linux/fs/nfsd
J. Bruce Fields 9a307403d3 nfsd4: fix null dereference on replay
if we receive a compound such that:

	- the sessionid, slot, and sequence number in the SEQUENCE op
	  match a cached succesful reply with N ops, and
	- the Nth operation of the compound is a PUTFH, PUTPUBFH,
	  PUTROOTFH, or RESTOREFH,

then nfsd4_sequence will return 0 and set cstate->status to
nfserr_replay_cache.  The current filehandle will not be set.  This will
cause us to call check_nfsd_access with first argument NULL.

To nfsd4_compound it looks like we just succesfully executed an
operation that set a filehandle, but the current filehandle is not set.

Fix this by moving the nfserr_replay_cache earlier.  There was never any
reason to have it after the encode_op label, since the only case where
he hit that is when opdesc->op_func sets it.

Note that there are two ways we could hit this case:

	- a client is resending a previously sent compound that ended
	  with one of the four PUTFH-like operations, or
	- a client is sending a *new* compound that (incorrectly) shares
	  sessionid, slot, and sequence number with a previously sent
	  compound, and the length of the previously sent compound
	  happens to match the position of a PUTFH-like operation in the
	  new compound.

The second is obviously incorrect client behavior.  The first is also
very strange--the only purpose of a PUTFH-like operation is to set the
current filehandle to be used by the following operation, so there's no
point in having it as the last in a compound.

So it's likely this requires a buggy or malicious client to reproduce.

Reported-by: Scott Mayhew <smayhew@redhat.com>
Cc: stable@kernel.vger.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-05-23 14:20:58 -04:00
..
acl.h nfsd4: remove nfs4_acl_new 2014-07-08 17:14:27 -04:00
auth.c cred: simpler, 1D supplementary groups 2016-10-07 18:46:30 -07:00
auth.h
blocklayout.c scsi: introduce a result field in struct scsi_request 2017-04-20 12:16:10 -06:00
blocklayoutxdr.c Highlights: 2016-08-04 19:59:06 -04:00
blocklayoutxdr.h nfsd: add SCSI layout support 2016-03-18 11:42:53 -04:00
cache.h nfsd: Remove the cache_hash list 2014-08-17 12:00:12 -04:00
current_stateid.h
export.c nfsd: opt in to labeled nfs per export 2017-01-31 12:31:54 -05:00
export.h nfsd: allow nfsd to advertise multiple layout types 2016-07-15 15:31:32 -04:00
fault_inject.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
flexfilelayout.c nfsd: don't set a FL_LAYOUT lease for flexfiles layouts 2016-09-16 16:15:52 -04:00
flexfilelayoutxdr.c nfsd: Add a super simple flex file server 2016-07-13 15:40:48 -04:00
flexfilelayoutxdr.h nfsd: Add a super simple flex file server 2016-07-13 15:40:48 -04:00
idmap.h nfsd: Remove duplicate define of IDMAP_NAMESZ/IDMAP_TYPE_xx 2015-07-20 14:58:46 -04:00
Kconfig block: make scsi_request and scsi ioctl support optional 2017-01-31 10:53:05 -07:00
lockd.c lockd: constify nlmsvc_binding structure 2016-01-07 10:10:50 -05:00
Makefile nfsd: Add a super simple flex file server 2016-07-13 15:40:48 -04:00
netns.h netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
nfs2acl.c sunrpc: turn bitfield flags in svc_version into bools 2017-02-24 15:50:08 -05:00
nfs3acl.c sunrpc: turn bitfield flags in svc_version into bools 2017-02-24 15:50:08 -05:00
nfs3proc.c NFSD: cleanup dead codes and values in nfsd_write 2017-01-31 12:31:53 -05:00
nfs3xdr.c nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments" 2017-05-16 16:16:30 -04:00
nfs4acl.c nfsd: check permissions when setting ACLs 2016-06-24 12:11:52 -04:00
nfs4callback.c nfsd/callback: Drop a useless data copy when comparing sessionid 2017-02-17 16:26:02 -05:00
nfs4idmap.c nfsd/idmap: return nfserr_inval for 0-length names 2017-02-17 16:25:59 -05:00
nfs4layouts.c driver core patches for 4.11-rc1 2017-02-22 11:44:32 -08:00
nfs4proc.c nfsd4: fix null dereference on replay 2017-05-23 14:20:58 -04:00
nfs4recover.c Various bugfixes, a RDMA update from Chuck Lever, and support for a new 2016-03-24 10:41:00 -07:00
nfs4state.c nfsd4: remove pointless strdup_if_nonnull 2017-04-25 17:25:54 -04:00
nfs4xdr.c nfsd: Fix up the "supattr_exclcreat" attributes 2017-05-10 14:30:10 -04:00
nfscache.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
nfsctl.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
nfsd.h nfsd: constify nfsd_suppatttrs 2017-01-31 12:31:54 -05:00
nfsfh.c nfsd: check d_can_lookup in fh_verify of directories 2016-08-04 17:11:48 -04:00
nfsfh.h wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
nfsproc.c nfsd: map the ENOKEY to nfserr_perm for avoiding warning 2017-03-10 16:54:55 -05:00
nfssvc.c nfsd: check for oversized NFSv2/v3 arguments 2017-04-25 16:34:37 -04:00
nfsxdr.c nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments" 2017-05-16 16:16:30 -04:00
pnfs.h nfsd: don't set a FL_LAYOUT lease for flexfiles layouts 2016-09-16 16:15:52 -04:00
state.h nfsd/callback: Cleanup callback cred on shutdown 2017-02-17 16:26:00 -05:00
stats.c drop redundant ->owner initializations 2016-05-29 19:08:00 -04:00
stats.h nfsd: move <linux/nfsd/stats.h> to fs/nfsd 2014-05-06 17:54:55 -04:00
trace.c nfsd: move include of state.h from trace.c to trace.h 2015-10-23 15:57:29 -04:00
trace.h nfsd: add new io class tracepoint 2016-01-14 17:32:51 -05:00
vfs.c Another RDMA update from Chuck Lever, and a bunch of miscellaneous 2017-05-10 13:29:23 -07:00
vfs.h statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
xdr3.h nfsd: fix encode_entryplus_baggage stack usage 2014-01-23 13:50:27 -05:00
xdr4.h NFSD: Implement the COPY call 2016-10-07 14:54:25 -04:00
xdr4cb.h nfsd: plumb in a CB_NOTIFY_LOCK operation 2016-09-26 15:20:35 -04:00
xdr.h