linux-stable.git/include/trace/events/sunrpc.h, branch linux-4.19.y

sunrpc: use-after-free in svc_process_common()

2019-01-16T21:04:37+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()
Signed-off-by: Vasily Averin 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'nfs-for-4.17-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

2018-05-11T20:56:43+00:00

Pull NFS client fixes from Anna Schumaker:
 "These patches fix both a possible corruption during NFSoRDMA MR
  recovery, and a sunrpc tracepoint crash.

  Additionally, Trond has a new email address to put in the MAINTAINERS
  file"

* tag 'nfs-for-4.17-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  Change Trond's email address in MAINTAINERS
  sunrpc: Fix latency trace point crashes
  xprtrdma: Fix list corruption / DMAR errors during MR recovery

sunrpc: Fix latency trace point crashes

2018-05-01T17:46:14+00:00

If the rpc_task survived longer than the transport, task->tk_xprt
points to freed memory by the time rpc_count_iostats_metrics runs.
Replace the references to task->tk_xprt with references to the
task's tk_client.

Reported-by: syzbot+27db1f90e2b972a5f2d3@syzkaller.appspotmail.com
Fixes: 40bf7eb304b5 ('sunrpc: Add static trace point to report ...')
Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker

Merge tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2018-04-12T19:55:50+00:00

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - xprtrdma: Fix corner cases when handling device removal # v4.12+
   - xprtrdma: Fix latency regression on NUMA NFS/RDMA clients # v4.15+

  Features:
   - New sunrpc tracepoint for RPC pings
   - Finer grained NFSv4 attribute checking
   - Don't unnecessarily return NFS v4 delegations

  Other bugfixes and cleanups:
   - Several other small NFSoRDMA cleanups
   - Improvements to the sunrpc RTT measurements
   - A few sunrpc tracepoint cleanups
   - Various fixes for NFS v4 lock notifications
   - Various sunrpc and NFS v4 XDR encoding cleanups
   - Switch to the ida_simple API
   - Fix NFSv4.1 exclusive create
   - Forget acl cache after setattr operation
   - Don't advance the nfs_entry readdir cookie if xdr decoding fails"

* tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (47 commits)
  NFS: advance nfs_entry cookie only after decoding completes successfully
  NFSv3/acl: forget acl cache after setattr
  NFSv4.1: Fix exclusive create
  NFSv4: Declare the size up to date after it was set.
  nfs: Use ida_simple API
  NFSv4: Fix the nfs_inode_set_delegation() arguments
  NFSv4: Clean up CB_GETATTR encoding
  NFSv4: Don't ask for attributes when ACCESS is protected by a delegation
  NFSv4: Add a helper to encode/decode struct timespec
  NFSv4: Clean up encode_attrs
  NFSv4; Clean up XDR encoding of type bitmap4
  NFSv4: Allow GFP_NOIO sleeps in decode_attr_owner/decode_attr_group
  SUNRPC: Add a helper for encoding opaque data inline
  SUNRPC: Add helpers for decoding opaque and string types
  NFSv4: Ignore change attribute invalidations if we hold a delegation
  NFS: More fine grained attribute tracking
  NFS: Don't force unnecessary cache invalidation in nfs_update_inode()
  NFS: Don't redirty the attribute cache in nfs_wcc_update_inode()
  NFS: Don't force a revalidation of all attributes if change is missing
  NFS: Convert NFS_INO_INVALID flags to unsigned long
  ...

sunrpc: Add static trace point to report result of RPC ping

2018-04-10T20:06:22+00:00

This information can help track down local misconfiguration issues
as well as network partitions and unresponsive servers.

There are several ways to send a ping, and with transport multi-
plexing, the exact rpc_xprt that is used is sometimes not known by
the upper layer. The rpc_xprt pointer passed to the trace point
call also has to be RCU-safe.

I found a spot inside the client FSM where an rpc_xprt pointer is
always available and safe to use.

Suggested-by: Bill Baker 
Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker

sunrpc: Add static trace point to report RPC latency stats

2018-04-10T20:06:22+00:00

Introduce a low-overhead mechanism to report information about
latencies of individual RPCs. The goal is to enable user space to
filter the trace record for latency outliers, or build histograms,
etc.

Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker

sunrpc: Simplify synopsis of some trace points

2018-04-10T20:06:22+00:00

Clean up: struct rpc_task carries a pointer to a struct rpc_clnt,
and in fact task->tk_client is always what is passed into trace
points that are already passing @task.

Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker

svc: Report xprt dequeue latency

2018-04-03T19:08:13+00:00

Record the time between when a rqstp is enqueued on a transport
and when it is dequeued. This includes how long the rqstp waits on
the queue and how long it takes the kernel scheduler to wake a
nfsd thread to service it.

The svc_xprt_dequeue trace point is altered to include the number
of microseconds between xprt_enqueue and xprt_dequeue.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

sunrpc: Report per-RPC execution stats

2018-04-03T19:08:12+00:00

Introduce a mechanism to report the server-side execution latency of
each RPC. The goal is to enable user space to filter the trace
record for latency outliers, build histograms, etc.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

sunrpc: Re-purpose trace_svc_process

2018-04-03T19:08:12+00:00

Currently, trace_svc_process has two call sites:

1. Just after a call to svc_send. svc_send already invokes
   trace_svc_send with the same arguments just before returning

2. Just before a call to svc_drop. svc_drop already invokes
   trace_svc_drop with the same arguments just after it is called

Therefore trace_svc_process does not provide any additional
information not already provided by these other trace points.

However, it would be useful to record the incoming RPC procedure.
So reuse trace_svc_process for this purpose.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields