Commit Graph

44152 Commits

Author SHA1 Message Date
Vivek Goyal
21765194ce ovl: Do d_type check only if work dir creation was successful
d_type check requires successful creation of workdir as iterates
through work dir and expects work dir to be present in it. If that's
not the case, this check will always return d_type not supported even
if underlying filesystem might be supporting it.

So don't do this check if work dir creation failed in previous step.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-27 10:18:56 +02:00
Antonio Murdaca
3fe6e52f06 ovl: override creds with the ones from the superblock mounter
In user namespace the whiteout creation fails with -EPERM because the
current process isn't capable(CAP_SYS_ADMIN) when setting xattr.

A simple reproducer:

$ mkdir upper lower work merged lower/dir
$ sudo mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
$ unshare -m -p -f -U -r bash

Now as root in the user namespace:

\# touch merged/dir/{1,2,3} # this will force a copy up of lower/dir
\# rm -fR merged/*

This ends up failing with -EPERM after the files in dir has been
correctly deleted:

unlinkat(4, "2", 0)                     = 0
unlinkat(4, "1", 0)                     = 0
unlinkat(4, "3", 0)                     = 0
close(4)                                = 0
unlinkat(AT_FDCWD, "merged/dir", AT_REMOVEDIR) = -1 EPERM (Operation not
permitted)

Interestingly, if you don't place files in merged/dir you can remove it,
meaning if upper/dir does not exist, creating the char device file works
properly in that same location.

This patch uses ovl_sb_creator_cred() to get the cred struct from the
superblock mounter and override the old cred with these new ones so that
the whiteout creation is possible because overlay is wrong in assuming that
the creds it will get with prepare_creds will be in the initial user
namespace.  The old cap_raise game is removed in favor of just overriding
the old cred struct.

This patch also drops from ovl_copy_up_one() the following two lines:

override_cred->fsuid = stat->uid;
override_cred->fsgid = stat->gid;

This is because the correct uid and gid are taken directly with the stat
struct and correctly set with ovl_set_attr().

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-27 08:55:26 +02:00
Linus Torvalds
6ba5b85fd4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Overlayfs fixes from Miklos, assorted fixes from me.

  Stable fodder of varying severity, all sat in -next for a while"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ovl: ignore permissions on underlying lookup
  vfs: add lookup_hash() helper
  vfs: rename: check backing inode being equal
  vfs: add vfs_select_inode() helper
  get_rock_ridge_filename(): handle malformed NM entries
  ecryptfs: fix handling of directory opening
  atomic_open(): fix the handling of create_error
  fix the copy vs. map logics in blk_rq_map_user_iov()
  do_splice_to(): cap the size before passing to ->splice_read()
2016-05-14 11:59:43 -07:00
Linus Torvalds
1410b74e40 Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "During v4.6-rc1 cgroup namespace support was merged.  There is an
  issue where it's impossible to tell whether a given cgroup mount point
  is bind mounted or namespaced.  Serge has been working on the issue
  but it took longer than expected to resolve, so the late pull request.

  Given that it's a completely new feature and the patches don't touch
  anything else, the risk seems acceptable.  However, if this is too
  late, an alternative is plugging new cgroup ns creation for v4.6 and
  retrying for v4.7"

* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix compile warning
  kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call
  cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
  kernfs_path_from_node_locked: don't overwrite nlen
2016-05-13 16:26:46 -07:00
Junxiao Bi
c25a1e0671 ocfs2: fix posix_acl_create deadlock
Commit 702e5bc68a ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create.  The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs.  For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again.  This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted.  And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.

Fixes: 702e5bc68a ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@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>
2016-05-12 15:52:50 -07:00
Junxiao Bi
5ee0fbd50f ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
Commit 743b5f1434 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
introduced this issue.  ocfs2_setattr called by chmod command holds
cluster wide inode lock when calling posix_acl_chmod.  This latter
function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl.  These
two are also called directly from vfs layer for getfacl/setfacl commands
and therefore acquire the cluster wide inode lock.  If a remote
conversion request comes after the first inode lock in ocfs2_setattr,
OCFS2_LOCK_BLOCKED will be set.  And this will cause the second call to
inode lock from the ocfs2_iop_get_acl() to block indefinetly.

The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which
does not call back into the filesystem.  Therefore, we restore
ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that
instead.

Fixes: 743b5f1434 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@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>
2016-05-12 15:52:50 -07:00
Serge E. Hallyn
3cc9b23c81 kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call
Our caller expects 0 on success, not >0.

This fixes a bug in the patch

	cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces

where /sys does not show up in mountinfo, breaking criu.

Thanks for catching this, Andrei.

Reported-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-12 11:03:51 -04:00
Al Viro
e4d35be584 Merge branch 'ovl-fixes' into for-linus 2016-05-11 00:00:29 -04:00
Miklos Szeredi
38b78a5f18 ovl: ignore permissions on underlying lookup
Generally permission checking is not necessary when overlayfs looks up a
dentry on one of the underlying layers, since search permission on base
directory was already checked in ovl_permission().

More specifically using lookup_one_len() causes a problem when the lower
directory lacks search permission for a specific user while the upper
directory does have search permission.  Since lookups are cached, this
causes inconsistency in behavior: success depends on who did the first
lookup.

So instead use lookup_hash() which doesn't do the permission check.

Reported-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-10 23:58:18 -04:00
Miklos Szeredi
3c9fe8cdff vfs: add lookup_hash() helper
Overlayfs needs lookup without inode_permission() and already has the name
hash (in form of dentry->d_name on overlayfs dentry).  It also doesn't
support filesystems with d_op->d_hash() so basically it only needs
the actual hashed lookup from lookup_one_len_unlocked()

So add a new helper that does unlocked lookup of a hashed name.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-10 23:56:28 -04:00
Miklos Szeredi
9409e22acd vfs: rename: check backing inode being equal
If a file is renamed to a hardlink of itself POSIX specifies that rename(2)
should do nothing and return success.

This condition is checked in vfs_rename().  However it won't detect hard
links on overlayfs where these are given separate inodes on the overlayfs
layer.

Overlayfs itself detects this condition and returns success without doing
anything, but then vfs_rename() will proceed as if this was a successful
rename (detach_mounts(), d_move()).

The correct thing to do is to detect this condition before even calling
into overlayfs.  This patch does this by calling vfs_select_inode() to get
the underlying inodes.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.2+
2016-05-10 23:55:43 -04:00
Miklos Szeredi
54d5ca871e vfs: add vfs_select_inode() helper
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.2+
2016-05-10 23:55:01 -04:00
Robin Humble
1e92a61c4c Revert "proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan""
This reverts the 4.6-rc1 commit 7e2bc81da3 ("proc/base: make prompt
shell start from new line after executing "cat /proc/$pid/wchan")
because it breaks /proc/$PID/whcan formatting in ps and top.

Revert also because the patch is inconsistent - it adds a newline at the
end of only the '0' wchan, and does not add a newline when
/proc/$PID/wchan contains a symbol name.

eg.
$ ps -eo pid,stat,wchan,comm
PID STAT WCHAN  COMMAND
...
1189 S    -      dbus-launch
1190 Ssl  0
dbus-daemon
1198 Sl   0
lightdm
1299 Ss   ep_pol systemd
1301 S    -      (sd-pam)
1304 Ss   wait   sh

Signed-off-by: Robin Humble <plaguedbypenguins@gmail.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-09 17:40:59 -07:00
Serge E. Hallyn
4f41fc5962 cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
Patch summary:

When showing a cgroupfs entry in mountinfo, show the path of the mount
root dentry relative to the reader's cgroup namespace root.

Short explanation (courtesy of mkerrisk):

If we create a new cgroup namespace, then we want both /proc/self/cgroup
and /proc/self/mountinfo to show cgroup paths that are correctly
virtualized with respect to the cgroup mount point.  Previous to this
patch, /proc/self/cgroup shows the right info, but /proc/self/mountinfo
does not.

Long version:

When a uid 0 task which is in freezer cgroup /a/b, unshares a new cgroup
namespace, and then mounts a new instance of the freezer cgroup, the new
mount will be rooted at /a/b.  The root dentry field of the mountinfo
entry will show '/a/b'.

 cat > /tmp/do1 << EOF
 mount -t cgroup -o freezer freezer /mnt
 grep freezer /proc/self/mountinfo
 EOF

 unshare -Gm  bash /tmp/do1
 > 330 160 0:34 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,freezer
 > 355 133 0:34 /a/b /mnt rw,relatime - cgroup freezer rw,freezer

The task's freezer cgroup entry in /proc/self/cgroup will simply show
'/':

 grep freezer /proc/self/cgroup
 9:freezer:/

If instead the same task simply bind mounts the /a/b cgroup directory,
the resulting mountinfo entry will again show /a/b for the dentry root.
However in this case the task will find its own cgroup at /mnt/a/b,
not at /mnt:

 mount --bind /sys/fs/cgroup/freezer/a/b /mnt
 130 25 0:34 /a/b /mnt rw,nosuid,nodev,noexec,relatime shared:21 - cgroup cgroup rw,freezer

In other words, there is no way for the task to know, based on what is
in mountinfo, which cgroup directory is its own.

Example (by mkerrisk):

First, a little script to save some typing and verbiage:

echo -e "\t/proc/self/cgroup:\t$(cat /proc/self/cgroup | grep freezer)"
cat /proc/self/mountinfo | grep freezer |
        awk '{print "\tmountinfo:\t\t" $4 "\t" $5}'

Create cgroup, place this shell into the cgroup, and look at the state
of the /proc files:

2653
2653                         # Our shell
14254                        # cat(1)
        /proc/self/cgroup:      10:freezer:/a/b
        mountinfo:              /       /sys/fs/cgroup/freezer

Create a shell in new cgroup and mount namespaces. The act of creating
a new cgroup namespace causes the process's current cgroups directories
to become its cgroup root directories. (Here, I'm using my own version
of the "unshare" utility, which takes the same options as the util-linux
version):

Look at the state of the /proc files:

        /proc/self/cgroup:      10:freezer:/
        mountinfo:              /       /sys/fs/cgroup/freezer

The third entry in /proc/self/cgroup (the pathname of the cgroup inside
the hierarchy) is correctly virtualized w.r.t. the cgroup namespace, which
is rooted at /a/b in the outer namespace.

However, the info in /proc/self/mountinfo is not for this cgroup
namespace, since we are seeing a duplicate of the mount from the
old mount namespace, and the info there does not correspond to the
new cgroup namespace. However, trying to create a new mount still
doesn't show us the right information in mountinfo:

                                      # propagating to other mountns
        /proc/self/cgroup:      7:freezer:/
        mountinfo:              /a/b    /mnt/freezer

The act of creating a new cgroup namespace caused the process's
current freezer directory, "/a/b", to become its cgroup freezer root
directory. In other words, the pathname directory of the directory
within the newly mounted cgroup filesystem should be "/",
but mountinfo wrongly shows us "/a/b". The consequence of this is
that the process in the cgroup namespace cannot correctly construct
the pathname of its cgroup root directory from the information in
/proc/PID/mountinfo.

With this patch, the dentry root field in mountinfo is shown relative
to the reader's cgroup namespace.  So the same steps as above:

        /proc/self/cgroup:      10:freezer:/a/b
        mountinfo:              /       /sys/fs/cgroup/freezer
        /proc/self/cgroup:      10:freezer:/
        mountinfo:              /../..  /sys/fs/cgroup/freezer
        /proc/self/cgroup:      10:freezer:/
        mountinfo:              /       /mnt/freezer

cgroup.clone_children  freezer.parent_freezing  freezer.state      tasks
cgroup.procs           freezer.self_freezing    notify_on_release
3164
2653                   # First shell that placed in this cgroup
3164                   # Shell started by 'unshare'
14197                  # cat(1)

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Tested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-09 12:15:03 -04:00
Al Viro
99d825822e get_rock_ridge_filename(): handle malformed NM entries
Payloads of NM entries are not supposed to contain NUL.  When we run
into such, only the part prior to the first NUL goes into the
concatenation (i.e. the directory entry name being encoded by a bunch
of NM entries).  We do stop when the amount collected so far + the
claimed amount in the current NM entry exceed 254.  So far, so good,
but what we return as the total length is the sum of *claimed*
sizes, not the actual amount collected.  And that can grow pretty
large - not unlimited, since you'd need to put CE entries in
between to be able to get more than the maximum that could be
contained in one isofs directory entry / continuation chunk and
we are stop once we'd encountered 32 CEs, but you can get about 8Kb
easily.  And that's what will be passed to readdir callback as the
name length.  8Kb __copy_to_user() from a buffer allocated by
__get_free_page()

Cc: stable@vger.kernel.org # 0.98pl6+ (yes, really)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-07 22:52:39 -04:00
Mathias Krause
8148a73c99 proc: prevent accessing /proc/<PID>/environ until it's ready
If /proc/<PID>/environ gets read before the envp[] array is fully set up
in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to
read more bytes than are actually written, as env_start will already be
set but env_end will still be zero, making the range calculation
underflow, allowing to read beyond the end of what has been written.

Fix this as it is done for /proc/<PID>/cmdline by testing env_end for
zero.  It is, apparently, intentionally set last in create_*_tables().

This bug was found by the PaX size_overflow plugin that detected the
arithmetic underflow of 'this_len = env_end - (env_start + src)' when
env_end is still zero.

The expected consequence is that userland trying to access
/proc/<PID>/environ of a not yet fully set up process may get
inconsistent data as we're in the middle of copying in the environment
variables.

Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Pax Team <pageexec@freemail.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-05 17:38:53 -07:00
Linus Torvalds
c5e0666c5a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull userns fix from Eric Biederman:
 "This contains just a single fix for a nasty oops"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  propogate_mnt: Handle the first propogated copy being a slave
2016-05-05 08:41:57 -07:00
Eric W. Biederman
5ec0811d30 propogate_mnt: Handle the first propogated copy being a slave
When the first propgated copy was a slave the following oops would result:
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
> IP: [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
> PGD bacd4067 PUD bac66067 PMD 0
> Oops: 0000 [#1] SMP
> Modules linked in:
> CPU: 1 PID: 824 Comm: mount Not tainted 4.6.0-rc5userns+ #1523
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
> task: ffff8800bb0a8000 ti: ffff8800bac3c000 task.ti: ffff8800bac3c000
> RIP: 0010:[<ffffffff811fba4e>]  [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
> RSP: 0018:ffff8800bac3fd38  EFLAGS: 00010283
> RAX: 0000000000000000 RBX: ffff8800bb77ec00 RCX: 0000000000000010
> RDX: 0000000000000000 RSI: ffff8800bb58c000 RDI: ffff8800bb58c480
> RBP: ffff8800bac3fd48 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000001ca1 R11: 0000000000001c9d R12: 0000000000000000
> R13: ffff8800ba713800 R14: ffff8800bac3fda0 R15: ffff8800bb77ec00
> FS:  00007f3c0cd9b7e0(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000010 CR3: 00000000bb79d000 CR4: 00000000000006e0
> Stack:
>  ffff8800bb77ec00 0000000000000000 ffff8800bac3fd88 ffffffff811fbf85
>  ffff8800bac3fd98 ffff8800bb77f080 ffff8800ba713800 ffff8800bb262b40
>  0000000000000000 0000000000000000 ffff8800bac3fdd8 ffffffff811f1da0
> Call Trace:
>  [<ffffffff811fbf85>] propagate_mnt+0x105/0x140
>  [<ffffffff811f1da0>] attach_recursive_mnt+0x120/0x1e0
>  [<ffffffff811f1ec3>] graft_tree+0x63/0x70
>  [<ffffffff811f1f6b>] do_add_mount+0x9b/0x100
>  [<ffffffff811f2c1a>] do_mount+0x2aa/0xdf0
>  [<ffffffff8117efbe>] ? strndup_user+0x4e/0x70
>  [<ffffffff811f3a45>] SyS_mount+0x75/0xc0
>  [<ffffffff8100242b>] do_syscall_64+0x4b/0xa0
>  [<ffffffff81988f3c>] entry_SYSCALL64_slow_path+0x25/0x25
> Code: 00 00 75 ec 48 89 0d 02 22 22 01 8b 89 10 01 00 00 48 89 05 fd 21 22 01 39 8e 10 01 00 00 0f 84 e0 00 00 00 48 8b 80 d8 00 00 00 <48> 8b 50 10 48 89 05 df 21 22 01 48 89 15 d0 21 22 01 8b 53 30
> RIP  [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
>  RSP <ffff8800bac3fd38>
> CR2: 0000000000000010
> ---[ end trace 2725ecd95164f217 ]---

This oops happens with the namespace_sem held and can be triggered by
non-root users.  An all around not pleasant experience.

To avoid this scenario when finding the appropriate source mount to
copy stop the walk up the mnt_master chain when the first source mount
is encountered.

Further rewrite the walk up the last_source mnt_master chain so that
it is clear what is going on.

The reason why the first source mount is special is that it it's
mnt_parent is not a mount in the dest_mnt propagation tree, and as
such termination conditions based up on the dest_mnt mount propgation
tree do not make sense.

To avoid other kinds of confusion last_dest is not changed when
computing last_source.  last_dest is only used once in propagate_one
and that is above the point of the code being modified, so changing
the global variable is meaningless and confusing.

Cc: stable@vger.kernel.org
fixes: f2ebb3a921 ("smarter propagate_mnt()")
Reported-by: Tycho Andersen <tycho.andersen@canonical.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-05-05 09:54:45 -05:00
Al Viro
6a480a7842 ecryptfs: fix handling of directory opening
First of all, trying to open them r/w is idiocy; it's guaranteed to fail.
Moreover, assigning ->f_pos and assuming that everything will work is
blatantly broken - try that with e.g. tmpfs as underlying layer and watch
the fireworks.  There may be a non-trivial amount of state associated with
current IO position, well beyond the numeric offset.  Using the single
struct file associated with underlying inode is really not a good idea;
we ought to open one for each ecryptfs directory struct file.

Additionally, file_operations both for directories and non-directories are
full of pointless methods; non-directories should *not* have ->iterate(),
directories should not have ->flush(), ->fasync() and ->splice_read().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-04 14:04:13 -04:00
Linus Torvalds
610603a520 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse fixes from Miklos Szeredi:
 "Fix a regression and update the MAINTAINERS entry for fuse"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: update mailing list in MAINTAINERS
  fuse: Fix return value from fuse_get_user_pages()
2016-05-03 14:23:58 -07:00
Linus Torvalds
33656a1f2e Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull UDF fix from Jan Kara:
 "A fix of a regression in UDF that got introduced in 4.6-rc1 by one of
  the charset encoding fixes"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Fix conversion of 'dstring' fields to UTF8
2016-05-02 09:59:57 -07:00
Serge Hallyn
e99ed4de17 kernfs_path_from_node_locked: don't overwrite nlen
We've calculated @len to be the bytes we need for '/..' entries from
@kn_from to the common ancestor, and calculated @nlen to be the extra
bytes we need to get from the common ancestor to @kn_to.  We use them
as such at the end.  But in the loop copying the actual entries, we
overwrite @nlen.  Use a temporary variable for that instead.

Without this, the return length, when the buffer is large enough, is
wrong.  (When the buffer is NULL or too small, the returned value is
correct. The buffer contents are also correct.)

Interestingly, no callers of this function are affected by this as of
yet.  However the upcoming cgroup_show_path() will be.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2016-05-02 12:36:00 -04:00
Al Viro
10c64cea04 atomic_open(): fix the handling of create_error
* if we have a hashed negative dentry and either CREAT|EXCL on
r/o filesystem, or CREAT|TRUNC on r/o filesystem, or CREAT|EXCL
with failing may_o_create(), we should fail with EROFS or the
error may_o_create() has returned, but not ENOENT.  Which is what
the current code ends up returning.

* if we have CREAT|TRUNC hitting a regular file on a read-only
filesystem, we can't fail with EROFS here.  At the very least,
not until we'd done follow_managed() - we might have a writable
file (or a device, for that matter) bound on top of that one.
Moreover, the code downstream will see that O_TRUNC and attempt
to grab the write access (*after* following possible mount), so
if we really should fail with EROFS, it will happen.  No need
to do that inside atomic_open().

The real logics is much simpler than what the current code is
trying to do - if we decided to go for simple lookup, ended
up with a negative dentry *and* had create_error set, fail with
create_error.  No matter whether we'd got that negative dentry
from lookup_real() or had found it in dcache.

Cc: stable@vger.kernel.org # v3.6+
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-30 16:40:52 -04:00
Linus Torvalds
1d003af2ef Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "20 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  Documentation/sysctl/vm.txt: update numa_zonelist_order description
  lib/stackdepot.c: allow the stack trace hash to be zero
  rapidio: fix potential NULL pointer dereference
  mm/memory-failure: fix race with compound page split/merge
  ocfs2/dlm: return zero if deref_done message is successfully handled
  Ananth has moved
  kcov: don't profile branches in kcov
  kcov: don't trace the code coverage code
  mm: wake kcompactd before kswapd's short sleep
  .mailmap: add Frank Rowand
  mm/hwpoison: fix wrong num_poisoned_pages accounting
  mm: call swap_slot_free_notify() with page lock held
  mm: vmscan: reclaim highmem zone if buffer_heads is over limit
  numa: fix /proc/<pid>/numa_maps for THP
  mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
  mailmap: fix Krzysztof Kozlowski's misspelled name
  thp: keep huge zero page pinned until tlb flush
  mm: exclude HugeTLB pages from THP page_mapped() logic
  kexec: export OFFSET(page.compound_head) to find out compound tail page
  kexec: update VMCOREINFO for compound_order/dtor
2016-04-29 11:21:22 -07:00
xuejiufei
b73413647e ocfs2/dlm: return zero if deref_done message is successfully handled
dlm_deref_lockres_done_handler() should return zero if the message is
successfully handled.

Fixes: 60d663cb52 ("ocfs2/dlm: add DEREF_DONE message").
Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
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>
2016-04-28 19:34:04 -07:00
Gerald Schaefer
28093f9f34 numa: fix /proc/<pid>/numa_maps for THP
In gather_pte_stats() a THP pmd is cast into a pte, which is wrong
because the layouts may differ depending on the architecture.  On s390
this will lead to inaccurate numa_maps accounting in /proc because of
misguided pte_present() and pte_dirty() checks on the fake pte.

On other architectures pte_present() and pte_dirty() may work by chance,
but there may be an issue with direct-access (dax) mappings w/o
underlying struct pages when HAVE_PTE_SPECIAL is set and THP is
available.  In vm_normal_page() the fake pte will be checked with
pte_special() and because there is no "special" bit in a pmd, this will
always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be
skipped.  On dax mappings w/o struct pages, an invalid struct page
pointer would then be returned that can crash the kernel.

This patch fixes the numa_maps THP handling by introducing new "_pmd"
variants of the can_gather_numa_stats() and vm_normal_page() functions.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>	[4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
Linus Torvalds
6fa9bffbcc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph fixes from Sage Weil:
 "There is a lifecycle fix in the auth code, a fix for a narrow race
  condition on map, and a helpful message in the log when there is a
  feature mismatch (which happens frequently now that the default
  server-side options have changed)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: report unsupported features to syslog
  rbd: fix rbd map vs notify races
  libceph: make authorizer destruction independent of ceph_auth_client
2016-04-28 18:59:24 -07:00
Linus Torvalds
8ead9dd547 devpts: more pty driver interface cleanups
This is more prep-work for the upcoming pty changes.  Still just code
cleanup with no actual semantic changes.

This removes a bunch pointless complexity by just having the slave pty
side remember the dentry associated with the devpts slave rather than
the inode.  That allows us to remove all the "look up the dentry" code
for when we want to remove it again.

Together with moving the tty pointer from "inode->i_private" to
"dentry->d_fsdata" and getting rid of pointless inode locking, this
removes about 30 lines of code.  Not only is the end result smaller,
it's simpler and easier to understand.

The old code, for example, depended on the d_find_alias() to not just
find the dentry, but also to check that it is still hashed, which in
turn validated the tty pointer in the inode.

That is a _very_ roundabout way to say "invalidate the cached tty
pointer when the dentry is removed".

The new code just does

	dentry->d_fsdata = NULL;

in devpts_pty_kill() instead, invalidating the tty pointer rather more
directly and obviously.  Don't do something complex and subtle when the
obvious straightforward approach will do.

The rest of the patch (ie apart from code deletion and the above tty
pointer clearing) is just switching the calling convention to pass the
dentry or file pointer around instead of the inode.

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Greg KH <greg@kroah.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-26 15:47:32 -07:00
Ilya Dryomov
6c1ea260f8 libceph: make authorizer destruction independent of ceph_auth_client
Starting the kernel client with cephx disabled and then enabling cephx
and restarting userspace daemons can result in a crash:

    [262671.478162] BUG: unable to handle kernel paging request at ffffebe000000000
    [262671.531460] IP: [<ffffffff811cd04a>] kfree+0x5a/0x130
    [262671.584334] PGD 0
    [262671.635847] Oops: 0000 [#1] SMP
    [262672.055841] CPU: 22 PID: 2961272 Comm: kworker/22:2 Not tainted 4.2.0-34-generic #39~14.04.1-Ubuntu
    [262672.162338] Hardware name: Dell Inc. PowerEdge R720/068CDY, BIOS 2.4.3 07/09/2014
    [262672.268937] Workqueue: ceph-msgr con_work [libceph]
    [262672.322290] task: ffff88081c2d0dc0 ti: ffff880149ae8000 task.ti: ffff880149ae8000
    [262672.428330] RIP: 0010:[<ffffffff811cd04a>]  [<ffffffff811cd04a>] kfree+0x5a/0x130
    [262672.535880] RSP: 0018:ffff880149aeba58  EFLAGS: 00010286
    [262672.589486] RAX: 000001e000000000 RBX: 0000000000000012 RCX: ffff8807e7461018
    [262672.695980] RDX: 000077ff80000000 RSI: ffff88081af2be04 RDI: 0000000000000012
    [262672.803668] RBP: ffff880149aeba78 R08: 0000000000000000 R09: 0000000000000000
    [262672.912299] R10: ffffebe000000000 R11: ffff880819a60e78 R12: ffff8800aec8df40
    [262673.021769] R13: ffffffffc035f70f R14: ffff8807e5b138e0 R15: ffff880da9785840
    [262673.131722] FS:  0000000000000000(0000) GS:ffff88081fac0000(0000) knlGS:0000000000000000
    [262673.245377] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [262673.303281] CR2: ffffebe000000000 CR3: 0000000001c0d000 CR4: 00000000001406e0
    [262673.417556] Stack:
    [262673.472943]  ffff880149aeba88 ffff88081af2be04 ffff8800aec8df40 ffff88081af2be04
    [262673.583767]  ffff880149aeba98 ffffffffc035f70f ffff880149aebac8 ffff8800aec8df00
    [262673.694546]  ffff880149aebac8 ffffffffc035c89e ffff8807e5b138e0 ffff8805b047f800
    [262673.805230] Call Trace:
    [262673.859116]  [<ffffffffc035f70f>] ceph_x_destroy_authorizer+0x1f/0x50 [libceph]
    [262673.968705]  [<ffffffffc035c89e>] ceph_auth_destroy_authorizer+0x3e/0x60 [libceph]
    [262674.078852]  [<ffffffffc0352805>] put_osd+0x45/0x80 [libceph]
    [262674.134249]  [<ffffffffc035290e>] remove_osd+0xae/0x140 [libceph]
    [262674.189124]  [<ffffffffc0352aa3>] __reset_osd+0x103/0x150 [libceph]
    [262674.243749]  [<ffffffffc0354703>] kick_requests+0x223/0x460 [libceph]
    [262674.297485]  [<ffffffffc03559e2>] ceph_osdc_handle_map+0x282/0x5e0 [libceph]
    [262674.350813]  [<ffffffffc035022e>] dispatch+0x4e/0x720 [libceph]
    [262674.403312]  [<ffffffffc034bd91>] try_read+0x3d1/0x1090 [libceph]
    [262674.454712]  [<ffffffff810ab7c2>] ? dequeue_entity+0x152/0x690
    [262674.505096]  [<ffffffffc034cb1b>] con_work+0xcb/0x1300 [libceph]
    [262674.555104]  [<ffffffff8108fb3e>] process_one_work+0x14e/0x3d0
    [262674.604072]  [<ffffffff810901ea>] worker_thread+0x11a/0x470
    [262674.652187]  [<ffffffff810900d0>] ? rescuer_thread+0x310/0x310
    [262674.699022]  [<ffffffff810957a2>] kthread+0xd2/0xf0
    [262674.744494]  [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0
    [262674.789543]  [<ffffffff817bd81f>] ret_from_fork+0x3f/0x70
    [262674.834094]  [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0

What happens is the following:

    (1) new MON session is established
    (2) old "none" ac is destroyed
    (3) new "cephx" ac is constructed
    ...
    (4) old OSD session (w/ "none" authorizer) is put
          ceph_auth_destroy_authorizer(ac, osd->o_auth.authorizer)

osd->o_auth.authorizer in the "none" case is just a bare pointer into
ac, which contains a single static copy for all services.  By the time
we get to (4), "none" ac, freed in (2), is long gone.  On top of that,
a new vtable installed in (3) points us at ceph_x_destroy_authorizer(),
so we end up trying to destroy a "none" authorizer with a "cephx"
destructor operating on invalid memory!

To fix this, decouple authorizer destruction from ac and do away with
a single static "none" authorizer by making a copy for each OSD or MDS
session.  Authorizers themselves are independent of ac and so there is
no reason for destroy_authorizer() to be an ac op.  Make it an op on
the authorizer itself by turning ceph_authorizer into a real struct.

Fixes: http://tracker.ceph.com/issues/15447

Reported-by: Alan Zhang <alan.zhang@linux.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2016-04-25 20:54:13 +02:00
Andrew Gabbasov
c26f6c6157 udf: Fix conversion of 'dstring' fields to UTF8
Commit 9293fcfbc1
("udf: Remove struct ustr as non-needed intermediate storage"),
while getting rid of 'struct ustr', does not take any special care
of 'dstring' fields and effectively use fixed field length instead
of actual string length, encoded in the last byte of the field.

Also, commit 484a10f493
("udf: Merge linux specific translation into CS0 conversion function")
introduced checking of the length of the string being converted,
requiring proper alignment to number of bytes constituing each
character.

The UDF volume identifier is represented as a 32-bytes 'dstring',
and needs to be converted from CS0 to UTF8, while mounting UDF
filesystem. The changes in mentioned commits can in some cases
lead to incorrect handling of volume identifier:
- if the actual string in 'dstring' is of maximal length and
does not have zero bytes separating it from dstring encoded
length in last byte, that last byte may be included in conversion,
thus making incorrect resulting string;
- if the identifier is encoded with 2-bytes characters (compression
code is 16), the length of 31 bytes (32 bytes of field length minus
1 byte of compression code), taken as the string length, is reported
as an incorrect (unaligned) length, and the conversion fails, which
in its turn leads to volume mounting failure.

This patch introduces handling of 'dstring' encoded length field
in udf_CS0toUTF8 function, that is used in all and only cases
when 'dstring' fields are converted. Currently these cases are
processing of Volume Identifier and Volume Set Identifier fields.
The function is also renamed to udf_dstrCS0toUTF8 to distinctly
indicate that it handles 'dstring' input.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2016-04-25 15:18:50 +02:00
Ashish Samant
2c932d4c91 fuse: Fix return value from fuse_get_user_pages()
fuse_get_user_pages() should return error or 0. Otherwise fuse_direct_io
read will not return 0 to indicate that read has completed.

Fixes: 742f992708 ("fuse: return patrial success from fuse_direct_io()")
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-04-25 13:01:04 +02:00
Linus Torvalds
9a0e3eea25 Merge branch 'ptmx-cleanup'
Merge the ptmx internal interface cleanup branch.

This doesn't change semantics, but it should be a sane basis for
eventually getting the multi-instance devpts code into some sane shape
where we can get rid of the kernel config option.  Which we can
hopefully get done next merge window..

* ptmx-cleanup:
  devpts: clean up interface to pty drivers
2016-04-19 16:36:18 -07:00
Linus Torvalds
67245ff332 devpts: clean up interface to pty drivers
This gets rid of the horrible notion of having that

    struct inode *ptmx_inode

be the linchpin of the interface between the pty code and devpts.

By de-emphasizing the ptmx inode, a lot of things actually get cleaner,
and we will have a much saner way forward.  In particular, this will
allow us to associate with any particular devpts instance at open-time,
and not be artificially tied to one particular ptmx inode.

The patch itself is actually fairly straightforward, and apart from some
locking and return path cleanups it's pretty mechanical:

 - the interfaces that devpts exposes all take "struct pts_fs_info *"
   instead of "struct inode *ptmx_inode" now.

   NOTE! The "struct pts_fs_info" thing is a completely opaque structure
   as far as the pty driver is concerned: it's still declared entirely
   internally to devpts. So the pty code can't actually access it in any
   way, just pass it as a "cookie" to the devpts code.

 - the "look up the pts fs info" is now a single clear operation, that
   also does the reference count increment on the pts superblock.

   So "devpts_add/del_ref()" is gone, and replaced by a "lookup and get
   ref" operation (devpts_get_ref(inode)), along with a "put ref" op
   (devpts_put_ref()).

 - the pty master "tty->driver_data" field now contains the pts_fs_info,
   not the ptmx inode.

 - because we don't care about the ptmx inode any more as some kind of
   base index, the ref counting can now drop the inode games - it just
   gets the ref on the superblock.

 - the pts_fs_info now has a back-pointer to the super_block. That's so
   that we can easily look up the information we actually need. Although
   quite often, the pts fs info was actually all we wanted, and not having
   to look it up based on some magical inode makes things more
   straightforward.

In particular, now that "devpts_get_ref(inode)" operation should really
be the *only* place we need to look up what devpts instance we're
associated with, and we do it exactly once, at ptmx_open() time.

The other side of this is that one ptmx node could now be associated
with multiple different devpts instances - you could have a single
/dev/ptmx node, and then have multiple mount namespaces with their own
instances of devpts mounted on /dev/pts/.  And that's all perfectly sane
in a model where we just look up the pts instance at open time.

This will eventually allow us to get rid of our odd single-vs-multiple
pts instance model, but this patch in itself changes no semantics, only
an internal binding model.

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Greg KH <greg@kroah.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-18 13:43:02 -07:00
Linus Torvalds
e1e22b27ec "driver core" fixes for 4.6-rc4
Here are 3 small fixes 4.6-rc4.  Two fix up some lz4 issues with big
 endian systems, and the remaining one resolves a minor debugfs issue
 that was reported.
 
 All have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull misc fixes from Greg KH:
 "Here are three small fixes for 4.6-rc4.

  Two fix up some lz4 issues with big endian systems, and the remaining
  one resolves a minor debugfs issue that was reported.

  All have been in linux-next with no reported issues"

* tag 'driver-core-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lib: lz4: cleanup unaligned access efficiency detection
  lib: lz4: fixed zram with lz4 on big endian machines
  debugfs: Make automount point inodes permanently empty
2016-04-16 20:53:50 -07:00
Linus Torvalds
dfe70581c1 for-linus-4.6-rc4
These patches fix f2fs and fscrypto based on -rc3 bug fixes in ext4 crypto,
 which have not yet been fully propagated as follows.
  - use of dget_parent and file_dentry to avoid crashes
  - disallow RCU-mode lookup in d_invalidate
  - disallow -ENOMEM in the core data encryption path
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Merge tag 'for-linus-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs/fscrypto fixes from Jaegeuk Kim:
 "In addition to f2fs/fscrypto fixes, I've added one patch which
  prevents RCU mode lookup in d_revalidate, as Al mentioned.

  These patches fix f2fs and fscrypto based on -rc3 bug fixes in ext4
  crypto, which have not yet been fully propagated as follows.

   - use of dget_parent and file_dentry to avoid crashes
   - disallow RCU-mode lookup in d_invalidate
   - disallow -ENOMEM in the core data encryption path"

* tag 'for-linus-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
  ext4/fscrypto: avoid RCU lookup in d_revalidate
  fscrypto: don't let data integrity writebacks fail with ENOMEM
  f2fs: use dget_parent and file_dentry in f2fs_file_open
  fscrypto: use dget_parent() in fscrypt_d_revalidate()
2016-04-14 18:22:42 -07:00
Linus Torvalds
34dbbcdbf6 Make file credentials available to the seqfile interfaces
A lot of seqfile users seem to be using things like %pK that uses the
credentials of the current process, but that is actually completely
wrong for filesystem interfaces.

The unix semantics for permission checking files is to check permissions
at _open_ time, not at read or write time, and that is not just a small
detail: passing off stdin/stdout/stderr to a suid application and making
the actual IO happen in privileged context is a classic exploit
technique.

So if we want to be able to look at permissions at read time, we need to
use the file open credentials, not the current ones.  Normal file
accesses can just use "f_cred" (or any of the helper functions that do
that, like file_ns_capable()), but the seqfile interfaces do not have
any such options.

It turns out that seq_file _does_ save away the user_ns information of
the file, though.  Since user_ns is just part of the full credential
information, replace that special case with saving off the cred pointer
instead, and suddenly seq_file has all the permission information it
needs.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-14 12:56:09 -07:00
Jaegeuk Kim
03a8bb0e53 ext4/fscrypto: avoid RCU lookup in d_revalidate
As Al pointed, d_revalidate should return RCU lookup before using d_inode.
This was originally introduced by:
commit 34286d6662 ("fs: rcu-walk aware d_revalidate method").

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: stable <stable@vger.kernel.org>
2016-04-12 20:01:35 -07:00
Seth Forshee
87243deb88 debugfs: Make automount point inodes permanently empty
Starting with 4.1 the tracing subsystem has its own filesystem
which is automounted in the tracing subdirectory of debugfs.
Prior to this debugfs could be bind mounted in a cloned mount
namespace, but if tracefs has been mounted under debugfs this
now fails because there is a locked child mount. This creates
a regression for container software which bind mounts debugfs
to satisfy the assumption of some userspace software.

In other pseudo filesystems such as proc and sysfs we're already
creating mountpoints like this in such a way that no dirents can
be created in the directories, allowing them to be exceptions to
some MNT_LOCKED tests. In fact we're already do this for the
tracefs mountpoint in sysfs.

Do the same in debugfs_create_automount(), since the intention
here is clearly to create a mountpoint. This fixes the regression,
as locked child mounts on permanently empty directories do not
cause a bind mount to fail.

Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12 15:01:53 -07:00
Jaegeuk Kim
b32e4482aa fscrypto: don't let data integrity writebacks fail with ENOMEM
This patch fixes the issue introduced by the ext4 crypto fix in a same manner.
For F2FS, however, we flush the pending IOs and wait for a while to acquire free
memory.

Fixes: c9af28fdd4 ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM")
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12 10:25:30 -07:00
Jaegeuk Kim
33b1395124 f2fs: use dget_parent and file_dentry in f2fs_file_open
This patch synced with the below two ext4 crypto fixes together.

In 4.6-rc1, f2fs newly introduced accessing f_path.dentry which crashes
overlayfs. To fix, now we need to use file_dentry() to access that field.

Fixes: c0a37d4878 ("ext4: use file_dentry()")
Fixes: 9dd78d8c9a ("ext4: use dget_parent() in ext4_file_open()")
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12 10:24:22 -07:00
Jaegeuk Kim
d7d7535289 fscrypto: use dget_parent() in fscrypt_d_revalidate()
This patch updates fscrypto along with the below ext4 crypto change.

Fixes: 3d43bcfef5 ("ext4 crypto: use dget_parent() in ext4_d_revalidate()")
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12 10:24:04 -07:00
Linus Torvalds
9f2394c9be Revert "ext4: allow readdir()'s of large empty directories to be interrupted"
This reverts commit 1028b55baf.

It's broken: it makes ext4 return an error at an invalid point, causing
the readdir wrappers to write the the position of the last successful
directory entry into the position field, which means that the next
readdir will now return that last successful entry _again_.

You can only return fatal errors (that terminate the readdir directory
walk) from within the filesystem readdir functions, the "normal" errors
(that happen when the readdir buffer fills up, for example) happen in
the iterorator where we know the position of the actual failing entry.

I do have a very different patch that does the "signal_pending()"
handling inside the iterator function where it is allowable, but while
that one passes all the sanity checks, I screwed up something like four
times while emailing it out, so I'm not going to commit it today.

So my track record is not good enough, and the stars will have to align
better before that one gets committed.  And it would be good to get some
review too, of course, since celestial alignments are always an iffy
debugging model.

IOW, let's just revert the commit that caused the problem for now.

Reported-by: Greg Thelen <gthelen@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-10 16:52:24 -07:00
Linus Torvalds
839a3f7657 Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "These are bug fixes, including a really old fsync bug, and a few trace
  points to help us track down problems in the quota code"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix file/data loss caused by fsync after rename and new inode
  btrfs: Reset IO error counters before start of device replacing
  btrfs: Add qgroup tracing
  Btrfs: don't use src fd for printk
  btrfs: fallback to vmalloc in btrfs_compare_tree
  btrfs: handle non-fatal errors in btrfs_qgroup_inherit()
  btrfs: Output more info for enospc_debug mount option
  Btrfs: fix invalid reference in replace_path
  Btrfs: Improve FL_KEEP_SIZE handling in fallocate
2016-04-09 10:41:34 -07:00
Linus Torvalds
6759212640 Orangefs: cleanups and a strncpy vulnerability fix.
Cleanups:
 
   - remove an unused variable from orangefs_readdir.
   - clean up printk wrapper used for ofs "gossip" debugging.
   - clean up truncate ctime and mtime setting in inode.c
   - remove a useless null check found by coccinelle.
   - optimize some memcpy/memset boilerplate code.
   - remove some useless sanity checks from xattr.c
 
 Fix:
 
   - fix a potential strncpy vulnerability.
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Merge tag 'for-linus-4.6-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux

Pull orangefs fixes from Mike Marshall:
 "Orangefs cleanups and a strncpy vulnerability fix.

  Cleanups:
   - remove an unused variable from orangefs_readdir.
   - clean up printk wrapper used for ofs "gossip" debugging.
   - clean up truncate ctime and mtime setting in inode.c
   - remove a useless null check found by coccinelle.
   - optimize some memcpy/memset boilerplate code.
   - remove some useless sanity checks from xattr.c

  Fix:
   - fix a potential strncpy vulnerability"

* tag 'for-linus-4.6-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: remove unused variable
  orangefs: Add KERN_<LEVEL> to gossip_<level> macros
  orangefs: strncpy -> strscpy
  orangefs: clean up truncate ctime and mtime setting
  Orangefs: fix ifnullfree.cocci warnings
  Orangefs: optimize boilerplate code.
  Orangefs: xattr.c cleanup
2016-04-09 10:33:58 -07:00
Martin Brandenburg
e56f498142 orangefs: remove unused variable
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 15:50:44 -04:00
Joe Perches
1917a69328 orangefs: Add KERN_<LEVEL> to gossip_<level> macros
Emit the logging messages at the appropriate levels.

Miscellanea:

o Change format to fmt
o Use the more common ##__VA_ARGS__

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 14:10:45 -04:00
Martin Brandenburg
2eacea74cc orangefs: strncpy -> strscpy
It would have been possible for a rogue client-core to send in a symlink
target which is not NUL terminated. This returns EIO if the client-core
gives us corrupt data.

Leave debugfs and superblock code as is for now.

Other dcache.c and namei.c strncpy instances are safe because
ORANGEFS_NAME_MAX = NAME_MAX + 1; there is always enough space for a
name plus a NUL byte.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 14:10:34 -04:00
Martin Brandenburg
f83140c146 orangefs: clean up truncate ctime and mtime setting
The ctime and mtime are always updated on a successful ftruncate and
only updated on a successful truncate where the size changed.

We handle the ``if the size changed'' bit.

This matches FUSE's behavior.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 14:10:31 -04:00
kbuild test robot
2fa37fd713 Orangefs: fix ifnullfree.cocci warnings
fs/orangefs/orangefs-debugfs.c:130:2-26: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values.

 NULL check before some freeing functions is not needed.

 Based on checkpatch warning
 "kfree(NULL) is safe this check is probably not required"
 and kfreeaddr.cocci by Julia Lawall.

Generated by: scripts/coccinelle/free/ifnullfree.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 14:08:38 -04:00
Mike Marshall
a9bb3ba81f Orangefs: optimize boilerplate code.
Suggested by David Binderman <dcb314@hotmail.com>
The former can potentially be a performance win over the latter.

memcpy(d, s, len);
memset(d+len, c, size-len);

memset(d, c, size);
memcpy(d, s, len);

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08 14:08:27 -04:00