linux-stable.git/fs/nfsd, branch v3.2.78

nfsd: fix the check for confirmed openowner in nfs4_preprocess_stateid_op

2015-08-06T23:32:09+00:00

commit ebe9cb3bb13e7b9b281969cd279ce70834f7500f upstream.

If we find a non-confirmed openowner we jump to exit the function, but do
not set an error value.  Fix this by factoring out a helper to do the
check and properly set the error from nfsd4_validate_stateid.

Signed-off-by: Christoph Hellwig 
Signed-off-by: J. Bruce Fields 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

nfsd: Fix slot wake up race in the nfsv4.1 callback code

2014-12-14T16:23:58+00:00

commit c6c15e1ed303ffc47e696ea1c9a9df1761c1f603 upstream.

The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.

Task 1                                  Task 2
======                                  ======
if (test_and_set_bit(0) != 0) {
                                        clear_bit(0)
                                        rpc_wake_up_next(queue)
        rpc_sleep_on(queue)
        return false;
}

This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().

Signed-off-by: Trond Myklebust 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd4: fix crash on unknown operation number

2014-12-14T16:23:50+00:00

commit 51904b08072a8bf2b9ed74d1bd7a5300a614471d upstream.

Unknown operation numbers are caught in nfsd4_decode_compound() which
sets op->opnum to OP_ILLEGAL and op->status to nfserr_op_illegal.  The
error causes the main loop in nfsd4_proc_compound() to skip most
processing.  But nfsd4_proc_compound also peeks ahead at the next
operation in one case and doesn't take similar precautions there.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd: Fix ACL null pointer deref

2014-11-05T20:27:49+00:00

BugLink: http://bugs.launchpad.net/bugs/1348670

Fix regression introduced in pre-3.14 kernels by cherry-picking
aa07c713ecfc0522916f3cd57ac628ea6127c0ec
(NFSD: Call ->set_acl with a NULL ACL structure if no entries).

The affected code was removed in 3.14 by commit
4ac7249ea5a0ceef9f8269f63f33cc873c3fac61
(nfsd: use get_acl and ->set_acl).
The ->set_acl methods are already able to cope with a NULL argument.

Signed-off-by: Sergio Gelato 
[bwh: Rewrite the subject]
Signed-off-by: Ben Hutchings

nfsd: fix rare symlink decoding bug

2014-08-06T17:07:33+00:00

commit 76f47128f9b33af1e96819746550d789054c9664 upstream.

An NFS operation that creates a new symlink includes the symlink data,
which is xdr-encoded as a length followed by the data plus 0 to 3 bytes
of zero-padding as required to reach a 4-byte boundary.

The vfs, on the other hand, wants null-terminated data.

The simple way to handle this would be by copying the data into a newly
allocated buffer with space for the final null.

The current nfsd_symlink code tries to be more clever by skipping that
step in the (likely) case where the byte following the string is already
0.

But that assumes that the byte following the string is ours to look at.
In fact, it might be the first byte of a page that we can't read, or of
some object that another task might modify.

Worse, the NFSv4 code tries to fix the problem by actually writing to
that byte.

In the NFSv2/v3 cases this actually appears to be safe:

	- nfs3svc_decode_symlinkargs explicitly null-terminates the data
	  (after first checking its length and copying it to a new
	  page).
	- NFSv2 limits symlinks to 1k.  The buffer holding the rpc
	  request is always at least a page, and the link data (and
	  previous fields) have maximum lengths that prevent the request
	  from reaching the end of a page.

In the NFSv4 case the CREATE op is potentially just one part of a long
compound so can end up on the end of a page if you're unlucky.

The minimal fix here is to copy and null-terminate in the NFSv4 case.
The nfsd_symlink() interface here seems too fragile, though.  It should
really either do the copy itself every time or just require a
null-terminated string.

Reported-by: Jeff Layton 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd4: fix FREE_STATEID lockowner leak

2014-07-11T12:33:48+00:00

commit 48385408b45523d9a432c66292d47ef43efcbb94 upstream.

27b11428b7de ("nfsd4: remove lockowner when removing lock stateid")
introduced a memory leak.

Reported-by: Jeff Layton 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd4: use recall_lock for delegation hashing

2014-07-11T12:33:46+00:00

commit 931ee56c67573eb4e51c8a4e78598d965b8b059e upstream.

This fixes a bug in the handling of the fi_delegations list.

nfs4_setlease does not hold the recall_lock when adding to it. The
client_mutex is held, which prevents against concurrent list changes,
but nfsd_break_deleg_cb does not hold while walking it. New delegations
could theoretically creep onto the list while we're walking it there.

Signed-off-by: Benny Halevy 
Signed-off-by: Jeff Layton 
Signed-off-by: J. Bruce Fields 
[bwh: Backported to 3.2:
 - Adjust context
 - Also remove a list_del_init() in nfs4_setlease() which would now be
   before the corresponding list_add()
 - Drop change to nfsd_find_all_delegations(), which doesn't exist]
Signed-off-by: Ben Hutchings

nfsd: getattr for FATTR4_WORD0_FILES_AVAIL needs the statfs buffer

2014-07-11T12:33:44+00:00

commit 12337901d654415d9f764b5f5ba50052e9700f37 upstream.

Note nobody's ever noticed because the typical client probably never
requests FILES_AVAIL without also requesting something else on the list.

Signed-off-by: Christoph Hellwig 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd4: warn on finding lockowner without stateid's

2014-06-09T12:29:15+00:00

commit 27b11428b7de097c42f205beabb1764f4365443b upstream.

The current code assumes a one-to-one lockowner<->lock stateid
correspondance.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

nfsd4: remove lockowner when removing lock stateid

2014-06-09T12:29:14+00:00

commit a1b8ff4c97b4375d21b6d6c45d75877303f61b3b upstream.

The nfsv4 state code has always assumed a one-to-one correspondance
between lock stateid's and lockowners even if it appears not to in some
places.

We may actually change that, but for now when FREE_STATEID releases a
lock stateid it also needs to release the parent lockowner.

Symptoms were a subsequent LOCK crashing in find_lockowner_str when it
calls same_lockowner_ino on a lockowner that unexpectedly has an empty
so_stateids list.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings