rsc_lookup steals the passed-in memory to avoid doing an allocation of
its own, so we can't just pass in a pointer to memory that someone else
is using.

If we really want to avoid allocation there then maybe we should
preallocate somwhere, or reference count these handles.

For now we should revert.

On occasion I see this on my server:

kernel: kernel BUG at /home/cel/src/linux/linux-2.6/mm/slub.c:3851!
kernel: invalid opcode: 0000 [#1] SMP
kernel: Modules linked in: cts rpcsec_gss_krb5 sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd btrfs xor iTCO_wdt iTCO_vendor_support raid6_pq pcspkr i2c_i801 i2c_smbus lpc_ich mfd_core mei_me sg mei shpchp wmi ioatdma ipmi_si ipmi_msghandler acpi_pad acpi_power_meter rpcrdma ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd nfs_acl lockd grace auth_rpcgss sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb mlx4_core ahci libahci libata ptp pps_core dca i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
kernel: CPU: 7 PID: 145 Comm: kworker/7:2 Not tainted 4.8.0-rc4-00006-g9d06b0b #15
kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
kernel: Workqueue: events do_cache_clean [sunrpc]
kernel: task: ffff8808541d8000 task.stack: ffff880854344000
kernel: RIP: 0010:[<ffffffff811e7075>]  [<ffffffff811e7075>] kfree+0x155/0x180
kernel: RSP: 0018:ffff880854347d70  EFLAGS: 00010246
kernel: RAX: ffffea0020fe7660 RBX: ffff88083f9db064 RCX: 146ff0f9d5ec5600
kernel: RDX: 000077ff80000000 RSI: ffff880853f01500 RDI: ffff88083f9db064
kernel: RBP: ffff880854347d88 R08: ffff8808594ee000 R09: ffff88087fdd8780
kernel: R10: 0000000000000000 R11: ffffea0020fe76c0 R12: ffff880853f01500
kernel: R13: ffffffffa013cf76 R14: ffffffffa013cff0 R15: ffffffffa04253a0
kernel: FS:  0000000000000000(0000) GS:ffff88087fdc0000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fed60b020c3 CR3: 0000000001c06000 CR4: 00000000001406e0
kernel: Stack:
kernel: ffff8808589f2f00 ffff880853f01500 0000000000000001 ffff880854347da0
kernel: ffffffffa013cf76 ffff8808589f2f00 ffff880854347db8 ffffffffa013d006
kernel: ffff8808589f2f20 ffff880854347e00 ffffffffa0406f60 0000000057c7044f
kernel: Call Trace:
kernel: [<ffffffffa013cf76>] rsc_free+0x16/0x90 [auth_rpcgss]
kernel: [<ffffffffa013d006>] rsc_put+0x16/0x30 [auth_rpcgss]
kernel: [<ffffffffa0406f60>] cache_clean+0x2e0/0x300 [sunrpc]
kernel: [<ffffffffa04073ee>] do_cache_clean+0xe/0x70 [sunrpc]
kernel: [<ffffffff8109a70f>] process_one_work+0x1ff/0x3b0
kernel: [<ffffffff8109b15c>] worker_thread+0x2bc/0x4a0
kernel: [<ffffffff8109aea0>] ? rescuer_thread+0x3a0/0x3a0
kernel: [<ffffffff810a0ba4>] kthread+0xe4/0xf0
kernel: [<ffffffff8169c47f>] ret_from_fork+0x1f/0x40
kernel: [<ffffffff810a0ac0>] ? kthread_stop+0x110/0x110
kernel: Code: f7 ff ff eb 3b 65 8b 05 da 30 e2 7e 89 c0 48 0f a3 05 a0 38 b8 00 0f 92 c0 84 c0 0f 85 d1 fe ff ff 0f 1f 44 00 00 e9 f5 fe ff ff <0f> 0b 49 8b 03 31 f6 f6 c4 40 0f 85 62 ff ff ff e9 61 ff ff ff
kernel: RIP  [<ffffffff811e7075>] kfree+0x155/0x180
kernel: RSP <ffff880854347d70>
kernel: ---[ end trace 3fdec044969def26 ]---

It seems to be most common after a server reboot where a client has been
using a Kerberos mount, and reconnects to continue its workload.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

GSS-Proxy doesn't produce very much debug logging at all.  Printing out
the gss minor status will aid in troubleshooting if the
GSS_Accept_sec_context upcall fails.
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The length of the GSS MIC token need not be a multiple of four bytes.
It is then padded by XDR to a multiple of 4 B, but unwrap_integ_data()
would previously only trim mic.len + 4 B. The remaining up to three
bytes would then trigger a check in nfs4svc_decode_compoundargs(),
leading to a "garbage args" error and mount failure:

nfs4svc_decode_compoundargs: compound not properly padded!
nfsd: failed to decode arguments!

This would prevent older clients using the pre-RFC 4121 MIC format
(37-byte MIC including a 9-byte OID) from mounting exports from v3.9+
servers using krb5i.

The trimming was introduced by commit 4c190e2f ("sunrpc: trim off
trailing checksum before returning decrypted or integrity authenticated
buffer").

Fixes: 4c190e2f "unrpc: trim off trailing checksum..."
Signed-off-by: NTomáš Trnka <ttrnka@mail.muni.cz>
Cc: stable@vger.kernel.org
Acked-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Reported-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we call groups_alloc() with invalid values then it's might lead to
memory corruption.  For example, with a negative value then we might not
allocate enough for sizeof(struct group_info).

(We're doing this in the caller for consistency with other callers of
groups_alloc().  The other alternative might be to move the check out of
all the callers into groups_alloc().)
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NSimo Sorce <simo@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It's always set to whatever CONFIG_SUNRPC_DEBUG is, so just use that.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

rq_usedeferral and rq_splice_ok are used as 0 and 1, just defined to bool.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

RPC_MAX_AUTH_SIZE is scattered around several places.  Better to set it
once in the auth code, where this kind of estimate should be made.  And
while we're at it we can leave it zero when we're not using krb5i or
krb5p.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We can achieve the same result with a cmpxchg(). This also fixes a
potential race in use_gss_proxy(). The value of sn->use_gss_proxy could
go from -1 to 1 just after we check it in use_gss_proxy() but before we
acquire the spinlock. The procfile write would end up returning success
but the value would flip to 0 soon afterward. With this method we not
only avoid locking but the first "setter" always wins.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

An nfsd thread can call use_gss_proxy and find it set to '1' but find
gssp_clnt still NULL, so that when it attempts the upcall the result
will be an unnecessary -EIO.

So, ensure that gssp_clnt is created first, and set the use_gss_proxy
variable only if that succeeds.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It doesn't make much sense to make reads from this procfile hang. As
far as I can tell, only gssproxy itself will open this file and it
never reads from it. Change it to just give the present setting of
sn->use_gss_proxy without waiting for anything.

Note that we do not want to call use_gss_proxy() in this codepath
since an inopportune read of this file could cause it to be disabled
prematurely.

Cc: stable@vger.kernel.org
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For every other problem here we bail out with an error, but here for
some reason we're setting a negative cache entry (with, note, an
undefined expiry).

It seems simplest just to bail out in the same way as we do in other
cases.

Cc: Simo Sorce <simo@redhat.com>
Reported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The change made to rsc_parse() in
0dc1531a "svcrpc: store gss mech in
svc_cred" should also have been propagated to the gss-proxy codepath.
This fixes a crash in the gss-proxy case.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Store a pointer to the gss mechanism used in the rq_cred and cl_cred.
This will make it easier to enforce SP4_MACH_CRED, which needs to
compare the mechanism used on the exchange_id with that used on
protected operations.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Common helper to zero out fields of the svc_cred.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Somebody noticed LTP was complaining about O_NONBLOCK opens of
/proc/net/rpc/use-gss-proxy succeeding and then a following read
hanging.

I'm not convinced LTP really has any business opening random proc files
and expecting them to behave a certain way.  Maybe this isn't really a
bug.

But in any case the O_NONBLOCK behavior could be useful for someone that
wants to test whether gss-proxy is up without waiting.
Reported-by: NJan Stancek <jstancek@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This should return zero on success and -EBUSY on error so the type
needs to be int instead of bool.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Though I wonder whether we should really just depend on CONFIG_PROC_FS
at some point.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>

The main advantge of this new upcall mechanism is that it can handle
big tickets as seen in Kerberos implementations where tickets carry
authorization data like the MS-PAC buffer with AD or the Posix Authorization
Data being discussed in IETF on the krbwg working group.

The Gssproxy program is used to perform the accept_sec_context call on the
kernel's behalf. The code is changed to also pass the input buffer straight
to upcall mechanism to avoid allocating and copying many pages as tokens can
be as big (potentially more in future) as 64KiB.
Signed-off-by: NSimo Sorce <simo@redhat.com>
[bfields: containerization, negotiation api]
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We expose this parameter for a future caller.
It will be used to extract the endtime from the gss-proxy upcall mechanism,
in order to set the rsc cache expiration time.
Signed-off-by: NSimo Sorce <simo@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The NFSv4 SECINFO operation returns a list of security flavors that
the server supports for a particular share.  An NFSv4 client is
supposed to pick a pseudoflavor it supports that corresponds to one
of the flavors returned by the server.

GSS flavors in this list have a GSS tuple that identify a specific
GSS pseudoflavor.

Currently our client ignores the GSS tuple's "qop" value.  A
matching pseudoflavor is chosen based only on the OID and service
value.

So far this omission has not had much effect on Linux.  The NFSv4
protocol currently supports only one qop value: GSS_C_QOP_DEFAULT,
also known as zero.

However, if an NFSv4 server happens to return something other than
zero in the qop field, our client won't notice.  This could cause
the client to behave in incorrect ways that could have security
implications.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

krb5 mounts started failing as of
683428fa "sunrpc: Update svcgss xdr
handle to rpsec_contect cache".

The problem is that mounts are usually done with some host principal
which isn't normally mapped to any user, in which case svcgssd passes
down uid -1, which the kernel is then expected to map to the
export-specific anonymous uid or gid.

The new uid_valid/gid_valid checks were therefore causing that downcall
to fail.

(Note the regression may not have been seen with older userspace that
tended to map unknown principals to an anonymous id on their own rather
than leaving it to the kernel.)
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

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: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This callback will allow to simplify upcalls in further patches in this
series.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For each received uid call make_kuid and validate the result.
For each received gid call make_kgid and validate the result.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

When GSSAPI integrity signatures are in use, or when we're using GSSAPI
privacy with the v2 token format, there is a trailing checksum on the
xdr_buf that is returned.

It's checked during the authentication stage, and afterward nothing
cares about it. Ordinarily, it's not a problem since the XDR code
generally ignores it, but it will be when we try to compute a checksum
over the buffer to help prevent XID collisions in the duplicate reply
cache.

Fix the code to trim off the checksums after verifying them. Note that
in unwrap_integ_data, we must avoid trying to reverify the checksum if
the request was deferred since it will no longer be present when it's
revisited.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Move the rq_flavor into struct svc_cred, and use it in setclientid and
exchange_id comparisons as well.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Instead of keeping the principal name associated with a request in a
structure that's private to auth_gss and using an accessor function,
move it to svc_cred.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values.   Unless user namespaces are used this change should
have no effect.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

This is needed to share code between the current server upcall mechanism
and the new gssproxy upcall mechanism introduced in a following patch.
Signed-off-by: NSimo Sorce <simo@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This patch makes GSS auth cache details allocated and registered per network
namespace context.
Thus with this patch rsi_cache and rsc_cache contents for network namespace "X"
are controlled from proc file system mount for the same network namespace "X".
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

These macros never be used for several years.
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Code like:

  switch(xxx) {
  case -error1:
  case -error2:
     ..
     return;
  case 0:
     stuff;
  }

  can more naturally be written:

  if (xxx < 0)
      return;

  stuff;
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we drop a request in the sunrpc layer, either due kmalloc failure,
or due to a cache miss when we could not queue the request for later
replay, then close the connection to encourage the client to retry sooner.

Note that if the drop happens in the NFS layer, NFSERR_JUKEBOX
(aka NFS4ERR_DELAY) is returned to guide the client concerning
replay.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Again, we can deadlock if the memory reclaim triggers a writeback that
requires a rpcsec_gss credential lookup.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>