linux-stable.git/net/sunrpc, branch linux-3.18.y

sunrpc: don't mark uninitialised items as VALID.

2019-05-16T07:17:13+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.

Cc: stable@kernel.org # 2.6.35
Fixes: 4ecd55ea0742 ("sunrpc: fix cache_head leak due to queued request")
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

sunrpc: handle ENOMEM in rpcb_getport_async

2019-01-26T08:44:26+00:00

commit 81c88b18de1f11f70c97f28ced8d642c00bb3955 upstream.

If we ignore the error we'll hit a null dereference a little later.

Reported-by: syzbot+4b98281f2401ab849f4b@syzkaller.appspotmail.com
Signed-off-by: J. Bruce Fields 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

sunrpc: use-after-free in svc_process_common()

2019-01-26T08:44:24+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 
Cc: stable@vger.kernel.org
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

sunrpc: use SVC_NET() in svcauth_gss_* functions

2019-01-13T09:07:11+00:00

commit b8be5674fa9a6f3677865ea93f7803c4212f3e10 upstream.

Signed-off-by: Vasily Averin 
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

sunrpc: fix cache_head leak due to queued request

2019-01-13T09:07:11+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 
Cc: stable@kernel.org # 2.6.35
Signed-off-by: Vasily Averin 
Reviewed-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

sock: Make sock->sk_stamp thread-safe

2019-01-13T09:07:10+00:00

[ Upstream commit 3a0ed3e9619738067214871e9cb826fa23b2ddb9 ]

Al Viro mentioned (Message-ID
<20170626041334.GZ10672@ZenIV.linux.org.uk>)
that there is probably a race condition
lurking in accesses of sk_stamp on 32-bit machines.

sock->sk_stamp is of type ktime_t which is always an s64.
On a 32 bit architecture, we might run into situations of
unsafe access as the access to the field becomes non atomic.

Use seqlocks for synchronization.
This allows us to avoid using spinlocks for readers as
readers do not need mutual exclusion.

Another approach to solve this is to require sk_lock for all
modifications of the timestamps. The current approach allows
for timestamps to have their own lock: sk_stamp_lock.
This allows for the patch to not compete with already
existing critical sections, and side effects are limited
to the paths in the patch.

The addition of the new field maintains the data locality
optimizations from
commit 9115e8cd2a0c ("net: reorganize struct sock for better data
locality")

Note that all the instances of the sk_stamp accesses
are either through the ioctl or the syscall recvmsg.

Signed-off-by: Deepa Dinamani 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a potential race in xprt_connect()

2018-12-21T13:08:48+00:00

[ Upstream commit 0a9a4304f3614e25d9de9b63502ca633c01c0d70 ]

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: Sasha Levin

SUNRPC: Fix leak of krb5p encode pages

2018-12-13T08:22:31+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 
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a bogus get/put in generic_key_to_expire()

2018-12-01T08:47:59+00:00

[ Upstream commit e3d5e573a54dabdc0f9f3cb039d799323372b251 ]

Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

SUNRPC: drop pointless static qualifier in xdr_get_next_encode_buffer()

2018-11-27T15:05:37+00:00

[ Upstream commit 025911a5f4e36955498ed50806ad1b02f0f76288 ]

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

Signed-off-by: YueHaibing 
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin