linux-toradex.git/fs/ceph/super.c, branch v3.10.41

ceph: avoid accessing invalid memory

2014-01-09T20:24:25+00:00

commit 5446429630257f4723829409337a26c076907d5d upstream.

when mounting ceph with a dev name that starts with a slash, ceph
would attempt to access the character before that slash. Since we
don't actually own that byte of memory, we would trigger an
invalid access:

[   43.499934] BUG: unable to handle kernel paging request at ffff880fa3a97fff
[   43.500984] IP: [] parse_mount_options+0x1a4/0x300
[   43.501491] PGD 743b067 PUD 10283c4067 PMD 10282a6067 PTE 8000000fa3a97060
[   43.502301] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[   43.503006] Dumping ftrace buffer:
[   43.503596]    (ftrace buffer empty)
[   43.504046] CPU: 0 PID: 10879 Comm: mount Tainted: G        W    3.10.0-sasha #1129
[   43.504851] task: ffff880fa625b000 ti: ffff880fa3412000 task.ti: ffff880fa3412000
[   43.505608] RIP: 0010:[]  [] parse_mount_options$
[   43.506552] RSP: 0018:ffff880fa3413d08  EFLAGS: 00010286
[   43.507133] RAX: ffff880fa3a98000 RBX: ffff880fa3a98000 RCX: 0000000000000000
[   43.507893] RDX: ffff880fa3a98001 RSI: 000000000000002f RDI: ffff880fa3a98000
[   43.508610] RBP: ffff880fa3413d58 R08: 0000000000001f99 R09: ffff880fa3fe64c0
[   43.509426] R10: ffff880fa3413d98 R11: ffff880fa38710d8 R12: ffff880fa3413da0
[   43.509792] R13: ffff880fa3a97fff R14: 0000000000000000 R15: ffff880fa3413d90
[   43.509792] FS:  00007fa9c48757e0(0000) GS:ffff880fd2600000(0000) knlGS:000000000000$
[   43.509792] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   43.509792] CR2: ffff880fa3a97fff CR3: 0000000fa3bb9000 CR4: 00000000000006b0
[   43.509792] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   43.509792] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   43.509792] Stack:
[   43.509792]  0000e5180000000e ffffffff85ca1900 ffff880fa38710d8 ffff880fa3413d98
[   43.509792]  0000000000000120 0000000000000000 ffff880fa3a98000 0000000000000000
[   43.509792]  ffffffff85cf32a0 0000000000000000 ffff880fa3413dc8 ffffffff818f3c72
[   43.509792] Call Trace:
[   43.509792]  [] ceph_mount+0xa2/0x390
[   43.509792]  [] ? pcpu_alloc+0x334/0x3c0
[   43.509792]  [] mount_fs+0x8d/0x1a0
[   43.509792]  [] ? __alloc_percpu+0x10/0x20
[   43.509792]  [] vfs_kern_mount+0x79/0x100
[   43.509792]  [] do_new_mount+0xcd/0x1c0
[   43.509792]  [] do_mount+0x15d/0x210
[   43.509792]  [] ? strndup_user+0x45/0x60
[   43.509792]  [] SyS_mount+0x9d/0xe0
[   43.509792]  [] tracesys+0xdd/0xe2
[   43.509792] Code: 4c 8b 5d c0 74 0a 48 8d 50 01 49 89 14 24 eb 17 31 c0 48 83 c9 ff $
[   43.509792] RIP  [] parse_mount_options+0x1a4/0x300
[   43.509792]  RSP 
[   43.509792] CR2: ffff880fa3a97fff
[   43.509792] ---[ end trace 22469cd81e93af51 ]---

Signed-off-by: Sasha Levin 
Reviewed-by: Sage Weil 
Signed-off-by: Greg Kroah-Hartman

ceph: set up page array mempool with correct size

2013-05-02T04:17:50+00:00

In create_fs_client() a memory pool is set up be used for arrays of
pages that might be needed in ceph_writepages_start() if memory is
tight.  There are two problems with the way it's initialized:
    - The size provided is the number of pages we want in the
      array, but it should be the number of bytes required for
      that many page pointers.
    - The number of pages computed can end up being 0, while we
      will always need at least one page.

This patch fixes both of these problems.

This resolves the two simple problems defined in:
    http://tracker.ceph.com/issues/4603

Signed-off-by: Alex Elder 
Reviewed-by: Josh Durgin

fs: Limit sys_mount to only request filesystem modules.

2013-03-04T03:36:31+00:00

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn 
Acked-by: Kees Cook 
Reported-by: Kees Cook 
Signed-off-by: "Eric W. Biederman"

ceph: fix statvfs fr_size

2013-02-22T23:31:00+00:00

Different versions of glibc are broken in different ways, but the short of
it is that for the time being, frsize should == bsize, and be used as the
multiple for the blocks, free, and available fields.  This mirrors what is
done for NFS.  The previous reporting of the page size for frsize meant
that newer glibc and df would report a very small value for the fs size.

Fixes http://tracker.ceph.com/issues/3793.

Signed-off-by: Sage Weil 
Reviewed-by: Greg Farnum

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

2012-12-20T22:00:13+00:00

Pull Ceph update from Sage Weil:
 "There are a few different groups of commits here.  The largest is
  Alex's ongoing work to enable the coming RBD features (cloning,
  striping).  There is some cleanup in libceph that goes along with it.

  Cyril and David have fixed some problems with NFS reexport (leaking
  dentries and page locks), and there is a batch of patches from Yan
  fixing problems with the fs client when running against a clustered
  MDS.  There are a few bug fixes mixed in for good measure, many of
  which will be going to the stable trees once they're upstream.

  My apologies for the late pull.  There is still a gremlin in the rbd
  map/unmap code and I was hoping to include the fix for that as well,
  but we haven't been able to confirm the fix is correct yet; I'll send
  that in a separate pull once it's nailed down."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (68 commits)
  rbd: get rid of rbd_{get,put}_dev()
  libceph: register request before unregister linger
  libceph: don't use rb_init_node() in ceph_osdc_alloc_request()
  libceph: init event->node in ceph_osdc_create_event()
  libceph: init osd->o_node in create_osd()
  libceph: report connection fault with warning
  libceph: socket can close in any connection state
  rbd: don't use ENOTSUPP
  rbd: remove linger unconditionally
  rbd: get rid of RBD_MAX_SEG_NAME_LEN
  libceph: avoid using freed osd in __kick_osd_requests()
  ceph: don't reference req after put
  rbd: do not allow remove of mounted-on image
  libceph: Unlock unprocessed pages in start_read() error path
  ceph: call handle_cap_grant() for cap import message
  ceph: Fix __ceph_do_pending_vmtruncate
  ceph: Don't add dirty inode to dirty list if caps is in migration
  ceph: Fix infinite loop in __wake_requests
  ceph: Don't update i_max_size when handling non-auth cap
  bdi_register: add __printf verification, fix arg mismatch
  ...

bdi_register: add __printf verification, fix arg mismatch

2012-12-13T14:13:07+00:00

__printf is useful to verify format and arguments.

Signed-off-by: Joe Perches 
Reviewed-by: Alex Elder

libceph: remove 'osdtimeout' option

2012-12-13T14:13:06+00:00

This would reset a connection with any OSD that had an outstanding
request that was taking more than N seconds.  The idea was that if the
OSD was buggy, the client could compensate by resending the request.

In reality, this only served to hide server bugs, and we haven't
actually seen such a bug in quite a while.  Moreover, the userspace
client code never did this.

More importantly, often the request is taking a long time because the
OSD is trying to recover, or overloaded, and killing the connection
and retrying would only make the situation worse by giving the OSD
more work to do.

Signed-off-by: Sage Weil 
Reviewed-by: Alex Elder

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

2012-10-07T21:38:18+00:00

Pull ceph updates from Sage Weil:
 "The bulk of this pull is a series from Alex that refactors and cleans
  up the RBD code to lay the groundwork for supporting the new image
  format and evolving feature set.  There are also some cleanups in
  libceph, and for ceph there's fixed validation of file striping
  layouts and a bugfix in the code handling a shrinking MDS cluster."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (71 commits)
  ceph: avoid 32-bit page index overflow
  ceph: return EIO on invalid layout on GET_DATALOC ioctl
  rbd: BUG on invalid layout
  ceph: propagate layout error on osd request creation
  libceph: check for invalid mapping
  ceph: convert to use le32_add_cpu()
  ceph: Fix oops when handling mdsmap that decreases max_mds
  rbd: update remaining header fields for v2
  rbd: get snapshot name for a v2 image
  rbd: get the snapshot context for a v2 image
  rbd: get image features for a v2 image
  rbd: get the object prefix for a v2 rbd image
  rbd: add code to get the size of a v2 rbd image
  rbd: lay out header probe infrastructure
  rbd: encapsulate code that gets snapshot info
  rbd: add an rbd features field
  rbd: don't use index in __rbd_add_snap_dev()
  rbd: kill create_snap sysfs entry
  rbd: define rbd_dev_image_id()
  rbd: define some new format constants
  ...

fs: push rcu_barrier() from deactivate_locked_super() to filesystems

2012-10-03T01:35:55+00:00

There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.

Signed-off-by: Kirill A. Shutemov 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

ceph: let path portion of mount "device" be optional

2012-10-01T19:30:49+00:00

A recent change to /sbin/mountall causes any trailing '/' character
in the "device" (or fs_spec) field in /etc/fstab to be stripped.  As
a result, an entry for a ceph mount that intends to mount the root
of the name space ends up with now path portion, and the ceph mount
option processing code rejects this.

That is, an entry in /etc/fstab like:
    cephserver:port:/ /mnt ceph defaults 0 0
provides to the ceph code just "cephserver:port:" as the "device,"
and that gets rejected.

Although this is a bug in /sbin/mountall, we can have the ceph mount
code support an empty/nonexistent path, interpreting it to mean the
root of the name space.

RFC 5952 offers recommendations for how to express IPv6 addresses,
and recommends the usage found in RFC 3986 (which specifies the
format for URI's) for representing both IPv4 and IPv6 addresses that
include port numbers.  (See in particular the definition of
"authority" found in the Appendix of RFC 3986.)

According to those standards, no host specification will ever
contain a '/' character.  As a result, it is sufficient to scan a
provided "device" from an /etc/fstab entry for the first '/'
character, and if it's found, treat that as the beginning of the
path.  If no '/' character is present, we can treat the entire
string as the monitor host specification(s), and assume the path
to be the root of the name space.  We'll still require a ':' to
separate the host portion from the (possibly empty) path portion.

This means that we can more formally define how ceph will interpret
the "device" it's provided when processing a mount request:

    "device" will look like:
        [,...]:[]
    where
         is [:]
         is optional, but if present must begin with '/'

This addresses http://tracker.newdream.net/issues/2919

Signed-off-by: Alex Elder 
Reviewed-by: Dan Mick