linux-toradex.git/net/sunrpc/svcauth_unix.c, branch v4.4.6

svcrpc: fix failures to handle -1 uid's

2013-07-08T21:27:23+00:00

As of f025adf191924e3a75ce80e130afcd2485b53bb8 "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 afe3c3fd5392b2f0066930abc5dbd3f4b14a0f13 "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: Sven Geggus 
Tested-by: Sven Geggus 
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields

net/sunrpc: xpt_auth_cache should be ignored when expired.

2013-07-01T21:53:28+00:00

commit d202cce8963d9268ff355a386e20243e8332b308
    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: Bodo Stroesser 
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields

svcrpc: fix failures to handle -1 uid's and gid's

2013-05-29T14:37:47+00:00

As of f025adf191924e3a75ce80e130afcd2485b53bb8 "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: Julian Sikorski 
Tested-by: Julian Sikorski 
Cc: "Eric W. Biederman" 
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields

Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux

2013-03-01T02:02:55+00:00

Pull nfsd changes from J Bruce Fields:
 "Miscellaneous bugfixes, plus:

   - An overhaul of the DRC cache by Jeff Layton.  The main effect is
     just to make it larger.  This decreases the chances of intermittent
     errors especially in the UDP case.  But we'll need to watch for any
     reports of performance regressions.

   - Containerized nfsd: with some limitations, we now support
     per-container nfs-service, thanks to extensive work from Stanislav
     Kinsbursky over the last year."

Some notes about conflicts, since there were *two* non-data semantic
conflicts here:

 - idr_remove_all() had been added by a memory leak fix, but has since
   become deprecated since idr_destroy() does it for us now.

 - xs_local_connect() had been added by this branch to make AF_LOCAL
   connections be synchronous, but in the meantime Trond had changed the
   calling convention in order to avoid a RCU dereference.

There were a couple of more obvious actual source-level conflicts due to
the hlist traversal changes and one just due to code changes next to
each other, but those were trivial.

* 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits)
  SUNRPC: make AF_LOCAL connect synchronous
  nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum
  svcrpc: fix rpc server shutdown races
  svcrpc: make svc_age_temp_xprts enqueue under sv_lock
  lockd: nlmclnt_reclaim(): avoid stack overflow
  nfsd: enable NFSv4 state in containers
  nfsd: disable usermode helper client tracker in container
  nfsd: use proper net while reading "exports" file
  nfsd: containerize NFSd filesystem
  nfsd: fix comments on nfsd_cache_lookup
  SUNRPC: move cache_detail->cache_request callback call to cache_read()
  SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function
  SUNRPC: rework cache upcall logic
  SUNRPC: introduce cache_detail->cache_request callback
  NFS: simplify and clean cache library
  NFS: use SUNRPC cache creation and destruction helper for DNS cache
  nfsd4: free_stid can be static
  nfsd: keep a checksum of the first 256 bytes of request
  sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
  sunrpc: fix comment in struct xdr_buf definition
  ...

SUNRPC: rework cache upcall logic

2013-02-15T15:43:46+00:00

For most of SUNRPC caches (except NFS DNS cache) cache_detail->cache_upcall is
redundant since all that it's implementations are doing is calling
sunrpc_cache_pipe_upcall() with proper function address argument.
Cache request function address is now stored on cache_detail structure and
thus all the code can be simplified.
Now, for those cache details, which doesn't have cache_upcall callback (the
only one, which still has is nfs_dns_resolve_template)
sunrpc_cache_pipe_upcall will be called instead.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields

SUNRPC: introduce cache_detail->cache_request callback

2013-02-15T15:43:45+00:00

This callback will allow to simplify upcalls in further patches in this
series.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields

sunrpc: Properly decode kuids and kgids in RPC_AUTH_UNIX credentials

2013-02-13T14:15:26+00:00

When reading kuids from the wire map them into the initial user
namespace, and validate the mapping succeded.

When reading kgids from the wire map them into the initial user
namespace, and validate the mapping succeded.

Cc: "J. Bruce Fields" 
Cc: Trond Myklebust 
Signed-off-by: "Eric W. Biederman"

sunrpc: Properly encode kuids and kgids in auth.unix.gid rpc pipe upcalls.

2013-02-13T14:15:25+00:00

When a new rpc connection is established with an in-kernel server, the
traffic passes through svc_process_common, and svc_set_client and down
into svcauth_unix_set_client if it is of type RPC_AUTH_NULL or
RPC_AUTH_UNIX.

svcauth_unix_set_client then looks at the uid of the credential we
have assigned to the incomming client and if we don't have the groups
already cached makes an upcall to get a list of groups that the client
can use.

The upcall encodes send a rpc message to user space encoding the uid
of the user whose groups we want to know.  Encode the kuid of the user
in the initial user namespace as nfs mounts can only happen today in
the initial user namespace.

When a reply to an upcall comes in convert interpret the uid and gid values
from the rpc pipe as uids and gids in the initial user namespace and convert
them into kuids and kgids before processing them further.

When reading proc files listing the uid to gid list cache convert the
kuids and kgids from into uids and gids the initial user namespace.  As we are
displaying server internal details it makes sense to display these values
from the servers perspective.

Cc: "J. Bruce Fields" 
Cc: Trond Myklebust 
Signed-off-by: "Eric W. Biederman"

sunrpc: Hash uids by first computing their value in the initial userns

2013-02-13T14:15:23+00:00

In svcauth_unix introduce a helper unix_gid_hash as otherwise the
expresion to generate the hash value is just too long.

Cc: "J. Bruce Fields" 
Cc: Trond Myklebust 
Signed-off-by: "Eric W. Biederman"

sunrpc: Use uid_eq and gid_eq where appropriate

2013-02-13T14:15:17+00:00

When comparing uids use uid_eq instead of ==.
When comparing gids use gid_eq instead of ==.

And unfortunate cost of type safety.

Cc: "J. Bruce Fields" 
Cc: Trond Myklebust 
Signed-off-by: "Eric W. Biederman"