As of f025adf1 "sunrpc: Properly decode
kuids and kgids in RPC_AUTH_UNIX credentials" any rpc containing a -1
(0xffff) uid or gid would fail with a badcred error.

Commit afe3c3fd "svcrpc: fix failures to
handle -1 uid's and gid's" fixed part of the problem, but overlooked the
gid upcall--the kernel can request supplementary gid's for the -1 uid,
but mountd's attempt write a response will get -EINVAL.

Symptoms were nfsd failing to reply to the first attempt to use a newly
negotiated krb5 context.
Reported-by: NSven Geggus <lists@fuchsschwanzdomain.de>
Tested-by: NSven Geggus <lists@fuchsschwanzdomain.de>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Calling kthread_run with a single name parameter causes it to be handled
as a format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a cache entry is replaced, the "expiry_time" get set to
zero by a call to "cache_fresh_locked(..., 0)" at the end of
"sunrpc_cache_update".

This low expiry time makes cache_check() think that the 'refresh_age'
is negative, so the 'age' is comparatively large and a refresh is
triggered.
However refreshing a replaced entry it pointless, it cannot achieve
anything useful.

So teach cache_check to ignore a low refresh_age when expiry_time
is zero.
Reported-by: NBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

commit d202cce8
    sunrpc: never return expired entries in sunrpc_cache_lookup

moved the 'entry is expired' test from cache_check to
sunrpc_cache_lookup, so that it happened early and some races could
safely be ignored.

However the ip_map (in svcauth_unix.c) has a separate single-item
cache which allows quick lookup without locking.  An entry in this
case would not be subject to the expiry test and so could be used
well after it has expired.

This is not normally a big problem because the first time it is used
after it is expired an up-call will be scheduled to refresh the entry
(if it hasn't been scheduled already) and the old entry will then
be invalidated.  So on the second attempt to use it after it has
expired, ip_map_cached_get will discard it.

However that is subtle and not ideal, so replace the "!cache_valid"
test with "cache_is_expired".
In doing this we drop the test on the "CACHE_VALID" bit.  This is
unnecessary as the bit is never cleared, and an entry will only
be cached if the bit is set.
Reported-by: NBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It is possible for a race to set CACHE_PENDING after cache_clean()
has removed a cache entry from the cache.
If CACHE_PENDING is still set when the entry is finally 'put',
the cache_dequeue() will never happen and we can leak memory.

So set a new flag 'CACHE_CLEANED' when we remove something from
the cache, and don't queue any upcall if it is set.

If CACHE_PENDING is set before CACHE_CLEANED, the call that
cache_clean() makes to cache_fresh_unlocked() will free memory
as needed.  If CACHE_PENDING is set after CACHE_CLEANED, the
test in sunrpc_cache_pipe_upcall will ensure that the memory
is not allocated.

Reported-by: <bstroesser@ts.fujitsu.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

cache_fresh_unlocked() is called when a cache entry
has been updated and ensures that if there were any
pending upcalls, they are cleared.

So every time we update a cache entry, we should call this,
and this should be the only way that we try to clear
pending calls (that sort of uniformity makes code sooo much
easier to read).

try_to_negate_entry() will (possibly) mark an entry as
negative.  If it doesn't, it is because the entry already
is VALID.
So the entry will be valid on exit, so it is appropriate to
call cache_fresh_unlocked().
So tidy up try_to_negate_entry() to do that, and remove
partial open-coded cache_fresh_unlocked() from the one
call-site of try_to_negate_entry().

In the other branch of the 'switch(cache_make_upcall())',
we again have a partial open-coded version of cache_fresh_unlocked().
Replace that with a real call.

And again in cache_clean(), use a real call to cache_fresh_unlocked().

These call sites might previously have called
cache_revisit_request() if CACHE_PENDING wasn't set.
This is never necessary because cache_revisit_request() can
only do anything if the item is in the cache_defer_hash,
However any time that an item is added to the cache_defer_hash
(setup_deferral), the code immediately tests CACHE_PENDING,
and removes the entry again if it is clear.  So all other
places we only need to 'cache_revisit_request' if we've
just cleared CACHE_PENDING.
Reported-by: NBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NNeilBrown  <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We currently queue an upcall after setting CACHE_PENDING,
and dequeue after clearing CACHE_PENDING.
So a request should only be present when CACHE_PENDING is set.

However we don't combine the test and the enqueue/dequeue in
a protected region, so it is possible (if unlikely) for a race
to result in a request being queued without CACHE_PENDING set,
or a request to be absent despite CACHE_PENDING.

So: include a test for CACHE_PENDING inside the regions of
enqueue and dequeue where queue_lock is held, and abort
the operation if the value is not as expected.

Also remove the early 'return' from cache_dequeue() to ensure that it
always removes all entries: As there is no locking between setting
CACHE_PENDING and calling sunrpc_cache_pipe_upcall it is not
inconceivable for some other thread to clear CACHE_PENDING and then
someone else to set it and call sunrpc_cache_pipe_upcall, both before
the original threads completed the call.

With this, it perfectly safe and correct to:
 - call cache_dequeue() if and only if we have just
   cleared CACHE_PENDING
 - call sunrpc_cache_pipe_upcall() (via cache_make_upcall)
   if and only if we have just set CACHE_PENDING.
Reported-by: NBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NBodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Though clients we care about mostly don't do this, it is possible for
rpc requests to be sent in multiple fragments.  Here we have a sanity
check to ensure that the final received rpc isn't too small--except that
the number we're actually checking is the length of just the final
fragment, not of the whole rpc.  So a perfectly legal rpc that's
unluckily fragmented could cause the server to close the connection
here.

Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we detect that an rpc is too short, we abort and close the
connection.  Except, there's a bug here: we're leaving sk_datalen
nonzero without leaving any pages in the sk_pages array.  The most
likely result of the inconsistency is a subsequent crash in
svc_tcp_clear_pages.

Also demote the BUG_ON in svc_tcp_clear_pages to a WARN.

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Store a pointer to the gss mechanism used in the rq_cred and cl_cred.
This will make it easier to enforce SP4_MACH_CRED, which needs to
compare the mechanism used on the exchange_id with that used on
protected operations.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Common helper to zero out fields of the svc_cred.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Not need to create pipes for dying client. So just skip them.

Note: we can safely dereference the client structure, because notification
caller is holding sn->pipefs_sb_lock.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This helper moves all "registration" code to the new rpc_client_register()
helper.
This helper will be used later in the series to synchronize against PipeFS
MOUNT/UMOUNT events.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

CPU#0                                   CPU#1
-----------------------------           -----------------------------
rpc_kill_sb
sn->pipefs_sb = NULL                    rpc_release_client
(UMOUNT_EVENT)                          rpc_free_auth
rpc_pipefs_event
rpc_get_client_for_event
!atomic_inc_not_zero(cl_count)
<skip the client>
                                        atomic_inc(cl_count)
                                        rpc_free_client
                                        rpc_clnt_remove_pipedir
                                        <skip client dir removing>

To fix this, this patch does the following:

1) Calls RPC_PIPEFS_UMOUNT notification with sn->pipefs_sb_lock being held.
2) Removes SUNRPC client from the list AFTER pipes destroying.
3) Doesn't hold RPC client on notification: if client in the list, then it
can't be destroyed while sn->pipefs_sb_lock in hold by notification caller.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Below are races, when RPC client can be created without PiepFS dentries

CPU#0					CPU#1
-----------------------------		-----------------------------
rpc_new_client				rpc_fill_super
rpc_setup_pipedir
mutex_lock(&sn->pipefs_sb_lock)
rpc_get_sb_net == NULL
(no per-net PipeFS superblock)
					sn->pipefs_sb = sb;
					notifier_call_chain(MOUNT)
					(client is not in the list)
rpc_register_client
(client without pipes dentries)

To fix this patch:
1) makes PipeFS mount notification call with pipefs_sb_lock being held.
2) releases pipefs_sb_lock on new SUNRPC client creation only after
registration.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We had a report of a reproducible WARNING:

[ 1360.039358] ------------[ cut here ]------------
[ 1360.043978] WARNING: at fs/dcache.c:1355 d_set_d_op+0x8d/0xc0()
[ 1360.049880] Hardware name: HP Z200 Workstation
[ 1360.054308] Modules linked in: nfsv4 nfs dns_resolver fscache nfsd
auth_rpcgss nfs_acl lockd sunrpc sg acpi_cpufreq mperf coretemp kvm_intel kvm
snd_hda_codec_realtek snd_hda_intel snd_hda_codec hp_wmi crc32c_intel
snd_hwdep e1000e snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer snd
sparse_keymap rfkill soundcore serio_raw ptp iTCO_wdt pps_core pcspkr
iTCO_vendor_support mei microcode lpc_ich mfd_core wmi xfs libcrc32c sr_mod
sd_mod cdrom crc_t10dif radeon i2c_algo_bit drm_kms_helper ttm ahci libahci
drm i2c_core libata dm_mirror dm_region_hash dm_log dm_mod [last unloaded:
auth_rpcgss]
[ 1360.107406] Pid: 8814, comm: mount.nfs4 Tainted: G         I --------------   3.9.0-0.55.el7.x86_64 #1
[ 1360.116771] Call Trace:
[ 1360.119219]  [<ffffffff810610c0>] warn_slowpath_common+0x70/0xa0
[ 1360.125208]  [<ffffffff810611aa>] warn_slowpath_null+0x1a/0x20
[ 1360.131025]  [<ffffffff811af46d>] d_set_d_op+0x8d/0xc0
[ 1360.136159]  [<ffffffffa05a7d6f>] __rpc_lookup_create_exclusive+0x4f/0x80 [sunrpc]
[ 1360.143710]  [<ffffffffa05a8cc6>] rpc_mkpipe_dentry+0x86/0x170 [sunrpc]
[ 1360.150311]  [<ffffffffa062a7b6>] nfs_idmap_new+0x96/0x130 [nfsv4]
[ 1360.156475]  [<ffffffffa062e7cd>] nfs4_init_client+0xad/0x2d0 [nfsv4]
[ 1360.162902]  [<ffffffff812f02df>] ? idr_get_empty_slot+0x16f/0x3c0
[ 1360.169062]  [<ffffffff812f0582>] ? idr_mark_full+0x52/0x60
[ 1360.174615]  [<ffffffff812f0699>] ? idr_alloc+0x79/0xe0
[ 1360.179826]  [<ffffffffa0598081>] ? __rpc_init_priority_wait_queue+0x81/0xc0 [sunrpc]
[ 1360.187635]  [<ffffffffa05980f3>] ? rpc_init_wait_queue+0x13/0x20 [sunrpc]
[ 1360.194493]  [<ffffffffa05d05da>] nfs_get_client+0x27a/0x350 [nfs]
[ 1360.200666]  [<ffffffffa062e438>] nfs4_set_client.isra.8+0x78/0x100 [nfsv4]
[ 1360.207624]  [<ffffffffa062f2f3>] nfs4_create_server+0xf3/0x3a0 [nfsv4]
[ 1360.214222]  [<ffffffffa06284be>] nfs4_remote_mount+0x2e/0x60 [nfsv4]
[ 1360.220644]  [<ffffffff8119ea79>] mount_fs+0x39/0x1b0
[ 1360.225691]  [<ffffffff81153880>] ? __alloc_percpu+0x10/0x20
[ 1360.231348]  [<ffffffff811b7ccf>] vfs_kern_mount+0x5f/0xf0
[ 1360.236822]  [<ffffffffa0628396>] nfs_do_root_mount+0x86/0xc0 [nfsv4]
[ 1360.243246]  [<ffffffffa06287b4>] nfs4_try_mount+0x44/0xc0 [nfsv4]
[ 1360.249410]  [<ffffffffa05d1457>] ? get_nfs_version+0x27/0x80 [nfs]
[ 1360.255659]  [<ffffffffa05db985>] nfs_fs_mount+0x5c5/0xd10 [nfs]
[ 1360.261650]  [<ffffffffa05dc550>] ? nfs_clone_super+0x140/0x140 [nfs]
[ 1360.268074]  [<ffffffffa05da8e0>] ? param_set_portnr+0x60/0x60 [nfs]
[ 1360.274406]  [<ffffffff8119ea79>] mount_fs+0x39/0x1b0
[ 1360.279443]  [<ffffffff81153880>] ? __alloc_percpu+0x10/0x20
[ 1360.285088]  [<ffffffff811b7ccf>] vfs_kern_mount+0x5f/0xf0
[ 1360.290556]  [<ffffffff811b9f5d>] do_mount+0x1fd/0xa00
[ 1360.295677]  [<ffffffff81137dee>] ? __get_free_pages+0xe/0x50
[ 1360.301405]  [<ffffffff811b9be6>] ? copy_mount_options+0x36/0x170
[ 1360.307479]  [<ffffffff811ba7e3>] sys_mount+0x83/0xc0
[ 1360.312515]  [<ffffffff8160ad59>] system_call_fastpath+0x16/0x1b
[ 1360.318503] ---[ end trace 8fa1f4cbc36094a7 ]---

The problem is that we're ending up in __rpc_lookup_create_exclusive
with a negative dentry that already has d_op set. A little debugging
has shown that when we hit this, the d_ops are already set to
simple_dentry_operations.

I believe that what's happening is that during a mount, idmapd is racing
in and doing a lookup of /var/lib/nfs/rpc_pipefs/nfs/clnt???/idmap.
Before that dentry reference is released, the kernel races in to create
that file and finds the new negative dentry, which already has the
d_op set.

This patch just avoids setting the d_op if it's already set.
simple_dentry_operations and rpc_dentry_operations are functionally
equivalent so it shouldn't matter which one it's set to.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Reduce the uses of this unnecessary typedef.

Done via perl script:

$ git grep --name-only -w ctl_table net | \
  xargs perl -p -i -e '\
	sub trim { my ($local) = @_; $local =~ s/(^\s+|\s+$)//g; return $local; } \
        s/\b(?<!struct\s)ctl_table\b(\s*\*\s*|\s+\w+)/"struct ctl_table " . trim($1)/ge'

Reflow the modified lines that now exceed 80 columns.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RPC_TASK_RUNNING flag will always have been set in rpc_make_runnable()
once we get past the test for out_of_line_wait_on_bit() returning
ERESTARTSYS.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the rpc_task is asynchronous, it could theoretically finish executing
on the workqueue it was assigned by rpc_make_runnable() before we get
round to testing RPC_IS_ASYNC() in rpc_execute.

In practice, however, all the existing callers hold a reference to the
rpc_task, so this can't happen today...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

As of f025adf1 "sunrpc: Properly decode
kuids and kgids in RPC_AUTH_UNIX credentials" any rpc containing a -1
(0xffff) uid or gid would fail with a badcred error.

Reported symptoms were xmbc clients failing on upgrade of the NFS
server; examination of the network trace showed them sending -1 as the
gid.
Reported-by: NJulian Sikorski <belegdol@gmail.com>
Tested-by: NJulian Sikorski <belegdol@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Somebody noticed LTP was complaining about O_NONBLOCK opens of
/proc/net/rpc/use-gss-proxy succeeding and then a following read
hanging.

I'm not convinced LTP really has any business opening random proc files
and expecting them to behave a certain way.  Maybe this isn't really a
bug.

But in any case the O_NONBLOCK behavior could be useful for someone that
wants to test whether gss-proxy is up without waiting.
Reported-by: NJan Stancek <jstancek@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The lockless RPC_IS_QUEUED() test in __rpc_execute means that we need to
be careful about ordering the calls to rpc_test_and_set_running(task) and
rpc_clear_queued(task). If we get the order wrong, then we may end up
testing the RPC_TASK_RUNNING flag after __rpc_execute() has looped
and changed the state of the rpc_task.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

The cache_detail(*detail) in function cache_is_valid is not used any
more.
Signed-off-by: Nfanchaoting <fanchaoting@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This seems to have been overlooked when we did the namespace
conversion. If a container is running a legacy version of rpc.gssd
then it will be disrupted if the global 'pipe_version' is set by a
container running the new version of rpc.gssd.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Recent changes to the NFS security flavour negotiation mean that
we have a stronger dependency on rpc.gssd. If the latter is not
running, because the user failed to start it, then we time out
and mark the container as not having an instance. We then
use that information to time out faster the next time.

If, on the other hand, the rpc.gssd successfully binds to an rpc_pipe,
then we mark the container as having an rpc.gssd instance.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If wait_event_interruptible_timeout() is successful, it returns
the number of seconds remaining until the timeout. In that
case, we should be retrying the upcall.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

XPRT_BOUND is set on server backchannel xprts by xs_setup_bc_tcp()
(using xprt_set_bound()), and is never cleared, so ->rpcbind() will
never need to be called.
Reported-by: N"Myklebust, Trond" <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This should return zero on success and -EBUSY on error so the type
needs to be int instead of bool.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

NFS calls the freezable helpers with locks held, which is unsafe
and will cause lockdep warnings when 6aa97070 "lockdep: check
that no locks held at freeze time" is reapplied (it was reverted
in dbf520a9).  NFS shouldn't be doing this, but it has
long-running syscalls that must hold a lock but also shouldn't
block suspend.  Until NFS freeze handling is rewritten to use a
signal to exit out of the critical section, add new *_unsafe
versions of the helpers that will not run the lockdep test when
6aa97070 is reapplied, and call them from NFS.

In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock.  Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.
Signed-off-by: NColin Cross <ccross@android.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The current code works, but sort of by accident: it obviously didn't
intend the error return to be interpreted as "true".
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

net/sunrpc/auth_gss/gss_rpc_xdr.c: In function ‘gssx_dec_option_array’:
net/sunrpc/auth_gss/gss_rpc_xdr.c:258: warning: ‘creds’ may be used uninitialized in this function

Return early if count is zero, to make it clearer to the compiler (and the
casual reviewer) that no more processing is done.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Just convert those messages to dprintk()s so that they can be used
when debugging.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Use preferable function name which implies using a pseudo-random
number generator.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are at least two users of isodigit().  Let's make it a public
function of ctype.h.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Cc: Simo Sorce <simo@redhat.com>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>

Though I wonder whether we should really just depend on CONFIG_PROC_FS
at some point.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>