff88801b11f000 RCX: ffffffff81d5d783
[ 65.453166][ T8299] RDX: 0000000000000029 RSI: ffffffff81d5d78c RDI: 0000000000000148
[ 65.454606][ T8299] RBP: 0000000000000002 R08: ffff88810168c280 R09: ffffed1003623e79
[ 65.456063][ T8299] R10: ffffc9000122fd70 R11: ffffed1003623e78 R12: ffff88801b11f040
[ 65.457542][ T8299] R13: ffff88801b11f3c0 R14: 0000000000000000 R15: 000000000000001a
[ 65.458910][ T8299] FS: 00007ffb602e3500(0000) GS:ffff888064100000(0000) knlGS:0000000000000000
[ 65.460533][ T8299] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 65.461736][ T8299] CR2: 00007ffb5fe7eb24 CR3: 000000010a619000 CR4: 0000000000750ee0
[ 65.463146][ T8299] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 65.464618][ T8299] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 65.466052][ T8299] PKRU: 55555554
[ 65.466708][ T8299] Call Trace:
[ 65.467304][ T8299] io_uring_setup+0x2041/0x3ac0
[ 65.468169][ T8299] ? io_iopoll_check+0x500/0x500
[ 65.469123][ T8299] ? syscall_enter_from_user_mode+0x1c/0x50
[ 65.470241][ T8299] do_syscall_64+0x2d/0x70
[ 65.471028][ T8299] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 65.472099][ T8299] RIP: 0033:0x7ffb5fdec839
[ 65.472925][ T8299] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
[ 65.476465][ T8299] RSP: 002b:00007ffc33539ef8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9
[ 65.478026][ T8299] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffb5fdec839
[ 65.479503][ T8299] RDX: 0000000020ffd000 RSI: 0000000020000080 RDI: 0000000000100001
[ 65.480927][ T8299] RBP: 00007ffc33539f70 R08: 0000000000000000 R09: 0000000000000000
[ 65.482416][ T8299] R10: 0000000000000000 R11: 0000000000000206 R12: 0000555e85531320
[ 65.483845][ T8299] R13: 00007ffc3353a0a0 R14: 0000000000000000 R15: 0000000000000000
[ 65.485331][ T8299] Modules linked in:
[ 65.486000][ T8299] Dumping ftrace buffer:
[ 65.486772][ T8299] (ftrace buffer empty)
[ 65.487595][ T8299] ---[ end trace a9a5fad3ebb303b7 ]---
If io_allocate_scq_urings() fails in io_uring_create(), 'ctx->sq_data'
is not set yet, when calling io_sq_offload_start() in io_disable_sqo_submit()
in error path, it will lead a null-ptr-deref.
The io_disable_sqo_submit() has been removed in mainline by commit
70aacfe66136 ("io_uring: kill sqo_dead and sqo submission halting"),
so the bug has been eliminated in mainline, it's a fix only for stable-5.10.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 49694d14ff68fa4b5f86019dbcfb44a8bd213e58 ]
The length variable is rather pointless given that it can be trivially
deduced from offset and size. Also the initial calculation can lead
to KASAN warnings.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Leizhen (ThunderTown) <thunder.leizhen@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 3ac1d426510f97ace05093ae9f2f710d9cbe6215 ]
The length variable is rather pointless given that it can be trivially
deduced from offset and size. Also the initial calculation can lead
to KASAN warnings.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Leizhen (ThunderTown) <thunder.leizhen@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit c9c9c6815f9004ee1ec87401ed0796853bd70f1b ]
Because the out of range assignment to bit fields
are compiler-dependant, the fields could have wrong
value.
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit b3b2177a2d795e35dc11597b2609eb1e7e57e570 ]
Syzbot reports a possible recursive lock in [1].
This happens due to missing lock nesting information. From the logs, we
see that a call to hfs_fill_super is made to mount the hfs filesystem.
While searching for the root inode, the lock on the catalog btree is
grabbed. Then, when the parent of the root isn't found, a call to
__hfs_bnode_create is made to create the parent of the root. This
eventually leads to a call to hfs_ext_read_extent which grabs a lock on
the extents btree.
Since the order of locking is catalog btree -> extents btree, this lock
hierarchy does not lead to a deadlock.
To tell lockdep that this locking is safe, we add nesting notation to
distinguish between catalog btrees, extents btrees, and attributes
btrees (for HFS+). This has already been done in hfsplus.
Link: https://syzkaller.appspot.com/bug?id=f007ef1d7a31a469e3be7aeb0fde0769b18585db [1]
Link: https://lkml.kernel.org/r/20210701030756.58760-4-desmondcheongzx@gmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reported-by: syzbot+b718ec84a87b7e73ade4@syzkaller.appspotmail.com
Tested-by: syzbot+b718ec84a87b7e73ade4@syzkaller.appspotmail.com
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 54a5ead6f5e2b47131a7385d0c0af18e7b89cb02 ]
Pages that we read in hfs_bnode_read need to be kmapped into kernel
address space. However, currently only the 0th page is kmapped. If the
given offset + length exceeds this 0th page, then we have an invalid
memory access.
To fix this, we kmap relevant pages one by one and copy their relevant
portions of data.
An example of invalid memory access occurring without this fix can be seen
in the following crash report:
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: use-after-free in hfs_bnode_read+0xc4/0xe0 fs/hfs/bnode.c:26
Read of size 2 at addr ffff888125fdcffe by task syz-executor5/4634
CPU: 0 PID: 4634 Comm: syz-executor5 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x195/0x1f8 lib/dump_stack.c:120
print_address_description.constprop.0+0x1d/0x110 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x7b/0xd4 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:180 [inline]
kasan_check_range+0x154/0x1b0 mm/kasan/generic.c:186
memcpy+0x24/0x60 mm/kasan/shadow.c:65
memcpy include/linux/fortify-string.h:191 [inline]
hfs_bnode_read+0xc4/0xe0 fs/hfs/bnode.c:26
hfs_bnode_read_u16 fs/hfs/bnode.c:34 [inline]
hfs_bnode_find+0x880/0xcc0 fs/hfs/bnode.c:365
hfs_brec_find+0x2d8/0x540 fs/hfs/bfind.c:126
hfs_brec_read+0x27/0x120 fs/hfs/bfind.c:165
hfs_cat_find_brec+0x19a/0x3b0 fs/hfs/catalog.c:194
hfs_fill_super+0xc13/0x1460 fs/hfs/super.c:419
mount_bdev+0x331/0x3f0 fs/super.c:1368
hfs_mount+0x35/0x40 fs/hfs/super.c:457
legacy_get_tree+0x10c/0x220 fs/fs_context.c:592
vfs_get_tree+0x93/0x300 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x13f5/0x20e0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount fs/namespace.c:3433 [inline]
__x64_sys_mount+0x2b8/0x340 fs/namespace.c:3433
do_syscall_64+0x37/0xc0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x45e63a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 88 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9404d410d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000248 RCX: 000000000045e63a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f9404d41120
RBP: 00007f9404d41120 R08: 00000000200002c0 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000003 R14: 00000000004ad5d8 R15: 0000000000000000
The buggy address belongs to the page:
page:00000000dadbcf3e refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x125fdc
flags: 0x2fffc0000000000(node=0|zone=2|lastcpupid=0x3fff)
raw: 02fffc0000000000 ffffea000497f748 ffffea000497f6c8 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888125fdce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888125fdcf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888125fdcf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888125fdd000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888125fdd080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
Link: https://lkml.kernel.org/r/20210701030756.58760-3-desmondcheongzx@gmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 16ee572eaf0d09daa4c8a755fdb71e40dbf8562d ]
Patch series "hfs: fix various errors", v2.
This series ultimately aims to address a lockdep warning in
hfs_find_init reported by Syzbot [1].
The work done for this led to the discovery of another bug, and the
Syzkaller repro test also reveals an invalid memory access error after
clearing the lockdep warning. Hence, this series is broken up into
three patches:
1. Add a missing call to hfs_find_exit for an error path in
hfs_fill_super
2. Fix memory mapping in hfs_bnode_read by fixing calls to kmap
3. Add lock nesting notation to tell lockdep that the observed locking
hierarchy is safe
This patch (of 3):
Before exiting hfs_fill_super, the struct hfs_find_data used in
hfs_find_init should be passed to hfs_find_exit to be cleaned up, and to
release the lock held on the btree.
The call to hfs_find_exit is missing from an error path. We add it back
in by consolidating calls to hfs_find_exit for error paths.
Link: https://syzkaller.appspot.com/bug?id=f007ef1d7a31a469e3be7aeb0fde0769b18585db [1]
Link: https://lkml.kernel.org/r/20210701030756.58760-1-desmondcheongzx@gmail.com
Link: https://lkml.kernel.org/r/20210701030756.58760-2-desmondcheongzx@gmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 1e7107c5ef44431bc1ebbd4c353f1d7c22e5f2ec upstream.
Richard reported sporadic (roughly one in 10 or so) null dereferences and
other strange behaviour for a set of automated LTP tests. Things like:
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 1516 Comm: umount Not tainted 5.10.0-yocto-standard #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
RIP: 0010:kernfs_sop_show_path+0x1b/0x60
...or these others:
RIP: 0010:do_mkdirat+0x6a/0xf0
RIP: 0010:d_alloc_parallel+0x98/0x510
RIP: 0010:do_readlinkat+0x86/0x120
There were other less common instances of some kind of a general scribble
but the common theme was mount and cgroup and a dubious dentry triggering
the NULL dereference. I was only able to reproduce it under qemu by
replicating Richard's setup as closely as possible - I never did get it
to happen on bare metal, even while keeping everything else the same.
In commit 71d883c37e8d ("cgroup_do_mount(): massage calling conventions")
we see this as a part of the overall change:
--------------
struct cgroup_subsys *ss;
- struct dentry *dentry;
[...]
- dentry = cgroup_do_mount(&cgroup_fs_type, fc->sb_flags, root,
- CGROUP_SUPER_MAGIC, ns);
[...]
- if (percpu_ref_is_dying(&root->cgrp.self.refcnt)) {
- struct super_block *sb = dentry->d_sb;
- dput(dentry);
+ ret = cgroup_do_mount(fc, CGROUP_SUPER_MAGIC, ns);
+ if (!ret && percpu_ref_is_dying(&root->cgrp.self.refcnt)) {
+ struct super_block *sb = fc->root->d_sb;
+ dput(fc->root);
deactivate_locked_super(sb);
msleep(10);
return restart_syscall();
}
--------------
In changing from the local "*dentry" variable to using fc->root, we now
export/leave that dentry pointer in the file context after doing the dput()
in the unlikely "is_dying" case. With LTP doing a crazy amount of back to
back mount/unmount [testcases/bin/cgroup_regression_5_1.sh] the unlikely
becomes slightly likely and then bad things happen.
A fix would be to not leave the stale reference in fc->root as follows:
--------------
dput(fc->root);
+ fc->root = NULL;
deactivate_locked_super(sb);
--------------
...but then we are just open-coding a duplicate of fc_drop_locked() so we
simply use that instead.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Fixes: 71d883c37e8d ("cgroup_do_mount(): massage calling conventions")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 ]
WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28
RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
io_put_req fs/io_uring.c:2140 [inline]
io_queue_linked_timeout fs/io_uring.c:6300 [inline]
__io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354
io_submit_sqe fs/io_uring.c:6534 [inline]
io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660
__do_sys_io_uring_enter fs/io_uring.c:9240 [inline]
__se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182
io_link_timeout_fn() should put only one reference of the linked timeout
request, however in case of racing with the master request's completion
first io_req_complete() puts one and then io_put_req_deferred() is
called.
Cc: stable@vger.kernel.org # 5.12+
Fixes: 9ae1f8dd372e0 ("io_uring: fix inconsistent lock state")
Reported-by: syzbot+a2910119328ce8e7996f@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ff51018ff29de5ffa76f09273ef48cb24c720368.1620417627.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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