linux-stable.git/include/linux/sunrpc, branch v4.19.282

SUNRPC: ensure the matching upcall is in-flight upon downcall

2023-01-18T10:30:49+00:00

[ Upstream commit b18cba09e374637a0a3759d856a6bca94c133952 ]

Commit 9130b8dbc6ac ("SUNRPC: allow for upcalls for the same uid
but different gss service") introduced `auth` argument to
__gss_find_upcall(), but in gss_pipe_downcall() it was left as NULL
since it (and auth->service) was not (yet) determined.

When multiple upcalls with the same uid and different service are
ongoing, it could happen that __gss_find_upcall(), which returns the
first match found in the pipe->in_downcall list, could not find the
correct gss_msg corresponding to the downcall we are looking for.
Moreover, it might return a msg which is not sent to rpc.gssd yet.

We could see mount.nfs process hung in D state with multiple mount.nfs
are executed in parallel.  The call trace below is of CentOS 7.9
kernel-3.10.0-1160.24.1.el7.x86_64 but we observed the same hang w/
elrepo kernel-ml-6.0.7-1.el7.

PID: 71258  TASK: ffff91ebd4be0000  CPU: 36  COMMAND: "mount.nfs"
 #0 [ffff9203ca3234f8] __schedule at ffffffffa3b8899f
 #1 [ffff9203ca323580] schedule at ffffffffa3b88eb9
 #2 [ffff9203ca323590] gss_cred_init at ffffffffc0355818 [auth_rpcgss]
 #3 [ffff9203ca323658] rpcauth_lookup_credcache at ffffffffc0421ebc
[sunrpc]
 #4 [ffff9203ca3236d8] gss_lookup_cred at ffffffffc0353633 [auth_rpcgss]
 #5 [ffff9203ca3236e8] rpcauth_lookupcred at ffffffffc0421581 [sunrpc]
 #6 [ffff9203ca323740] rpcauth_refreshcred at ffffffffc04223d3 [sunrpc]
 #7 [ffff9203ca3237a0] call_refresh at ffffffffc04103dc [sunrpc]
 #8 [ffff9203ca3237b8] __rpc_execute at ffffffffc041e1c9 [sunrpc]
 #9 [ffff9203ca323820] rpc_execute at ffffffffc0420a48 [sunrpc]

The scenario is like this. Let's say there are two upcalls for
services A and B, A -> B in pipe->in_downcall, B -> A in pipe->pipe.

When rpc.gssd reads pipe to get the upcall msg corresponding to
service B from pipe->pipe and then writes the response, in
gss_pipe_downcall the msg corresponding to service A will be picked
because only uid is used to find the msg and it is before the one for
B in pipe->in_downcall.  And the process waiting for the msg
corresponding to service A will be woken up.

Actual scheduing of that process might be after rpc.gssd processes the
next msg.  In rpc_pipe_generic_upcall it clears msg->errno (for A).
The process is scheduled to see gss_msg->ctx == NULL and
gss_msg->msg.errno == 0, therefore it cannot break the loop in
gss_create_upcall and is never woken up after that.

This patch adds a simple check to ensure that a msg which is not
sent to rpc.gssd yet is not chosen as the matching upcall upon
receiving a downcall.

Signed-off-by: minoura makoto 
Signed-off-by: Hiroshi Shimamoto 
Tested-by: Hiroshi Shimamoto 
Cc: Trond Myklebust 
Fixes: 9130b8dbc6ac ("SUNRPC: allow for upcalls for same uid but different gss service")
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

NFSD: prevent integer overflow on 32 bit systems

2022-04-15T12:14:39+00:00

commit 23a9dbbe0faf124fc4c139615633b9d12a3a89ef upstream.

On a 32 bit system, the "len * sizeof(*p)" operation can have an
integer overflow.

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter 
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

SUNRPC/nfs: Fix return value for nfs4_callback_compound()

2021-09-22T09:47:47+00:00

commit 83dd59a0b9afc3b1a2642fb5c9b0585b1c08768f upstream.

RPC server procedures are normally expected to return a __be32 encoded
status value of type 'enum rpc_accept_stat', however at least one function
wants to return an authentication status of type 'enum rpc_auth_stat'
in the case where authentication fails.
This patch adds functionality to allow this.

Fixes: a4e187d83d88 ("NFS: Don't drop CB requests with invalid principals")
Signed-off-by: Trond Myklebust 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Move simple_get_bytes and simple_get_netobj into private header

2021-02-13T12:51:14+00:00

[ Upstream commit ba6dfce47c4d002d96cd02a304132fca76981172 ]

Remove duplicated helper functions to parse opaque XDR objects
and place inside new file net/sunrpc/auth_gss/auth_gss_internal.h.
In the new file carry the license and copyright from the source file
net/sunrpc/auth_gss/auth_gss.c.  Finally, update the comment inside
include/linux/sunrpc/xdr.h since lockd is not the only user of
struct xdr_netobj.

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

SUNRPC: xprt_load_transport() needs to support the netid "rdma6"

2020-12-30T10:25:59+00:00

[ Upstream commit d5aa6b22e2258f05317313ecc02efbb988ed6d38 ]

According to RFC5666, the correct netid for an IPv6 addressed RDMA
transport is "rdma6", which we've supported as a mount option since
Linux-4.7. The problem is when we try to load the module "xprtrdma6",
that will fail, since there is no modulealias of that name.

Fixes: 181342c5ebe8 ("xprtrdma: Add rdma6 option to support NFS/RDMA IPv6")
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

sunrpc: clean up properly in gss_mech_unregister()

2020-06-22T07:05:29+00:00

commit 24c5efe41c29ee3e55bcf5a1c9f61ca8709622e8 upstream.

gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each
flavour, but gss_mech_unregister() does not call auth_domain_put().
This is unbalanced and makes it impossible to reload the module.

Change svcauth_gss_register_pseudoflavor() to return the registered
auth_domain, and save it for later release.

Cc: stable@vger.kernel.org (v2.6.12+)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651
Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

svcrdma: Fix leak of svc_rdma_recv_ctxt objects

2020-05-02T15:25:52+00:00

commit 23cf1ee1f1869966b75518c59b5cbda4c6c92450 upstream.

Utilize the xpo_release_rqst transport method to ensure that each
rqstp's svc_rdma_recv_ctxt object is released even when the server
cannot return a Reply for that rqstp.

Without this fix, each RPC whose Reply cannot be sent leaks one
svc_rdma_recv_ctxt. This is a 2.5KB structure, a 4KB DMA-mapped
Receive buffer, and any pages that might be part of the Reply
message.

The leak is infrequent unless the network fabric is unreliable or
Kerberos is in use, as GSS sequence window overruns, which result
in connection loss, are more common on fast transports.

Fixes: 3a88092ee319 ("svcrdma: Preserve Receive buffer until svc_rdma_sendto")
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix priority queue fairness

2019-11-24T07:19:24+00:00

[ Upstream commit f42f7c283078ce3c1e8368b140e270755b1ae313 ]

Fix up the priority queue to not batch by owner, but by queue, so that
we allow '1 << priority' elements to be dequeued before switching to
the next priority queue.
The owner field is still used to wake up requests in round robin order
by owner to avoid single processes hogging the RPC layer by loading the
queues.

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

SUNRPC: Clean up initialisation of the struct rpc_rqst

2019-07-03T11:14:46+00:00

commit 9dc6edcf676fe188430e8b119f91280bbf285163 upstream.

Move the initialisation back into xprt.c.

Signed-off-by: Trond Myklebust 
Cc: Yihao Wu 
Cc: Caspar Zhang 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Always drop the XPRT_LOCK on XPRT_CLOSE_WAIT

2019-02-15T07:10:13+00:00

This patch is only appropriate for stable kernels v4.16 - v4.19

Since commit 9b30889c548a ("SUNRPC: Ensure we always close the socket after
a connection shuts down"), and until commit c544577daddb ("SUNRPC: Clean up
transport write space handling"), it is possible for the NFS client to spin
in the following tight loop:

269.964083: rpc_task_run_action: task:43@0 flags=5a81 state=0005 status=0 action=call_bind [sunrpc]
269.964083: rpc_task_run_action: task:43@0 flags=5a81 state=0005 status=0 action=call_connect [sunrpc]
269.964083: rpc_task_run_action: task:43@0 flags=5a81 state=0005 status=0 action=call_transmit [sunrpc]
269.964085: xprt_transmit: peer=[10.0.1.82]:2049 xid=0x761d3f77 status=-32
269.964085: rpc_task_run_action: task:43@0 flags=5a81 state=0005 status=-32 action=call_transmit_status [sunrpc]
269.964085: rpc_task_run_action: task:43@0 flags=5a81 state=0005 status=-32 action=call_status [sunrpc]
269.964085: rpc_call_status: task:43@0 status=-32

The issue is that the path through call_transmit_status does not release
the XPRT_LOCK when the transmit result is -EPIPE, so the socket cannot be
properly shut down.

The below commit fixed things up in mainline by unconditionally calling
xprt_end_transmit() and releasing the XPRT_LOCK after every pass through
call_transmit.  However, the entirety of this commit is not appropriate for
stable kernels because its original inclusion was part of a series that
modifies the sunrpc code to use a different queueing model.  As a result,
there are machinations within this patch that are not needed for a stable
fix and will not make sense without a larger backport of the mainline
series.

In this patch, we take the slightly modified bit of the mainline patch
below, which is to release the XPRT_LOCK on transmission error should we
detect that the transport is waiting to close.

commit c544577daddb618c7dd5fa7fb98d6a41782f020e upstream
Author: Trond Myklebust 
Date:   Mon Sep 3 23:39:27 2018 -0400

    SUNRPC: Clean up transport write space handling

    Treat socket write space handling in the same way we now treat transport
    congestion: by denying the XPRT_LOCK until the transport signals that it
    has free buffer space.

    Signed-off-by: Trond Myklebust 

The original discussion of the problem is here:

    https://lore.kernel.org/linux-nfs/20181212135157.4489-1-dwysocha@redhat.com/T/#t

This passes my usual cthon and xfstests on NFS as applied on v4.19 mainline.

Reported-by: Dave Wysochanski 
Suggested-by: Trond Myklebust 
Signed-off-by: Benjamin Coddington 
Signed-off-by: Greg Kroah-Hartman