The encryption subkeys are not used after the cipher transforms have
been allocated and keyed. There is no need to retain them in struct
krb5_ctx.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Hoist the name of the aux_cipher into struct gss_krb5_enctype to
prepare for obscuring the encryption keys just after they are
derived.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
ctx->Ksess is never used after import has completed. Obscure it
immediately so it cannot be re-used or copied.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Other common Kerberos implementations use a fully random confounder
for encryption. The reason for this is explained in the new comment
added by this patch. The current get_random_bytes() implementation
does not exhaust system entropy.
Since confounder generation is part of Kerberos itself rather than
the GSS-API Kerberos mechanism, the function is renamed and moved.
Note that light top-down analysis shows that the SHA-1 transform
is by far the most CPU-intensive part of encryption. Thus we do not
expect this change to result in a significant performance impact.
However, eventually it might be necessary to generate an independent
stream of confounders for each Kerberos context to help improve I/O
parallelism.
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that arcfour-hmac is gone, the confounder length is again the
same as the cipher blocksize for every implemented enctype. The
gss_krb5_enctype::conflen field is no longer necessary.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It is not clear from documenting comments, specifications, or code
usage what value the gss_krb5_enctype.blocksize field is supposed
to store. The "encryption blocksize" depends only on the cipher
being used, so that value can be derived where it's needed instead
of stored as a constant.
RFC 3961 Section 5.2 says:
> cipher block size, c
> This is the block size of the block cipher underlying the
> encryption and decryption functions indicated above, used for key
> derivation and for the size of the message confounder and initial
> vector. (If a block cipher is not in use, some comparable
> parameter should be determined.) It must be at least 5 octets.
>
> This is not actually an independent parameter; rather, it is a
> property of the functions E and D. It is listed here to clarify
> the distinction between it and the message block size, m.
In the Linux kernel's implemenation of the SunRPC RPCSEC GSS
Kerberos 5 mechanism, the cipher block size, which is dependent on
the encryption and decryption transforms, is used only in
krb5_derive_key(), so it is straightforward to replace it.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that svcauth_gss_prepare_to_wrap() no longer computes the
location of RPC header fields in the response buffer,
svcauth_gss_accept() can save the location of the databody
rather than the location of the verifier.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
To navigate around the space that svcauth_gss_accept() reserves
for the RPC payload body length and sequence number fields,
svcauth_gss_release() does a little dance with the reply's
accept_stat, moving the accept_stat value in the response buffer
down by two words.
Instead, let's have the ->accept() methods each set the proper
final location of the accept_stat to avoid having to move
things.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that each ->accept method has been converted, the
svcxdr_init_encode() calls can be hoisted back up into the generic
RPC server code.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header encoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This code constructs replies to the decorated NULL procedure calls
that establish GSS contexts. Convert this code path to use struct
xdr_stream to encode such responses.
Done as part of hardening the server-side RPC header encoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We're now moving svcxdr_init_encode() to /before/ the flavor's
->accept method has set rq_auth_slack. Add a helper that can
set rq_auth_slack /after/ svcxdr_init_encode() has been called.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: So that the overhaul of each ->accept method can be done
in separate smaller patches, temporarily move the
svcxdr_init_encode() call into those methods.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit 5b304bc5bf ("[PATCH] knfsd: svcrpc: gss: fix failure on
SVC_DENIED in integrity case") added a check to prevent wrapping an
RPC response if reply_stat == MSG_DENIED, assuming that the only way
to get to svcauth_gss_release() with that reply_stat value was if
the reject_stat was AUTH_ERROR (reject_stat == MISMATCH is handled
earlier in svc_process_common()).
The code there is somewhat confusing. For one thing, rpc_success is
an accept_stat value, not a reply_stat value. The correct reply_stat
value to look for is RPC_MSG_DENIED. It happens to be the same value
as rpc_success, so it all works out, but it's not terribly readable.
Since commit 438623a06b ("SUNRPC: Add svc_rqst::rq_auth_stat"),
the actual auth_stat value is stored in the svc_rqst, so that value
is now available to svcauth_gss_prepare_to_wrap() to make its
decision to wrap, based on direct information about the
authentication status of the RPC caller.
No behavior change is intended, this simply replaces some old code
with something that should be more self-documenting.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Actually xdr_stream does not add value here because of how
gss_wrap() works. This is just a clean-up patch.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Simplify the references to the head and tail iovecs for readability.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Match the error reporting in the other unwrap and wrap functions.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up variable names to match the other unwrap and wrap
functions.
Additionally, the explicit type cast on @gsd in unnecessary; and
@resbuf is renamed to match the variable naming in the unwrap
functions.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Replace finicky logic: Instead of trying to find scratch space in
the response buffer, use the scratch buffer from struct
gss_svc_data.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: To help orient readers, name the stack variables to match
the XDR field names.
Additionally, the explicit type cast on @gsd is unnecessary; and
@resbuf is renamed to match the variable naming in the unwrap
functions.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that upper layers use an xdr_stream to track the construction
of each RPC Reply message, resbuf->len is kept up-to-date
automatically. There's no need to recompute it in svc_gss_release().
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that each ->accept method has been converted to use xdr_stream,
the svcxdr_init_decode() calls can be hoisted back up into the
generic RPC server code.
The dprintk in svc_authenticate() is removed, since
trace_svc_authenticate() reports the same information.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Micro-optimizations:
1. The value of rqstp->rq_auth_stat is replaced no matter which
arm of the switch is taken, so the initial assignment can be
safely removed.
2. Avoid checking the value of gc->gc_proc twice in the I/O
(RPC_GSS_PROC_DATA) path.
The cost is a little extra code redundancy.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: To help orient readers, name the stack variables to match
the XDR field names.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: To help orient readers, name the stack variables to match
the XDR field names.
For readability, I'm also going to rename the unwrap and wrap
functions in a consistent manner, starting with unwrap_integ_data().
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up / code de-duplication - this functionality is already
available in the generic XDR layer.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The entire RPC_GSS_PROC_INIT path is converted over to xdr_stream
for decoding the Call credential and verifier.
Done as part of hardening the server-side RPC header decoding path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
gss_read_verf() is already short. Fold it into its only caller.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
gss_read_common_verf() is now just a wrapper for dup_netobj(), thus
it can be replaced with direct calls to dup_netobj().
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since upcalls are infrequent, ensure the compiler places the upcall
mechanism out-of-line from the I/O path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: So that the overhaul of each ->accept method can be done
in separate smaller patches, temporarily move the
svcxdr_init_decode() call into those methods.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull nfsd fixes from Chuck Lever:
- Fix a race when creating NFSv4 files
- Revert the use of relaxed bitops
* tag 'nfsd-6.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: Use set_bit(RQ_DROPME)
Revert "SUNRPC: Use RMW bitops in single-threaded hot paths"
nfsd: fix handling of cached open files in nfsd4_open codepath
Pull NFS client fixes from Trond Myklebust:
- Fix a race in the RPCSEC_GSS upcall code that causes hung RPC calls
- Fix a broken coalescing test in the pNFS file layout driver
- Ensure that the access cache rcu path also applies the login test
- Fix up for a sparse warning
* tag 'nfs-for-6.2-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Fix up a sparse warning
NFS: Judge the file access cache's timestamp in rcu path
pNFS/filelayout: Fix coalescing test for single DS
SUNRPC: ensure the matching upcall is in-flight upon downcall
The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.
Found via KCSAN.
Fixes: 28df098881 ("SUNRPC: Use RMW bitops in single-threaded hot paths")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit 9130b8dbc6 ("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 <minoura@valinux.co.jp>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@nec.com>
Tested-by: Hiroshi Shimamoto <h-shimamoto@nec.com>
Cc: Trond Myklebust <trondmy@hammerspace.com>
Fixes: 9130b8dbc6 ("SUNRPC: allow for upcalls for same uid but different gss service")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If a zero length is passed to kmalloc() it returns 0x10, which is
not a valid address. gss_verify_mic() subsequently crashes when it
attempts to dereference that pointer.
Instead of allocating this memory on every call based on an
untrusted size value, use a piece of dynamically-allocated scratch
memory that is always available.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
If a zero length is passed to kmalloc() it returns 0x10, which is
not a valid address. gss_unwrap_resp_integ() subsequently crashes
when it attempts to dereference that pointer.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Use the standard gfp mask instead of using GFP_NOWAIT. The latter causes
issues when under memory pressure.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
I noticed CPU pipeline stalls while using perf.
Once an svc thread is scheduled and executing an RPC, no other
processes will touch svc_rqst::rq_flags. Thus bus-locked atomics are
not needed outside the svc thread scheduler.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure that the gssproxy client connects to the server from the gssproxy
daemon process context so that the AF_LOCAL socket connection is done
using the correct path and namespaces.
Fixes: 1d658336b0 ("SUNRPC: Add RPC based upcall mechanism for RPCGSS auth")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This reverts commit 892de36fd4.
The gssproxy server is unresponsive when it calls into the kernel to
start the upcall service, so it will not reply to our RPC ping at all.
Reported-by: "J.Bruce Fields" <bfields@fieldses.org>
Fixes: 892de36fd4 ("SUNRPC: Ensure gss-proxy connects on setup")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
