linux-stable.git/net/sunrpc, branch v3.16.78

sunrpc: don't mark uninitialised items as VALID.

2019-08-13T11:39:03+00:00

commit d58431eacb226222430940134d97bfd72f292fcd upstream.

A recent commit added a call to cache_fresh_locked()
when an expired item was found.
The call sets the CACHE_VALID flag, so it is important
that the item actually is valid.
There are two ways it could be valid:
1/ If ->update has been called to fill in relevant content
2/ if CACHE_NEGATIVE is set, to say that content doesn't exist.

An expired item that is waiting for an update will be neither.
Setting CACHE_VALID will mean that a subsequent call to cache_put()
will be likely to dereference uninitialised pointers.

So we must make sure the item is valid, and we already have code to do
that in try_to_negate_entry().  This takes the hash lock and so cannot
be used directly, so take out the two lines that we need and use them.

Now cache_fresh_locked() is certain to be called only on
a valid item.

Fixes: 4ecd55ea0742 ("sunrpc: fix cache_head leak due to queued request")
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

sunrpc: use SVC_NET() in svcauth_gss_* functions

2019-04-04T15:14:07+00:00

commit b8be5674fa9a6f3677865ea93f7803c4212f3e10 upstream.

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

sunrpc: fix cache_head leak due to queued request

2019-04-04T15:13:46+00:00

commit 4ecd55ea074217473f94cfee21bb72864d39f8d7 upstream.

After commit d202cce8963d, an expired cache_head can be removed from the
cache_detail's hash.

However, the expired cache_head may be waiting for a reply from a
previously submitted request. Such a cache_head has an increased
refcounter and therefore it won't be freed after cache_put(freeme).

Because the cache_head was removed from the hash it cannot be found
during cache_clean() and can be leaked forever, together with stalled
cache_request and other taken resources.

In our case we noticed it because an entry in the export cache was
holding a reference on a filesystem.

Fixes d202cce8963d ("sunrpc: never return expired entries in sunrpc_cache_lookup")
Cc: Pavel Tikhomirov 
Signed-off-by: Vasily Averin 
Reviewed-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
[bwh: Backported to 3.16:
 - cache_fresh_lock() doesn't take a struct cache_detail pointer
 - Adjust context]
Signed-off-by: Ben Hutchings

sunrpc: use-after-free in svc_process_common()

2019-03-25T17:32:32+00:00

commit d4b09acf924b84bae77cad090a9d108e70b43643 upstream.

if node have NFSv41+ mounts inside several net namespaces
it can lead to use-after-free in svc_process_common()

svc_process_common()
        /* Setup reply header */
        rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp); <<< HERE

svc_process_common() can use incorrect rqstp->rq_xprt,
its caller function bc_svc_process() takes it from serv->sv_bc_xprt.
The problem is that serv is global structure but sv_bc_xprt
is assigned per-netnamespace.

According to Trond, the whole "let's set up rqstp->rq_xprt
for the back channel" is nothing but a giant hack in order
to work around the fact that svc_process_common() uses it
to find the xpt_ops, and perform a couple of (meaningless
for the back channel) tests of xpt_flags.

All we really need in svc_process_common() is to be able to run
rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr()

Bruce J Fields points that this xpo_prep_reply_hdr() call
is an awfully roundabout way just to do "svc_putnl(resv, 0);"
in the tcp case.

This patch does not initialiuze rqstp->rq_xprt in bc_svc_process(),
now it calls svc_process_common() with rqstp->rq_xprt = NULL.

To adjust reply header svc_process_common() just check
rqstp->rq_prot and calls svc_tcp_prep_reply_hdr() for tcp case.

To handle rqstp->rq_xprt = NULL case in functions called from
svc_process_common() patch intruduces net namespace pointer
svc_rqst->rq_bc_net and adjust SVC_NET() definition.
Some other function was also adopted to properly handle described case.

Signed-off-by: Vasily Averin 
Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup")
Signed-off-by: J. Bruce Fields 
v2: - added lost extern svc_tcp_prep_reply_hdr()
    - context changes in svc_process_common()
    - dropped trace_svc_process() changes
Signed-off-by: Vasily Averin 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

SUNRPC: Fix a potential race in xprt_connect()

2019-02-11T17:54:17+00:00

commit 0a9a4304f3614e25d9de9b63502ca633c01c0d70 upstream.

If an asynchronous connection attempt completes while another task is
in xprt_connect(), then the call to rpc_sleep_on() could end up
racing with the call to xprt_wake_pending_tasks().
So add a second test of the connection state after we've put the
task to sleep and set the XPRT_CONNECTING flag, when we know that there
can be no asynchronous connection attempts still in progress.

Fixes: 0b9e79431377d ("SUNRPC: Move the test for XPRT_CONNECTING into...")
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

SUNRPC: Fix leak of krb5p encode pages

2019-02-11T17:54:17+00:00

commit 8dae5398ab1ac107b1517e8195ed043d5f422bd0 upstream.

call_encode can be invoked more than once per RPC call. Ensure that
each call to gss_wrap_req_priv does not overwrite pointers to
previously allocated memory.

Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

SUNRPC: drop pointless static qualifier in xdr_get_next_encode_buffer()

2019-02-11T17:53:54+00:00

commit 025911a5f4e36955498ed50806ad1b02f0f76288 upstream.

There is no need to have the '__be32 *p' variable static since new value
always be assigned before use it.

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

sunrpc: correct the computation for page_ptr when truncating

2019-02-11T17:53:48+00:00

commit 5d7a5bcb67c70cbc904057ef52d3fcfeb24420bb upstream.

When truncating the encode buffer, the page_ptr is getting
advanced, causing the next page to be skipped while encoding.
The page is still included in the response, so the response
contains a page of bogus data.

We need to adjust the page_ptr backwards to ensure we encode
the next page into the correct place.

We saw this triggered when concurrent directory modifications caused
nfsd4_encode_direct_fattr() to return nfserr_noent, and the resulting
call to xdr_truncate_encode() corrupted the READDIR reply.

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

nfsd: Fix an Oops in free_session()

2019-02-11T17:53:43+00:00

commit bb6ad5572c0022e17e846b382d7413cdcf8055be upstream.

In call_xpt_users(), we delete the entry from the list, but we
do not reinitialise it. This triggers the list poisoning when
we later call unregister_xpt_user() in nfsd4_del_conns().

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

rpc_pipefs: fix double-dput()

2018-10-21T07:45:26+00:00

commit 4a3877c4cedd95543f8726b0a98743ed8db0c0fb upstream.

if we ever hit rpc_gssd_dummy_depopulate() dentry passed to
it has refcount equal to 1.  __rpc_rmpipe() drops it and
dput() done after that hits an already freed dentry.

Signed-off-by: Al Viro 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings