Commit Graph

53526 Commits

Author SHA1 Message Date
Hugh Dickins
6c04ab0edd proc: fix smaps and meminfo alignment
The 4.17-rc /proc/meminfo and /proc/<pid>/smaps look ugly: single-digit
numbers (commonly 0) are misaligned.

Remove seq_put_decimal_ull_width()'s leftover optimization for single
digits: it's wrong now that num_to_str() takes care of the width.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805241554210.1326@eggly.anvils
Fixes: d1be35cb6f ("proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-25 18:12:11 -07:00
Changwei Ge
3373de209c ocfs2: revert "ocfs2/o2hb: check len for bio_add_page() to avoid getting incorrect bio"
This reverts commit ba16ddfbeb ("ocfs2/o2hb: check len for
bio_add_page() to avoid getting incorrect bio").

In my testing, this patch introduces a problem that mkfs can't have
slots more than 16 with 4k block size.

And the original logic is safe actually with the situation it mentions
so revert this commit.

Attach test log:
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 0, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 1, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 2, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 3, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 4, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 5, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 6, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 7, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 8, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 9, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 10, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 11, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 12, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 13, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 14, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 15, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 16, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:471 ERROR: Adding page[16] to bio failed, page ffffea0002d7ed40, len 0, vec_len 4096, vec_start 0,bi_sector 8192
  (mkfs.ocfs2,27479,2):o2hb_read_slots:500 ERROR: status = -5
  (mkfs.ocfs2,27479,2):o2hb_populate_slot_data:1911 ERROR: status = -5
  (mkfs.ocfs2,27479,2):o2hb_region_dev_write:2012 ERROR: status = -5

Link: http://lkml.kernel.org/r/SIXPR06MB0461721F398A5A92FC68C39ED5920@SIXPR06MB0461.apcprd06.prod.outlook.com
Signed-off-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-25 18:12:10 -07:00
Linus Torvalds
34b48b8789 Merge candidates for 4.17-rc
- Remove bouncing addresses from the MAINTAINERS file
 - Kernel oops and bad error handling fixes for hfi, i40iw, cxgb4, and hns drivers
 - Various small LOC behavioral/operational bugs in mlx5, hns, qedr and i40iw drivers
 - Two fixes for patches already sent during the merge window
 - A long standing bug related to not decreasing the pinned pages count in the right
   MM was found and fixed
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull rdma fixes from Jason Gunthorpe:
 "This is pretty much just the usual array of smallish driver bugs.

   - remove bouncing addresses from the MAINTAINERS file

   - kernel oops and bad error handling fixes for hfi, i40iw, cxgb4, and
     hns drivers

   - various small LOC behavioral/operational bugs in mlx5, hns, qedr
     and i40iw drivers

   - two fixes for patches already sent during the merge window

   - a long-standing bug related to not decreasing the pinned pages
     count in the right MM was found and fixed"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (28 commits)
  RDMA/hns: Move the location for initializing tmp_len
  RDMA/hns: Bugfix for cq record db for kernel
  IB/uverbs: Fix uverbs_attr_get_obj
  RDMA/qedr: Fix doorbell bar mapping for dpi > 1
  IB/umem: Use the correct mm during ib_umem_release
  iw_cxgb4: Fix an error handling path in 'c4iw_get_dma_mr()'
  RDMA/i40iw: Avoid panic when reading back the IRQ affinity hint
  RDMA/i40iw: Avoid reference leaks when processing the AEQ
  RDMA/i40iw: Avoid panic when objects are being created and destroyed
  RDMA/hns: Fix the bug with NULL pointer
  RDMA/hns: Set NULL for __internal_mr
  RDMA/hns: Enable inner_pa_vld filed of mpt
  RDMA/hns: Set desc_dma_addr for zero when free cmq desc
  RDMA/hns: Fix the bug with rq sge
  RDMA/hns: Not support qp transition from reset to reset for hip06
  RDMA/hns: Add return operation when configured global param fail
  RDMA/hns: Update convert function of endian format
  RDMA/hns: Load the RoCE dirver automatically
  RDMA/hns: Bugfix for rq record db for kernel
  RDMA/hns: Add rq inline flags judgement
  ...
2018-05-24 14:12:05 -07:00
Linus Torvalds
d7b66b4ab0 for-4.17-rc6-tag
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Merge tag 'for-4.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "A one-liner that prevents leaking an internal error value 1 out of the
  ftruncate syscall.

  This has been observed in practice. The steps to reproduce make a
  common pattern (open/write/fync/ftruncate) but also need the
  application to not check only for negative values and happens only for
  compressed inlined files.

  The conditions are narrow but as this could break userspace I think
  it's better to merge it now and not wait for the merge window"

* tag 'for-4.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix error handling in btrfs_truncate()
2018-05-24 11:47:43 -07:00
Omar Sandoval
d50147381a Btrfs: fix error handling in btrfs_truncate()
Jun Wu at Facebook reported that an internal service was seeing a return
value of 1 from ftruncate() on Btrfs in some cases. This is coming from
the NEED_TRUNCATE_BLOCK return value from btrfs_truncate_inode_items().

btrfs_truncate() uses two variables for error handling, ret and err.
When btrfs_truncate_inode_items() returns non-zero, we set err to the
return value. However, NEED_TRUNCATE_BLOCK is not an error. Make sure we
only set err if ret is an error (i.e., negative).

To reproduce the issue: mount a filesystem with -o compress-force=zstd
and the following program will encounter return value of 1 from
ftruncate:

int main(void) {
        char buf[256] = { 0 };
        int ret;
        int fd;

        fd = open("test", O_CREAT | O_WRONLY | O_TRUNC, 0666);
        if (fd == -1) {
                perror("open");
                return EXIT_FAILURE;
        }

        if (write(fd, buf, sizeof(buf)) != sizeof(buf)) {
                perror("write");
                close(fd);
                return EXIT_FAILURE;
        }

        if (fsync(fd) == -1) {
                perror("fsync");
                close(fd);
                return EXIT_FAILURE;
        }

        ret = ftruncate(fd, 128);
        if (ret) {
                printf("ftruncate() returned %d\n", ret);
                close(fd);
                return EXIT_FAILURE;
        }

        close(fd);
        return EXIT_SUCCESS;
}

Fixes: ddfae63cc8 ("btrfs: move btrfs_truncate_block out of trans handle")
CC: stable@vger.kernel.org # 4.15+
Reported-by: Jun Wu <quark@fb.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-24 11:56:57 +02:00
Linus Torvalds
5997aab0a1 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Assorted fixes all over the place"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: fix io_destroy(2) vs. lookup_ioctx() race
  ext2: fix a block leak
  nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed
  cachefiles: vfs_mkdir() might succeed leaving dentry negative unhashed
  unfuck sysfs_mount()
  kernfs: deal with kernfs_fill_super() failures
  cramfs: Fix IS_ENABLED typo
  befs_lookup(): use d_splice_alias()
  affs_lookup: switch to d_splice_alias()
  affs_lookup(): close a race with affs_remove_link()
  fix breakage caused by d_find_alias() semantics change
  fs: don't scan the inode cache before SB_BORN is set
  do d_instantiate/unlock_new_inode combinations safely
  iov_iter: fix memory leak in pipe_get_pages_alloc()
  iov_iter: fix return type of __pipe_get_pages()
2018-05-21 11:54:57 -07:00
Al Viro
baf10564fb aio: fix io_destroy(2) vs. lookup_ioctx() race
kill_ioctx() used to have an explicit RCU delay between removing the
reference from ->ioctx_table and percpu_ref_kill() dropping the refcount.
At some point that delay had been removed, on the theory that
percpu_ref_kill() itself contained an RCU delay.  Unfortunately, that was
the wrong kind of RCU delay and it didn't care about rcu_read_lock() used
by lookup_ioctx().  As the result, we could get ctx freed right under
lookup_ioctx().  Tejun has fixed that in a6d7cff472 ("fs/aio: Add explicit
RCU grace period when freeing kioctx"); however, that fix is not enough.

Suppose io_destroy() from one thread races with e.g. io_setup() from another;
CPU1 removes the reference from current->mm->ioctx_table[...] just as CPU2
has picked it (under rcu_read_lock()).  Then CPU1 proceeds to drop the
refcount, getting it to 0 and triggering a call of free_ioctx_users(),
which proceeds to drop the secondary refcount and once that reaches zero
calls free_ioctx_reqs().  That does
        INIT_RCU_WORK(&ctx->free_rwork, free_ioctx);
        queue_rcu_work(system_wq, &ctx->free_rwork);
and schedules freeing the whole thing after RCU delay.

In the meanwhile CPU2 has gotten around to percpu_ref_get(), bumping the
refcount from 0 to 1 and returned the reference to io_setup().

Tejun's fix (that queue_rcu_work() in there) guarantees that ctx won't get
freed until after percpu_ref_get().  Sure, we'd increment the counter before
ctx can be freed.  Now we are out of rcu_read_lock() and there's nothing to
stop freeing of the whole thing.  Unfortunately, CPU2 assumes that since it
has grabbed the reference, ctx is *NOT* going away until it gets around to
dropping that reference.

The fix is obvious - use percpu_ref_tryget_live() and treat failure as miss.
It's not costlier than what we currently do in normal case, it's safe to
call since freeing *is* delayed and it closes the race window - either
lookup_ioctx() comes before percpu_ref_kill() (in which case ctx->users
won't reach 0 until the caller of lookup_ioctx() drops it) or lookup_ioctx()
fails, ctx->users is unaffected and caller of lookup_ioctx() doesn't see
the object in question at all.

Cc: stable@kernel.org
Fixes: a6d7cff472 "fs/aio: Add explicit RCU grace period when freeing kioctx"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:11 -04:00
Al Viro
5aa1437d2d ext2: fix a block leak
open file, unlink it, then use ioctl(2) to make it immutable or
append only.  Now close it and watch the blocks *not* freed...

Immutable/append-only checks belong in ->setattr().
Note: the bug is old and backport to anything prior to 737f2e93b9
("ext2: convert to use the new truncate convention") will need
these checks lifted into ext2_setattr().

Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:11 -04:00
Al Viro
3819bb0d79 nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed
That can (and does, on some filesystems) happen - ->mkdir() (and thus
vfs_mkdir()) can legitimately leave its argument negative and just
unhash it, counting upon the lookup to pick the object we'd created
next time we try to look at that name.

Some vfs_mkdir() callers forget about that possibility...

Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:10 -04:00
Al Viro
9c3e9025a3 cachefiles: vfs_mkdir() might succeed leaving dentry negative unhashed
That can (and does, on some filesystems) happen - ->mkdir() (and thus
vfs_mkdir()) can legitimately leave its argument negative and just
unhash it, counting upon the lookup to pick the object we'd created
next time we try to look at that name.

Some vfs_mkdir() callers forget about that possibility...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:10 -04:00
Al Viro
7b745a4e40 unfuck sysfs_mount()
new_sb is left uninitialized in case of early failures in kernfs_mount_ns(),
and while IS_ERR(root) is true in all such cases, using IS_ERR(root) || !new_sb
is not a solution - IS_ERR(root) is true in some cases when new_sb is true.

Make sure new_sb is initialized (and matches the reality) in all cases and
fix the condition for dropping kobj reference - we want it done precisely
in those situations where the reference has not been transferred into a new
super_block instance.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:09 -04:00
Al Viro
82382acec0 kernfs: deal with kernfs_fill_super() failures
make sure that info->node is initialized early, so that kernfs_kill_sb()
can list_del() it safely.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:08 -04:00
Joe Perches
08a8f30868 cramfs: Fix IS_ENABLED typo
There's an extra C here...

Fixes: 99c18ce580 ("cramfs: direct memory access support")
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:08 -04:00
Al Viro
f4e4d434fe befs_lookup(): use d_splice_alias()
RTFS(Documentation/filesystems/nfs/Exporting) if you try to make
something exportable.

Fixes: ac632f5b63 "befs: add NFS export support"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:30:07 -04:00
Al Viro
87fbd639c0 affs_lookup: switch to d_splice_alias()
Making something exportable takes more than providing ->s_export_ops.
In particular, ->lookup() *MUST* use d_splice_alias() instead of
d_add().

Reading Documentation/filesystems/nfs/Exporting would've been a good idea;
as it is, exporting AFFS is badly (and exploitably) broken.

Partially-Fixes: ed4433d723 "fs/affs: make affs exportable"
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:29:12 -04:00
Al Viro
30da870ce4 affs_lookup(): close a race with affs_remove_link()
we unlock the directory hash too early - if we are looking at secondary
link and primary (in another directory) gets removed just as we unlock,
we could have the old primary moved in place of the secondary, leaving
us to look into freed entry (and leaving our dentry with ->d_fsdata
pointing to a freed entry).

Cc: stable@vger.kernel.org # 2.4.4+
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-21 14:27:45 -04:00
Linus Torvalds
3b78ce4a34 Merge branch 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Merge speculative store buffer bypass fixes from Thomas Gleixner:

 - rework of the SPEC_CTRL MSR management to accomodate the new fancy
   SSBD (Speculative Store Bypass Disable) bit handling.

 - the CPU bug and sysfs infrastructure for the exciting new Speculative
   Store Bypass 'feature'.

 - support for disabling SSB via LS_CFG MSR on AMD CPUs including
   Hyperthread synchronization on ZEN.

 - PRCTL support for dynamic runtime control of SSB

 - SECCOMP integration to automatically disable SSB for sandboxed
   processes with a filter flag for opt-out.

 - KVM integration to allow guests fiddling with SSBD including the new
   software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on
   AMD.

 - BPF protection against SSB

.. this is just the core and x86 side, other architecture support will
come separately.

* 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
  bpf: Prevent memory disambiguation attack
  x86/bugs: Rename SSBD_NO to SSB_NO
  KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
  x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
  x86/bugs: Rework spec_ctrl base and mask logic
  x86/bugs: Remove x86_spec_ctrl_set()
  x86/bugs: Expose x86_spec_ctrl_base directly
  x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
  x86/speculation: Rework speculative_store_bypass_update()
  x86/speculation: Add virtualized speculative store bypass disable support
  x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
  x86/speculation: Handle HT correctly on AMD
  x86/cpufeatures: Add FEATURE_ZEN
  x86/cpufeatures: Disentangle SSBD enumeration
  x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
  x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
  KVM: SVM: Move spec control call after restore of GS
  x86/cpu: Make alternative_msr_write work for 32-bit code
  x86/bugs: Fix the parameters alignment and missing void
  x86/bugs: Make cpu_show_common() static
  ...
2018-05-21 11:23:26 -07:00
Linus Torvalds
e5e03ad9e0 for-4.17-rc5-tag
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Merge tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "We've accumulated some fixes during the last week, some of them were
  in the works for a longer time but there are some newer ones too.

  Most of the fixes have a reproducer and fix user visible problems,
  also candidates for stable kernels. They IMHO qualify for a late rc,
  though I did not expect that many"

* tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix crash when trying to resume balance without the resume flag
  btrfs: Fix delalloc inodes invalidation during transaction abort
  btrfs: Split btrfs_del_delalloc_inode into 2 functions
  btrfs: fix reading stale metadata blocks after degraded raid1 mounts
  btrfs: property: Set incompat flag if lzo/zstd compression is set
  Btrfs: fix duplicate extents after fsync of file with prealloc extents
  Btrfs: fix xattr loss after power failure
  Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting
2018-05-20 12:04:27 -07:00
Tetsuo Handa
66072c2932 hfsplus: stop workqueue when fill_super() failed
syzbot is reporting ODEBUG messages at hfsplus_fill_super() [1].  This
is because hfsplus_fill_super() forgot to call cancel_delayed_work_sync().

As far as I can see, it is hfsplus_mark_mdb_dirty() from
hfsplus_new_inode() in hfsplus_fill_super() that calls
queue_delayed_work().  Therefore, I assume that hfsplus_new_inode() does
not fail if queue_delayed_work() was called, and the out_put_hidden_dir
label is the appropriate location to call cancel_delayed_work_sync().

[1] https://syzkaller.appspot.com/bug?id=a66f45e96fdbeb76b796bf46eb25ea878c42a6c9

Link: http://lkml.kernel.org/r/964a8b27-cd69-357c-fe78-76b066056201@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+4f2e5f086147d543ab03@syzkaller.appspotmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-18 17:17:12 -07:00
Willy Tarreau
7f7ccc2ccc proc: do not access cmdline nor environ from file-backed areas
proc_pid_cmdline_read() and environ_read() directly access the target
process' VM to retrieve the command line and environment. If this
process remaps these areas onto a file via mmap(), the requesting
process may experience various issues such as extra delays if the
underlying device is slow to respond.

Let's simply refuse to access file-backed areas in these functions.
For this we add a new FOLL_ANON gup flag that is passed to all calls
to access_remote_vm(). The code already takes care of such failures
(including unmapped areas). Accesses via /proc/pid/mem were not
changed though.

This was assigned CVE-2018-1120.

Note for stable backports: the patch may apply to kernels prior to 4.11
but silently miss one location; it must be checked that no call to
access_remote_vm() keeps zero as the last argument.

Reported-by: Qualys Security Advisory <qsa@qualys.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-17 09:27:47 -07:00
Anand Jain
02ee654d3a btrfs: fix crash when trying to resume balance without the resume flag
We set the BTRFS_BALANCE_RESUME flag in the btrfs_recover_balance()
only, which isn't called during the remount. So when resuming from
the paused balance we hit the bug:

 kernel: kernel BUG at fs/btrfs/volumes.c:3890!
 ::
 kernel:  balance_kthread+0x51/0x60 [btrfs]
 kernel:  kthread+0x111/0x130
 ::
 kernel: RIP: btrfs_balance+0x12e1/0x1570 [btrfs] RSP: ffffba7d0090bde8

Reproducer:
  On a mounted filesystem:

  btrfs balance start --full-balance /btrfs
  btrfs balance pause /btrfs
  mount -o remount,ro /dev/sdb /btrfs
  mount -o remount,rw /dev/sdb /btrfs

To fix this set the BTRFS_BALANCE_RESUME flag in
btrfs_resume_balance_async().

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:38:24 +02:00
Nikolay Borisov
fe816d0f1d btrfs: Fix delalloc inodes invalidation during transaction abort
When a transaction is aborted btrfs_cleanup_transaction is called to
cleanup all the various in-flight bits and pieces which migth be
active. One of those is delalloc inodes - inodes which have dirty
pages which haven't been persisted yet. Currently the process of
freeing such delalloc inodes in exceptional circumstances such as
transaction abort boiled down to calling btrfs_invalidate_inodes whose
sole job is to invalidate the dentries for all inodes related to a
root. This is in fact wrong and insufficient since such delalloc inodes
will likely have pending pages or ordered-extents and will be linked to
the sb->s_inode_list. This means that unmounting a btrfs instance with
an aborted transaction could potentially lead inodes/their pages
visible to the system long after their superblock has been freed. This
in turn leads to a "use-after-free" situation once page shrink is
triggered. This situation could be simulated by running generic/019
which would cause such inodes to be left hanging, followed by
generic/176 which causes memory pressure and page eviction which lead
to touching the freed super block instance. This situation is
additionally detected by the unmount code of VFS with the following
message:

"VFS: Busy inodes after unmount of Self-destruct in 5 seconds.  Have a nice day..."

Additionally btrfs hits WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
in free_fs_root for the same reason.

This patch aims to rectify the sitaution by doing the following:

1. Change btrfs_destroy_delalloc_inodes so that it calls
invalidate_inode_pages2 for every inode on the delalloc list, this
ensures that all the pages of the inode are released. This function
boils down to calling btrfs_releasepage. During test I observed cases
where inodes on the delalloc list were having an i_count of 0, so this
necessitates using igrab to be sure we are working on a non-freed inode.

2. Since calling btrfs_releasepage might queue delayed iputs move the
call out to btrfs_cleanup_transaction in btrfs_error_commit_super before
calling run_delayed_iputs for the last time. This is necessary to ensure
that delayed iputs are run.

Note: this patch is tagged for 4.14 stable but the fix applies to older
versions too but needs to be backported manually due to conflicts.

CC: stable@vger.kernel.org # 4.14.x: 2b87733134: btrfs: Split btrfs_del_delalloc_inode into 2 functions
CC: stable@vger.kernel.org # 4.14.x
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment to igrab ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:38:18 +02:00
Nikolay Borisov
2b87733134 btrfs: Split btrfs_del_delalloc_inode into 2 functions
This is in preparation of fixing delalloc inodes leakage on transaction
abort. Also export the new function.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:18:26 +02:00
Liu Bo
02a3307aa9 btrfs: fix reading stale metadata blocks after degraded raid1 mounts
If a btree block, aka. extent buffer, is not available in the extent
buffer cache, it'll be read out from the disk instead, i.e.

btrfs_search_slot()
  read_block_for_search()  # hold parent and its lock, go to read child
    btrfs_release_path()
    read_tree_block()  # read child

Unfortunately, the parent lock got released before reading child, so
commit 5bdd3536cb ("Btrfs: Fix block generation verification race") had
used 0 as parent transid to read the child block.  It forces
read_tree_block() not to check if parent transid is different with the
generation id of the child that it reads out from disk.

A simple PoC is included in btrfs/124,

0. A two-disk raid1 btrfs,

1. Right after mkfs.btrfs, block A is allocated to be device tree's root.

2. Mount this filesystem and put it in use, after a while, device tree's
   root got COW but block A hasn't been allocated/overwritten yet.

3. Umount it and reload the btrfs module to remove both disks from the
   global @fs_devices list.

4. mount -odegraded dev1 and write some data, so now block A is allocated
   to be a leaf in checksum tree.  Note that only dev1 has the latest
   metadata of this filesystem.

5. Umount it and mount it again normally (with both disks), since raid1
   can pick up one disk by the writer task's pid, if btrfs_search_slot()
   needs to read block A, dev2 which does NOT have the latest metadata
   might be read for block A, then we got a stale block A.

6. As parent transid is not checked, block A is marked as uptodate and
   put into the extent buffer cache, so the future search won't bother
   to read disk again, which means it'll make changes on this stale
   one and make it dirty and flush it onto disk.

To avoid the problem, parent transid needs to be passed to
read_tree_block().

In order to get a valid parent transid, we need to hold the parent's
lock until finishing reading child.

This patch needs to be slightly adapted for stable kernels, the
&first_key parameter added to read_tree_block() is from 4.16+
(581c176041). The fix is to replace 0 by 'gen'.

Fixes: 5bdd3536cb ("Btrfs: Fix block generation verification race")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:18:25 +02:00
Misono Tomohiro
1a63c198dd btrfs: property: Set incompat flag if lzo/zstd compression is set
Incompat flag of LZO/ZSTD compression should be set at:

 1. mount time (-o compress/compress-force)
 2. when defrag is done
 3. when property is set

Currently 3. is missing and this commit adds this.

This could lead to a filesystem that uses ZSTD but is not marked as
such. If a kernel without a ZSTD support encounteres a ZSTD compressed
extent, it will handle that but this could be confusing to the user.

Typically the filesystem is mounted with the ZSTD option, but the
discrepancy can arise when a filesystem is never mounted with ZSTD and
then the property on some file is set (and some new extents are
written). A simple mount with -o compress=zstd will fix that up on an
unpatched kernel.

Same goes for LZO, but this has been around for a very long time
(2.6.37) so it's unlikely that a pre-LZO kernel would be used.

Fixes: 5c1aab1dd5 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add user visible impact ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:18:25 +02:00
Filipe Manana
31d11b83b9 Btrfs: fix duplicate extents after fsync of file with prealloc extents
In commit 471d557afe ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay"), on fsync,  we started to always log all prealloc
extents beyond an inode's i_size in order to avoid losing them after a
power failure. However under some cases this can lead to the log replay
code to create duplicate extent items, with different lengths, in the
extent tree. That happens because, as of that commit, we can now log
extent items based on extent maps that are not on the "modified" list
of extent maps of the inode's extent map tree. Logging extent items based
on extent maps is used during the fast fsync path to save time and for
this to work reliably it requires that the extent maps are not merged
with other adjacent extent maps - having the extent maps in the list
of modified extents gives such guarantee.

Consider the following example, captured during a long run of fsstress,
which illustrates this problem.

We have inode 271, in the filesystem tree (root 5), for which all of the
following operations and discussion apply to.

A buffered write starts at offset 312391 with a length of 933471 bytes
(end offset at 1245862). At this point we have, for this inode, the
following extent maps with the their field values:

em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
      block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 376832, block_start 1106399232,
      block_len 376832, orig_block_len 376832
em C, start 417792, orig_start 417792, len 782336, block_start
      18446744073709551613, block_len 0, orig_block_len 0
em D, start 1200128, orig_start 1200128, len 835584, block_start
      1106776064, block_len 835584, orig_block_len 835584
em E, start 2035712, orig_start 2035712, len 245760, block_start
      1107611648, block_len 245760, orig_block_len 245760

Extent map A corresponds to a hole and extent maps D and E correspond to
preallocated extents.

Extent map D ends where extent map E begins (1106776064 + 835584 =
1107611648), but these extent maps were not merged because they are in
the inode's list of modified extent maps.

An fsync against this inode is made, which triggers the fast path
(BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback
of the data previously written using buffered IO, and when the respective
ordered extent finishes, btrfs_drop_extents() is called against the
(aligned) range 311296..1249279. This causes a split of extent map D at
btrfs_drop_extent_cache(), replacing extent map D with a new extent map
D', also added to the list of modified extents,  with the following
values:

em D', start 1249280, orig_start of 1200128,
       block_start 1106825216 (= 1106776064 + 1249280 - 1200128),
       orig_block_len 835584,
       block_len 786432 (835584 - (1249280 - 1200128))

Then, during the fast fsync, btrfs_log_changed_extents() is called and
extent maps D' and E are removed from the list of modified extents. The
flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged
clear_em_logging() is called on each of them, and that makes extent map E
to be merged with extent map D' (try_merge_map()), resulting in D' being
deleted and E adjusted to:

em E, start 1249280, orig_start 1200128, len 1032192,
      block_start 1106825216, block_len 1032192,
      orig_block_len 245760

A direct IO write at offset 1847296 and length of 360448 bytes (end offset
at 2207744) starts, and at that moment the following extent maps exist for
our inode:

em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
      block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
      block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
      block_len 937984, orig_block_len 937984
em E (prealloc), start 1249280, orig_start 1200128, len 1032192,
      block_start 1106825216, block_len 1032192, orig_block_len 245760

The dio write results in drop_extent_cache() being called twice. The first
time for a range that starts at offset 1847296 and ends at offset 2035711
(length of 188416), which results in a double split of extent map E,
replacing it with two new extent maps:

em F, start 1249280, orig_start 1200128, block_start 1106825216,
      block_len 598016, orig_block_len 598016
em G, start 2035712, orig_start 1200128, block_start 1107611648,
      block_len 245760, orig_block_len 1032192

It also creates a new extent map that represents a part of the requested
IO (through create_io_em()):

em H, start 1847296, len 188416, block_start 1107423232, block_len 188416

The second call to drop_extent_cache() has a range with a start offset of
2035712 and end offset of 2207743 (length of 172032). This leads to
replacing extent map G with a new extent map I with the following values:

em I, start 2207744, orig_start 1200128, block_start 1107783680,
      block_len 73728, orig_block_len 1032192

It also creates a new extent map that represents the second part of the
requested IO (through create_io_em()):

em J, start 2035712, len 172032, block_start 1107611648, block_len 172032

The dio write set the inode's i_size to 2207744 bytes.

After the dio write the inode has the following extent maps:

em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
      block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
      block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
      block_len 937984, orig_block_len 937984
em F, start 1249280, orig_start 1200128, len 598016,
      block_start 1106825216, block_len 598016, orig_block_len 598016
em H, start 1847296, orig_start 1200128, len 188416,
      block_start 1107423232, block_len 188416, orig_block_len 835584
em J, start 2035712, orig_start 2035712, len 172032,
      block_start 1107611648, block_len 172032, orig_block_len 245760
em I, start 2207744, orig_start 1200128, len 73728,
      block_start 1107783680, block_len 73728, orig_block_len 1032192

Now do some change to the file, like adding a xattr for example and then
fsync it again. This triggers a fast fsync path, and as of commit
471d557afe ("Btrfs: fix loss of prealloc extents past i_size after fsync
log replay"), we use the extent map I to log a file extent item because
it's a prealloc extent and it starts at an offset matching the inode's
i_size. However when we log it, we create a file extent item with a value
for the disk byte location that is wrong, as can be seen from the
following output of "btrfs inspect-internal dump-tree":

 item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53
     generation 22 type 2 (prealloc)
     prealloc data disk byte 1106776064 nr 1032192
     prealloc data offset 1007616 nr 73728

Here the disk byte value corresponds to calculation based on some fields
from the extent map I:

  1106776064 = block_start (1107783680) - 1007616 (extent_offset)
  extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616

The disk byte value of 1106776064 clashes with disk byte values of the
file extent items at offsets 1249280 and 1847296 in the fs tree:

        item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53
                generation 20 type 2 (prealloc)
                prealloc data disk byte 1106776064 nr 835584
                prealloc data offset 49152 nr 598016
        item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53
                generation 20 type 1 (regular)
                extent data disk byte 1106776064 nr 835584
                extent data offset 647168 nr 188416 ram 835584
                extent compression 0 (none)
        item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53
                generation 20 type 1 (regular)
                extent data disk byte 1107611648 nr 245760
                extent data offset 0 nr 172032 ram 245760
                extent compression 0 (none)
        item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53
                generation 20 type 2 (prealloc)
                prealloc data disk byte 1107611648 nr 245760
                prealloc data offset 172032 nr 73728

Instead of the disk byte value of 1106776064, the value of 1107611648
should have been logged. Also the data offset value should have been
172032 and not 1007616.
After a log replay we end up getting two extent items in the extent tree
with different lengths, one of 835584, which is correct and existed
before the log replay, and another one of 1032192 which is wrong and is
based on the logged file extent item:

 item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53
    refs 2 gen 15 flags DATA
    extent data backref root 5 objectid 271 offset 1200128 count 2
 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53
    refs 1 gen 22 flags DATA
    extent data backref root 5 objectid 271 offset 1200128 count 1

Obviously this leads to many problems and a filesystem check reports many
errors:

 (...)
 checking extents
 Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1
 extent item 1106776064 has multiple extent items
 ref mismatch on [1106776064 835584] extent item 2, found 3
 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680
 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree
 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70
 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192
 backpointer mismatch on [1106776064 835584]
 checking free space cache
 block group 1103101952 has wrong amount of free space
 failed to load free space cache for block group 1103101952
 checking fs roots
 (...)

So fix this by logging the prealloc extents beyond the inode's i_size
based on searches in the subvolume tree instead of the extent maps.

Fixes: 471d557afe ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 14:18:19 +02:00
Linus Torvalds
21b9f1c7e3 AFS fixes
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Merge tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS fixes from David Howells:
 "Here's a set of patches that fix a number of bugs in the in-kernel AFS
  client, including:

   - Fix directory locking to not use individual page locks for
     directory reading/scanning but rather to use a semaphore on the
     afs_vnode struct as the directory contents must be read in a single
     blob and data from different reads must not be mixed as the entire
     contents may be shuffled about between reads.

   - Fix address list parsing to handle port specifiers correctly.

   - Only give up callback records on a server if we actually talked to
     that server (we might not be able to access a server).

   - Fix some callback handling bugs, including refcounting,
     whole-volume callbacks and when callbacks actually get broken in
     response to a CB.CallBack op.

   - Fix some server/address rotation bugs, including giving up if we
     can't probe a server; giving up if a server says it doesn't have a
     volume, but there are more servers to try.

   - Fix the decoding of fetched statuses to be OpenAFS compatible.

   - Fix the handling of server lookups in Cache Manager ops (such as
     CB.InitCallBackState3) to use a UUID if possible and to handle no
     server being found.

   - Fix a bug in server lookup where not all addresses are compared.

   - Fix the non-encryption of calls that prevents some servers from
     being accessed (this also requires an AF_RXRPC patch that has
     already gone in through the net tree).

  There's also a patch that adds tracepoints to log Cache Manager ops
  that don't find a matching server, either by UUID or by address"

* tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Fix the non-encryption of calls
  afs: Fix CB.CallBack handling
  afs: Fix whole-volume callback handling
  afs: Fix afs_find_server search loop
  afs: Fix the handling of an unfound server in CM operations
  afs: Add a tracepoint to record callbacks from unlisted servers
  afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID
  afs: Fix VNOVOL handling in address rotation
  afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility
  afs: Fix server rotation's handling of fileserver probe failure
  afs: Fix refcounting in callback registration
  afs: Fix giving up callbacks on server destruction
  afs: Fix address list parsing
  afs: Fix directory page locking
2018-05-15 10:48:36 -07:00
Filipe Manana
9a8fca62aa Btrfs: fix xattr loss after power failure
If a file has xattrs, we fsync it, to ensure we clear the flags
BTRFS_INODE_NEEDS_FULL_SYNC and BTRFS_INODE_COPY_EVERYTHING from its
inode, the current transaction commits and then we fsync it (without
either of those bits being set in its inode), we end up not logging
all its xattrs. This results in deleting all xattrs when replying the
log after a power failure.

Trivial reproducer

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ touch /mnt/foobar
  $ setfattr -n user.xa -v qwerty /mnt/foobar
  $ xfs_io -c "fsync" /mnt/foobar

  $ sync

  $ xfs_io -c "pwrite -S 0xab 0 64K" /mnt/foobar
  $ xfs_io -c "fsync" /mnt/foobar
  <power failure>

  $ mount /dev/sdb /mnt
  $ getfattr --absolute-names --dump /mnt/foobar
  <empty output>
  $

So fix this by making sure all xattrs are logged if we log a file's inode
item and neither the flags BTRFS_INODE_NEEDS_FULL_SYNC nor
BTRFS_INODE_COPY_EVERYTHING were set in the inode.

Fixes: 36283bf777 ("Btrfs: fix fsync xattr loss in the fast fsync path")
Cc: <stable@vger.kernel.org> # 4.2+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 16:42:43 +02:00
Robbie Ko
6f2f0b394b Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting
[BUG]
btrfs incremental send BUG happens when creating a snapshot of snapshot
that is being used by send.

[REASON]
The problem can happen if while we are doing a send one of the snapshots
used (parent or send) is snapshotted, because snapshoting implies COWing
the root of the source subvolume/snapshot.

1. When doing an incremental send, the send process will get the commit
   roots from the parent and send snapshots, and add references to them
   through extent_buffer_get().

2. When a snapshot/subvolume is snapshotted, its root node is COWed
   (transaction.c:create_pending_snapshot()).

3. COWing releases the space used by the node immediately, through:

   __btrfs_cow_block()
   --btrfs_free_tree_block()
   ----btrfs_add_free_space(bytenr of node)

4. Because send doesn't hold a transaction open, it's possible that
   the transaction used to create the snapshot commits, switches the
   commit root and the old space used by the previous root node gets
   assigned to some other node allocation. Allocation of a new node will
   use the existing extent buffer found in memory, which we previously
   got a reference through extent_buffer_get(), and allow the extent
   buffer's content (pages) to be modified:

   btrfs_alloc_tree_block
   --btrfs_reserve_extent
   ----find_free_extent (get bytenr of old node)
   --btrfs_init_new_buffer (use bytenr of old node)
   ----btrfs_find_create_tree_block
   ------alloc_extent_buffer
   --------find_extent_buffer (get old node)

5. So send can access invalid memory content and have unpredictable
   behaviour.

[FIX]
So we fix the problem by copying the commit roots of the send and
parent snapshots and use those copies.

CallTrace looks like this:
 ------------[ cut here ]------------
 kernel BUG at fs/btrfs/ctree.c:1861!
 invalid opcode: 0000 [#1] SMP
 CPU: 6 PID: 24235 Comm: btrfs Tainted: P           O 3.10.105 #23721
 ffff88046652d680 ti: ffff88041b720000 task.ti: ffff88041b720000
 RIP: 0010:[<ffffffffa08dd0e8>] read_node_slot+0x108/0x110 [btrfs]
 RSP: 0018:ffff88041b723b68  EFLAGS: 00010246
 RAX: ffff88043ca6b000 RBX: ffff88041b723c50 RCX: ffff880000000000
 RDX: 000000000000004c RSI: ffff880314b133f8 RDI: ffff880458b24000
 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88041b723c66
 R10: 0000000000000001 R11: 0000000000001000 R12: ffff8803f3e48890
 R13: ffff8803f3e48880 R14: ffff880466351800 R15: 0000000000000001
 FS:  00007f8c321dc8c0(0000) GS:ffff88047fcc0000(0000)
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 R2: 00007efd1006d000 CR3: 0000000213a24000 CR4: 00000000003407e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Stack:
 ffff88041b723c50 ffff8803f3e48880 ffff8803f3e48890 ffff8803f3e48880
 ffff880466351800 0000000000000001 ffffffffa08dd9d7 ffff88041b723c50
 ffff8803f3e48880 ffff88041b723c66 ffffffffa08dde85 a9ff88042d2c4400
 Call Trace:
 [<ffffffffa08dd9d7>] ? tree_move_down.isra.33+0x27/0x50 [btrfs]
 [<ffffffffa08dde85>] ? tree_advance+0xb5/0xc0 [btrfs]
 [<ffffffffa08e83d4>] ? btrfs_compare_trees+0x2d4/0x760 [btrfs]
 [<ffffffffa0982050>] ? finish_inode_if_needed+0x870/0x870 [btrfs]
 [<ffffffffa09841ea>] ? btrfs_ioctl_send+0xeda/0x1050 [btrfs]
 [<ffffffffa094bd3d>] ? btrfs_ioctl+0x1e3d/0x33f0 [btrfs]
 [<ffffffff81111133>] ? handle_pte_fault+0x373/0x990
 [<ffffffff8153a096>] ? atomic_notifier_call_chain+0x16/0x20
 [<ffffffff81063256>] ? set_task_cpu+0xb6/0x1d0
 [<ffffffff811122c3>] ? handle_mm_fault+0x143/0x2a0
 [<ffffffff81539cc0>] ? __do_page_fault+0x1d0/0x500
 [<ffffffff81062f07>] ? check_preempt_curr+0x57/0x90
 [<ffffffff8115075a>] ? do_vfs_ioctl+0x4aa/0x990
 [<ffffffff81034f83>] ? do_fork+0x113/0x3b0
 [<ffffffff812dd7d7>] ? trace_hardirqs_off_thunk+0x3a/0x6c
 [<ffffffff81150cc8>] ? SyS_ioctl+0x88/0xa0
 [<ffffffff8153e422>] ? system_call_fastpath+0x16/0x1b
 ---[ end trace 29576629ee80b2e1 ]---

Fixes: 7069830a9e ("Btrfs: add btrfs_compare_trees function")
CC: stable@vger.kernel.org # 3.6+
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 16:42:34 +02:00
David Howells
4776cab43f afs: Fix the non-encryption of calls
Some AFS servers refuse to accept unencrypted traffic, so can't be accessed
with kAFS.  Set the AF_RXRPC security level to encrypt client calls to deal
with this.

Note that incoming service calls are set by the remote client and so aren't
affected by this.

This requires an AF_RXRPC patch to pass the value set by setsockopt to calls
begun by the kernel.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:19 +01:00
David Howells
428edade4e afs: Fix CB.CallBack handling
The handling of CB.CallBack messages sent by the fileserver to the client
is broken in that they are currently being processed after the reply has
been transmitted.

This is not what the fileserver expects, however.  It holds up change
visibility until the reply comes so as to maintain cache coherency, and so
expects the client to have to refetch the state on the affected files.

Fix CB.CallBack handling to perform the callback break before sending the
reply.

The fileserver is free to hold up status fetches issued by other threads on
the same client that occur in reponse to the callback until any pending
changes have been committed.

Fixes: d001648ec7 ("rxrpc: Don't expose skbs to in-kernel users [ver #2]")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:19 +01:00
David Howells
68251f0a68 afs: Fix whole-volume callback handling
It's possible for an AFS file server to issue a whole-volume notification
that callbacks on all the vnodes in the file have been broken.  This is
done for R/O and backup volumes (which don't have per-file callbacks) and
for things like a volume being taken offline.

Fix callback handling to detect whole-volume notifications, to track it
across operations and to check it during inode validation.

Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
Marc Dionne
f9c1bba3d3 afs: Fix afs_find_server search loop
The code that looks up servers by addresses makes the assumption
that the list of addresses for a server is sorted.  It exits the
loop if it finds that the target address is larger than the
current candidate.  As the list is not currently sorted, this
can lead to a failure to find a matching server, which can cause
callbacks from that server to be ignored.

Remove the early exit case so that the complete list is searched.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
a86b06d1cc afs: Fix the handling of an unfound server in CM operations
If the client cache manager operations that need the server record
(CB.Callback, CB.InitCallBackState, and CB.InitCallBackState3) can't find
the server record, they abort the call from the file server with
RX_CALL_DEAD when they should return okay.

Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
3709a399c1 afs: Add a tracepoint to record callbacks from unlisted servers
Add a tracepoint to record callbacks from servers for which we don't have a
record.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
001ab5a67e afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID
Fix the handling of the CB.InitCallBackState3 service call to find the
record of a server that we're using by looking it up by the UUID passed as
the parameter rather than by its address (of which it might have many, and
which may change).

Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
3d9fa91161 afs: Fix VNOVOL handling in address rotation
If a volume location record lists multiple file servers for a volume, then
it's possible that due to a misconfiguration or a changing configuration
that one of the file servers doesn't know about it yet and will abort
VNOVOL.  Currently, the rotation algorithm will stop with EREMOTEIO.

Fix this by moving on to try the next server if VNOVOL is returned.  Once
all the servers have been tried and the record rechecked, the algorithm
will stop with EREMOTEIO or ENOMEDIUM.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
684b0f68cf afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility
The OpenAFS server's RXAFS_InlineBulkStatus implementation has a bug
whereby if an error occurs on one of the vnodes being queried, then the
errorCode field is set correctly in the corresponding status, but the
interfaceVersion field is left unset.

Fix kAFS to deal with this by evaluating the AFSFetchStatus blob against
the following cases when called from FS.InlineBulkStatus delivery:

 (1) If InterfaceVersion == 0 then:

     (a) If errorCode != 0 then it indicates the abort code for the
         corresponding vnode.

     (b) If errorCode == 0 then the status record is invalid.

 (2) If InterfaceVersion == 1 then:

     (a) If errorCode != 0 then it indicates the abort code for the
         corresponding vnode.

     (b) If errorCode == 0 then the status record is valid and can be
     	 parsed.

 (3) If InterfaceVersion is anything else then the status record is
     invalid.

Fixes: dd9fbcb8e1 ("afs: Rearrange status mapping")
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
ec5a3b4b50 afs: Fix server rotation's handling of fileserver probe failure
The server rotation algorithm just gives up if it fails to probe a
fileserver.  Fix this by rotating to the next fileserver instead.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 13:26:44 +01:00
David Howells
d4a96bec7a afs: Fix refcounting in callback registration
The refcounting on afs_cb_interest struct objects in
afs_register_server_cb_interest() is wrong as it uses the server list
entry's call back interest pointer without regard for the fact that it
might be replaced at any time and the object thrown away.

Fix this by:

 (1) Put a lock on the afs_server_list struct that can be used to
     mediate access to the callback interest pointers in the servers array.

 (2) Keep a ref on the callback interest that we get from the entry.

 (3) Dropping the old reference held by vnode->cb_interest if we replace
     the pointer.

Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 13:17:35 +01:00
David Howells
f2686b0926 afs: Fix giving up callbacks on server destruction
When a server record is destroyed, we want to send a message to the server
telling it that we're giving up all the callbacks it has promised us.

Apply two fixes to this:

 (1) Only send the FS.GiveUpAllCallBacks message if we actually got a
     callback from that server.  We assume this to be the case if we
     performed at least one successful FS operation on that server.

 (2) Send it to the address last used for that server rather than always
     picking the first address in the list (which might be unreachable).

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 13:17:35 +01:00
David Howells
01fd79e6de afs: Fix address list parsing
The parsing of port specifiers in the address list obtained from the DNS
resolution upcall doesn't work as in4_pton() and in6_pton() will fail on
encountering an unexpected delimiter (in this case, the '+' marking the
port number).  However, in*_pton() can't be given multiple specifiers.

Fix this by finding the delimiter in advance and not relying on in*_pton()
to find the end of the address for us.

Fixes: 8b2a464ced ("afs: Add an address list concept")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 13:17:35 +01:00
David Howells
b61f7dcf4e afs: Fix directory page locking
The afs directory loading code (primarily afs_read_dir()) locks all the
pages that hold a directory's content blob to defend against
getdents/getdents races and getdents/lookup races where the competitors
issue conflicting reads on the same data.  As the reads will complete
consecutively, they may retrieve different versions of the data and
one may overwrite the data that the other is busy parsing.

Fix this by not locking the pages at all, but rather by turning the
validation lock into an rwsem and getting an exclusive lock on it whilst
reading the data or validating the attributes and a shared lock whilst
parsing the data.  Sharing the attribute validation lock should be fine as
the data fetch will retrieve the attributes also.

The individual page locks aren't needed at all as the only place they're
being used is to serialise data loading.

Without this patch, the:

 	if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
		...
	}

part of afs_read_dir() may be skipped, leaving the pages unlocked when we
hit the success: clause - in which case we try to unlock the not-locked
pages, leading to the following oops:

  page:ffffe38b405b4300 count:3 mapcount:0 mapping:ffff98156c83a978 index:0x0
  flags: 0xfffe000001004(referenced|private)
  raw: 000fffe000001004 ffff98156c83a978 0000000000000000 00000003ffffffff
  raw: dead000000000100 dead000000000200 0000000000000001 ffff98156b27c000
  page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
  page->mem_cgroup:ffff98156b27c000
  ------------[ cut here ]------------
  kernel BUG at mm/filemap.c:1205!
  ...
  RIP: 0010:unlock_page+0x43/0x50
  ...
  Call Trace:
   afs_dir_iterate+0x789/0x8f0 [kafs]
   ? _cond_resched+0x15/0x30
   ? kmem_cache_alloc_trace+0x166/0x1d0
   ? afs_do_lookup+0x69/0x490 [kafs]
   ? afs_do_lookup+0x101/0x490 [kafs]
   ? key_default_cmp+0x20/0x20
   ? request_key+0x3c/0x80
   ? afs_lookup+0xf1/0x340 [kafs]
   ? __lookup_slow+0x97/0x150
   ? lookup_slow+0x35/0x50
   ? walk_component+0x1bf/0x490
   ? path_lookupat.isra.52+0x75/0x200
   ? filename_lookup.part.66+0xa0/0x170
   ? afs_end_vnode_operation+0x41/0x60 [kafs]
   ? __check_object_size+0x9c/0x171
   ? strncpy_from_user+0x4a/0x170
   ? vfs_statx+0x73/0xe0
   ? __do_sys_newlstat+0x39/0x70
   ? __x64_sys_getdents+0xc9/0x140
   ? __x64_sys_getdents+0x140/0x140
   ? do_syscall_64+0x5b/0x160
   ? entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: f3ddee8dc4 ("afs: Fix directory handling")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 13:17:35 +01:00
Linus Torvalds
ccda3c4b77 some small SMB3 fixes for 4.17-rc5, some for stable
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Merge tag '4.17-rc4-SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Some small SMB3 fixes for 4.17-rc5, some for stable"

* tag '4.17-rc4-SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: directory sync should not return an error
  cifs: smb2ops: Fix listxattr() when there are no EAs
  cifs: smbd: Enable signing with smbdirect
  cifs: Allocate validate negotiation request through kmalloc
2018-05-12 18:49:53 -07:00
Linus Torvalds
f0ab773f5c Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  rbtree: include rcu.h
  scripts/faddr2line: fix error when addr2line output contains discriminator
  ocfs2: take inode cluster lock before moving reflinked inode from orphan dir
  mm, oom: fix concurrent munlock and oom reaper unmap, v3
  mm: migrate: fix double call of radix_tree_replace_slot()
  proc/kcore: don't bounds check against address 0
  mm: don't show nr_indirectly_reclaimable in /proc/vmstat
  mm: sections are not offlined during memory hotremove
  z3fold: fix reclaim lock-ups
  init: fix false positives in W+X checking
  lib/find_bit_benchmark.c: avoid soft lockup in test_find_first_bit()
  KASAN: prohibit KASAN+STRUCTLEAK combination
  MAINTAINERS: update Shuah's email address
2018-05-11 18:04:12 -07:00
Ashish Samant
e438302920 ocfs2: take inode cluster lock before moving reflinked inode from orphan dir
While reflinking an inode, we create a new inode in orphan directory,
then take EX lock on it, reflink the original inode to orphan inode and
release EX lock.  Once the lock is released another node could request
it in EX mode from ocfs2_recover_orphans() which causes downconvert of
the lock, on this node, to NL mode.

Later we attempt to initialize security acl for the orphan inode and
move it to the reflink destination.  However, while doing this we dont
take EX lock on the inode.  This could potentially cause problems
because we could be starting transaction, accessing journal and
modifying metadata of the inode while holding NL lock and with another
node holding EX lock on the inode.

Fix this by taking orphan inode cluster lock in EX mode before
initializing security and moving orphan inode to reflink destination.
Use the __tracker variant while taking inode lock to avoid recursive
locking in the ocfs2_init_security_and_acl() call chain.

Link: http://lkml.kernel.org/r/1523475107-7639-1-git-send-email-ashish.samant@oracle.com
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-11 17:28:45 -07:00
Laura Abbott
3955333df9 proc/kcore: don't bounds check against address 0
The existing kcore code checks for bad addresses against __va(0) with
the assumption that this is the lowest address on the system.  This may
not hold true on some systems (e.g.  arm64) and produce overflows and
crashes.  Switch to using other functions to validate the address range.

It's currently only seen on arm64 and it's not clear if anyone wants to
use that particular combination on a stable release.  So this is not
urgent for stable.

Link: http://lkml.kernel.org/r/20180501201143.15121-1-labbott@redhat.com
Signed-off-by: Laura Abbott <labbott@redhat.com>
Tested-by: Dave Anderson <anderson@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-11 17:28:45 -07:00
Dave Chinner
79f546a696 fs: don't scan the inode cache before SB_BORN is set
We recently had an oops reported on a 4.14 kernel in
xfs_reclaim_inodes_count() where sb->s_fs_info pointed to garbage
and so the m_perag_tree lookup walked into lala land.  It produces
an oops down this path during the failed mount:

  radix_tree_gang_lookup_tag+0xc4/0x130
  xfs_perag_get_tag+0x37/0xf0
  xfs_reclaim_inodes_count+0x32/0x40
  xfs_fs_nr_cached_objects+0x11/0x20
  super_cache_count+0x35/0xc0
  shrink_slab.part.66+0xb1/0x370
  shrink_node+0x7e/0x1a0
  try_to_free_pages+0x199/0x470
  __alloc_pages_slowpath+0x3a1/0xd20
  __alloc_pages_nodemask+0x1c3/0x200
  cache_grow_begin+0x20b/0x2e0
  fallback_alloc+0x160/0x200
  kmem_cache_alloc+0x111/0x4e0

The problem is that the superblock shrinker is running before the
filesystem structures it depends on have been fully set up. i.e.
the shrinker is registered in sget(), before ->fill_super() has been
called, and the shrinker can call into the filesystem before
fill_super() does it's setup work. Essentially we are exposed to
both use-after-free and use-before-initialisation bugs here.

To fix this, add a check for the SB_BORN flag in super_cache_count.
In general, this flag is not set until ->fs_mount() completes
successfully, so we know that it is set after the filesystem
setup has completed. This matches the trylock_super() behaviour
which will not let super_cache_scan() run if SB_BORN is not set, and
hence will not allow the superblock shrinker from entering the
filesystem while it is being set up or after it has failed setup
and is being torn down.

Cc: stable@kernel.org
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-11 15:37:57 -04:00
Al Viro
1e2e547a93 do d_instantiate/unlock_new_inode combinations safely
For anything NFS-exported we do _not_ want to unlock new inode
before it has grown an alias; original set of fixes got the
ordering right, but missed the nasty complication in case of
lockdep being enabled - unlock_new_inode() does
	lockdep_annotate_inode_mutex_key(inode)
which can only be done before anyone gets a chance to touch
->i_mutex.  Unfortunately, flipping the order and doing
unlock_new_inode() before d_instantiate() opens a window when
mkdir can race with open-by-fhandle on a guessed fhandle, leading
to multiple aliases for a directory inode and all the breakage
that follows from that.

	Correct solution: a new primitive (d_instantiate_new())
combining these two in the right order - lockdep annotate, then
d_instantiate(), then the rest of unlock_new_inode().  All
combinations of d_instantiate() with unlock_new_inode() should
be converted to that.

Cc: stable@kernel.org	# 2.6.29 and later
Tested-by: Mike Marshall <hubcap@omnibond.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-11 15:36:37 -04:00
Steve French
6e70c267e6 smb3: directory sync should not return an error
As with NFS, which ignores sync on directory handles,
fsync on a directory handle is a noop for CIFS/SMB3.
Do not return an error on it.  It breaks some database
apps otherwise.

Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-05-10 19:21:14 -05:00