linux-stable.git/fs, branch v4.4.211

ocfs2: call journal flush to mark journal as empty after journal recovery when mount

2020-01-23T07:18:38+00:00

[ Upstream commit 397eac17f86f404f5ba31d8c3e39ec3124b39fd3 ]

If journal is dirty when mount, it will be replayed but jbd2 sb log tail
cannot be updated to mark a new start because journal->j_flag has
already been set with JBD2_ABORT first in journal_init_common.

When a new transaction is committed, it will be recored in block 1
first(journal->j_tail is set to 1 in journal_reset).  If emergency
restart happens again before journal super block is updated
unfortunately, the new recorded trans will not be replayed in the next
mount.

The following steps describe this procedure in detail.
1. mount and touch some files
2. these transactions are committed to journal area but not checkpointed
3. emergency restart
4. mount again and its journals are replayed
5. journal super block's first s_start is 1, but its s_seq is not updated
6. touch a new file and its trans is committed but not checkpointed
7. emergency restart again
8. mount and journal is dirty, but trans committed in 6 will not be
replayed.

This exception happens easily when this lun is used by only one node.
If it is used by multi-nodes, other node will replay its journal and its
journal super block will be updated after recovery like what this patch
does.

ocfs2_recover_node->ocfs2_replay_journal.

The following jbd2 journal can be generated by touching a new file after
journal is replayed, and seq 15 is the first valid commit, but first seq
is 13 in journal super block.

logdump:
  Block 0: Journal Superblock
  Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
  Blocksize: 4096   Total Blocks: 32768   First Block: 1
  First Commit ID: 13   Start Log Blknum: 1
  Error: 0
  Feature Compat: 0
  Feature Incompat: 2 block64
  Feature RO compat: 0
  Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
  FS Share Cnt: 1   Dynamic Superblk Blknum: 0
  Per Txn Block Limit    Journal: 0    Data: 0

  Block 1: Journal Commit Block
  Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)

  Block 2: Journal Descriptor
  Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
  No. Blocknum        Flags
   0. 587             none
  UUID: 00000000000000000000000000000000
   1. 8257792         JBD2_FLAG_SAME_UUID
   2. 619             JBD2_FLAG_SAME_UUID
   3. 24772864        JBD2_FLAG_SAME_UUID
   4. 8257802         JBD2_FLAG_SAME_UUID
   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
  ...
  Block 7: Inode
  Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
  FS Generation: 2839773110 (0xa9437fb6)
  CRC32: 00000000   ECC: 0000
  Type: Regular   Attr: 0x0   Flags: Valid
  Dynamic Features: (0x1) InlineData
  User: 0 (root)   Group: 0 (root)   Size: 7
  Links: 1   Clusters: 0
  ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
  atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
  mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
  dtime: 0x0 -- Thu Jan  1 08:00:00 1970
  ...
  Block 9: Journal Commit Block
  Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)

The following is journal recovery log when recovering the upper jbd2
journal when mount again.

syslog:
  ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
  fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
  fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
  fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
  fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13

Due to first commit seq 13 recorded in journal super is not consistent
with the value recorded in block 1(seq is 14), journal recovery will be
terminated before seq 15 even though it is an unbroken commit, inode
8257802 is a new file and it will be lost.

Link: http://lkml.kernel.org/r/20191217020140.2197-1-li.kai4@h3c.com
Signed-off-by: Kai Li 
Reviewed-by: Joseph Qi 
Reviewed-by: Changwei Ge 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Gang He 
Cc: Jun Piao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

cifs: Adjust indentation in smb2_open_file

2020-01-23T07:18:36+00:00

commit 7935799e041ae10d380d04ea23868240f082bd11 upstream.

Clang warns:

../fs/cifs/smb2file.c:70:3: warning: misleading indentation; statement
is not part of the previous 'if' [-Wmisleading-indentation]
         if (oparms->tcon->use_resilient) {
         ^
../fs/cifs/smb2file.c:66:2: note: previous statement is here
        if (rc)
        ^
1 warning generated.

This warning occurs because there is a space after the tab on this line.
Remove it so that the indentation is consistent with the Linux kernel
coding style and clang no longer warns.

Fixes: 592fafe644bf ("Add resilienthandles mount parm")
Link: https://github.com/ClangBuiltLinux/linux/issues/826
Signed-off-by: Nathan Chancellor 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

ext4: add more paranoia checking in ext4_expand_extra_isize handling

2020-01-23T07:18:36+00:00

commit 4ea99936a1630f51fc3a2d61a58ec4a1c4b7d55a upstream.

It's possible to specify a non-zero s_want_extra_isize via debugging
option, and this can cause bad things(tm) to happen when using a file
system with an inode size of 128 bytes.

Add better checking when the file system is mounted, as well as when
we are actually doing the trying to do the inode expansion.

Link: https://lore.kernel.org/r/20191110121510.GH23325@mit.edu
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com
Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

ext4: fix use-after-free race with debug_want_extra_isize

2020-01-23T07:18:36+00:00

commit 7bc04c5c2cc467c5b40f2b03ba08da174a0d5fa7 upstream.

When remounting with debug_want_extra_isize, we were not performing the
same checks that we do during a normal mount.  That allowed us to set a
value for s_want_extra_isize that reached outside the s_inode_size.

Fixes: e2b911c53584 ("ext4: clean up feature test macros with predicate functions")
Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com
Reviewed-by: Jan Kara 
Signed-off-by: Barret Rhoden 
Signed-off-by: Theodore Ts'o 
[bwh: Backported to 4.4: The debug_want_extra_isize mount option is not
 supported]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

mm/page_alloc.c: calculate 'available' memory in a separate function

2020-01-23T07:18:35+00:00

commit d02bd27bd33dd7e8d22594cd568b81be0cb584cd upstream.

Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.

It indicates to the hypervisor how big the balloon can be inflated
without pushing the guest system to swap.  This metric would be very
useful in VM orchestration software to improve memory management of
different VMs under overcommit.

This patch (of 2):

Factor out calculation of the available memory counter into a separate
exportable function, in order to be able to use it in other parts of the
kernel.

In particular, it appears a relevant metric to report to the hypervisor
via virtio-balloon statistics interface (in a followup patch).

Signed-off-by: Igor Redko 
Signed-off-by: Denis V. Lunev 
Reviewed-by: Roman Kagan 
Cc: Michael S. Tsirkin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 4.4 as dependency of commit a1078e821b60
 "xen: let alloc_xenballooned_pages() fail if not enough memory free"]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

chardev: Avoid potential use-after-free in 'chrdev_open()'

2020-01-14T19:03:00+00:00

commit 68faa679b8be1a74e6663c21c3a9d25d32f1c079 upstream.

'chrdev_open()' calls 'cdev_get()' to obtain a reference to the
'struct cdev *' stashed in the 'i_cdev' field of the target inode
structure. If the pointer is NULL, then it is initialised lazily by
looking up the kobject in the 'cdev_map' and so the whole procedure is
protected by the 'cdev_lock' spinlock to serialise initialisation of
the shared pointer.

Unfortunately, it is possible for the initialising thread to fail *after*
installing the new pointer, for example if the subsequent '->open()' call
on the file fails. In this case, 'cdev_put()' is called, the reference
count on the kobject is dropped and, if nobody else has taken a reference,
the release function is called which finally clears 'inode->i_cdev' from
'cdev_purge()' before potentially freeing the object. The problem here
is that a racing thread can happily take the 'cdev_lock' and see the
non-NULL pointer in the inode, which can result in a refcount increment
from zero and a warning:

  |  ------------[ cut here ]------------
  |  refcount_t: addition on 0; use-after-free.
  |  WARNING: CPU: 2 PID: 6385 at lib/refcount.c:25 refcount_warn_saturate+0x6d/0xf0
  |  Modules linked in:
  |  CPU: 2 PID: 6385 Comm: repro Not tainted 5.5.0-rc2+ #22
  |  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  |  RIP: 0010:refcount_warn_saturate+0x6d/0xf0
  |  Code: 05 55 9a 15 01 01 e8 9d aa c8 ff 0f 0b c3 80 3d 45 9a 15 01 00 75 ce 48 c7 c7 00 9c 62 b3 c6 08
  |  RSP: 0018:ffffb524c1b9bc70 EFLAGS: 00010282
  |  RAX: 0000000000000000 RBX: ffff9e9da1f71390 RCX: 0000000000000000
  |  RDX: ffff9e9dbbd27618 RSI: ffff9e9dbbd18798 RDI: ffff9e9dbbd18798
  |  RBP: 0000000000000000 R08: 000000000000095f R09: 0000000000000039
  |  R10: 0000000000000000 R11: ffffb524c1b9bb20 R12: ffff9e9da1e8c700
  |  R13: ffffffffb25ee8b0 R14: 0000000000000000 R15: ffff9e9da1e8c700
  |  FS:  00007f3b87d26700(0000) GS:ffff9e9dbbd00000(0000) knlGS:0000000000000000
  |  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  |  CR2: 00007fc16909c000 CR3: 000000012df9c000 CR4: 00000000000006e0
  |  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  |  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  |  Call Trace:
  |   kobject_get+0x5c/0x60
  |   cdev_get+0x2b/0x60
  |   chrdev_open+0x55/0x220
  |   ? cdev_put.part.3+0x20/0x20
  |   do_dentry_open+0x13a/0x390
  |   path_openat+0x2c8/0x1470
  |   do_filp_open+0x93/0x100
  |   ? selinux_file_ioctl+0x17f/0x220
  |   do_sys_open+0x186/0x220
  |   do_syscall_64+0x48/0x150
  |   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  |  RIP: 0033:0x7f3b87efcd0e
  |  Code: 89 54 24 08 e8 a3 f4 ff ff 8b 74 24 0c 48 8b 3c 24 41 89 c0 44 8b 54 24 08 b8 01 01 00 00 89 f4
  |  RSP: 002b:00007f3b87d259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
  |  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b87efcd0e
  |  RDX: 0000000000000000 RSI: 00007f3b87d25a80 RDI: 00000000ffffff9c
  |  RBP: 00007f3b87d25e90 R08: 0000000000000000 R09: 0000000000000000
  |  R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe188f504e
  |  R13: 00007ffe188f504f R14: 00007f3b87d26700 R15: 0000000000000000
  |  ---[ end trace 24f53ca58db8180a ]---

Since 'cdev_get()' can already fail to obtain a reference, simply move
it over to use 'kobject_get_unless_zero()' instead of 'kobject_get()',
which will cause the racing thread to return -ENXIO if the initialising
thread fails unexpectedly.

Cc: Hillf Danton 
Cc: Andrew Morton 
Cc: Al Viro 
Reported-by: syzbot+82defefbbd8527e1c2cb@syzkaller.appspotmail.com
Signed-off-by: Will Deacon 
Cc: stable 
Link: https://lore.kernel.org/r/20191219120203.32691-1-will@kernel.org
Signed-off-by: Greg Kroah-Hartman

pstore/ram: Write new dumps to start of recycled zones

2020-01-12T10:22:46+00:00

[ Upstream commit 9e5f1c19800b808a37fb9815a26d382132c26c3d ]

The ram_core.c routines treat przs as circular buffers. When writing a
new crash dump, the old buffer needs to be cleared so that the new dump
doesn't end up in the wrong place (i.e. at the end).

The solution to this problem is to reset the circular buffer state before
writing a new Oops dump.

Signed-off-by: Aleksandr Yashkin 
Signed-off-by: Nikolay Merinov 
Signed-off-by: Ariel Gilman 
Link: https://lore.kernel.org/r/20191223133816.28155-1-n.merinov@inango-systems.com
Fixes: 896fc1f0c4c6 ("pstore/ram: Switch to persistent_ram routines")
[kees: backport to v4.9]
Signed-off-by: Kees Cook 
Signed-off-by: Sasha Levin

locks: print unsigned ino in /proc/locks

2020-01-12T10:22:41+00:00

commit 98ca480a8f22fdbd768e3dad07024c8d4856576c upstream.

An ino is unsigned, so display it as such in /proc/locks.

Cc: stable@vger.kernel.org
Signed-off-by: Amir Goldstein 
Signed-off-by: Jeff Layton 
Signed-off-by: Greg Kroah-Hartman

xfs: fix mount failure crash on invalid iclog memory access

2020-01-12T10:22:40+00:00

[ Upstream commit 798a9cada4694ca8d970259f216cec47e675bfd5 ]

syzbot (via KASAN) reports a use-after-free in the error path of
xlog_alloc_log(). Specifically, the iclog freeing loop doesn't
handle the case of a fully initialized ->l_iclog linked list.
Instead, it assumes that the list is partially constructed and NULL
terminated.

This bug manifested because there was no possible error scenario
after iclog list setup when the original code was added.  Subsequent
code and associated error conditions were added some time later,
while the original error handling code was never updated. Fix up the
error loop to terminate either on a NULL iclog or reaching the end
of the list.

Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com
Signed-off-by: Brian Foster 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Sasha Levin

filldir[64]: remove WARN_ON_ONCE() for bad directory entries

2020-01-04T12:34:37+00:00

commit b9959c7a347d6adbb558fba7e36e9fef3cba3b07 upstream.

This was always meant to be a temporary thing, just for testing and to
see if it actually ever triggered.

The only thing that reported it was syzbot doing disk image fuzzing, and
then that warning is expected.  So let's just remove it before -rc4,
because the extra sanity testing should probably go to -stable, but we
don't want the warning to do so.

Reported-by: syzbot+3031f712c7ad5dd4d926@syzkaller.appspotmail.com
Fixes: 8a23eb804ca4 ("Make filldir[64]() verify the directory entry filename is valid")
Signed-off-by: Linus Torvalds 
Signed-off-by: Siddharth Chandrasekaran 
Signed-off-by: Greg Kroah-Hartman