A common exploit pattern for ROP attacks is to abuse prepare_kernel_cred()
in order to construct escalated privileges[1]. Instead of providing a
short-hand argument (NULL) to the "daemon" argument to indicate using
init_cred as the base cred, require that "daemon" is always set to
an actual task. Replace all existing callers that were passing NULL
with &init_task.
Future attacks will need to have sufficiently powerful read/write
primitives to have found an appropriately privileged task and written it
to the ROP stack as an argument to succeed, which is similarly difficult
to the prior effort needed to escalate privileges before struct cred
existed: locate the current cred and overwrite the uid member.
This has the added benefit of meaning that prepare_kernel_cred() can no
longer exceed the privileges of the init task, which may have changed from
the original init_cred (e.g. dropping capabilities from the bounding set).
[1] https://google.com/search?q=commit_creds(prepare_kernel_cred(0))
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steve French <sfrench@samba.org>
Cc: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: linux-nfs@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Russ Weight <russell.h.weight@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Link: https://lore.kernel.org/r/20221026232943.never.775-kees@kernel.org
If the layout is recalled or revoked, we want to cancel I/O as quickly
as possible so that we can return the layout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We want to ensure that the server never misses the layout stats when
we're closing the file, so that it knows whether or not to update its
internal state. Otherwise, if we were racing with a layout stat, we
might cause the server to invalidate its layout before the layout stat
got processed.
Fixes: 06946c6a3d ("pNFS/flexfiles: Only send layoutstats updates for mirrors that were updated")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Previously, we required this to value to be a power of 2 for UDP related
reasons. This patch keeps the power of 2 rule for UDP but allows more
flexibility for TCP and RDMA.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The RPC/RDMA driver will return -EPROTO and -ENODEV as connection errors
under certain circumstances. Make sure that we handle them and report
them to the server. If not, we can end up cycling forever in a
LAYOUTGET/LAYOUTRETURN loop.
Fixes: a12f996d34 ("NFSv4/pNFS: Use connections to a DS that are all of the same protocol family")
Cc: stable@vger.kernel.org # 5.11.x
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that pNFS flexfile allocations in rpciod/nfsiod callbacks can
fail in low memory mode, so that the threads don't block and loop
forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Assume that the higher layers will have set memalloc_nofs_save/restore
as appropriate.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
_nfs4_pnfs_v3/v4_ds_connect do
some work
smp_wmb
ds->ds_clp = clp;
And nfs4_ff_layout_prepare_ds currently does
smp_rmb
if(ds->ds_clp)
...
This patch places the smp_rmb after the if. This ensures that following
reads only happen once nfs4_ff_layout_prepare_ds has checked that data
has been properly initialized.
Fixes: d67ae825a5 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We (adam zabrocki, alexander matrosov, alexander tereshkin, maksym
bazalii) observed the check:
if (fh->size > sizeof(struct nfs_fh))
should not use the size of the nfs_fh struct which includes an extra two
bytes from the size field.
struct nfs_fh {
unsigned short size;
unsigned char data[NFS_MAXFHSIZE];
}
but should determine the size from data[NFS_MAXFHSIZE] so the memcpy
will not write 2 bytes beyond destination. The proposed fix is to
compare against the NFS_MAXFHSIZE directly, as is done elsewhere in fs
code base.
Fixes: d67ae825a5 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Nikola Livic <nlivic@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Highlights include:
Features:
- NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
support.
- A series of patches to improve readdir performance, particularly with
large directories.
- Basic support for using NFS/RDMA with the pNFS files and flexfiles
drivers.
- Micro-optimisations for RDMA.
- RDMA tracing improvements.
Bugfixes:
- Fix a long standing bug with xs_read_xdr_buf() when receiving partial
pages (Dan Aloni).
- Various fixes for getxattr and listxattr, when used over non-TCP
transports.
- Fixes for containerised NFS from Sargun Dhillon.
- switch nfsiod to be an UNBOUND workqueue (Neil Brown).
- READDIR should not ask for security label information if there is no
LSM policy. (Olga Kornievskaia)
- Avoid using interval-based rebinding with TCP in lockd (Calum Mackay).
- A series of RPC and NFS layer fixes to support the NFSv4.2 READ_PLUS code.
- A couple of fixes for pnfs/flexfiles read failover
Cleanups:
- Various cleanups for the SUNRPC xdr code in conjunction with the
READ_PLUS fixes.
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Merge tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Features:
- NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
support
- A series of patches to improve readdir performance, particularly
with large directories
- Basic support for using NFS/RDMA with the pNFS files and flexfiles
drivers
- Micro-optimisations for RDMA
- RDMA tracing improvements
Bugfixes:
- Fix a long standing bug with xs_read_xdr_buf() when receiving
partial pages (Dan Aloni)
- Various fixes for getxattr and listxattr, when used over non-TCP
transports
- Fixes for containerised NFS from Sargun Dhillon
- switch nfsiod to be an UNBOUND workqueue (Neil Brown)
- READDIR should not ask for security label information if there is
no LSM policy (Olga Kornievskaia)
- Avoid using interval-based rebinding with TCP in lockd (Calum
Mackay)
- A series of RPC and NFS layer fixes to support the NFSv4.2
READ_PLUS code
- A couple of fixes for pnfs/flexfiles read failover
Cleanups:
- Various cleanups for the SUNRPC xdr code in conjunction with the
READ_PLUS fixes"
* tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (90 commits)
NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()
pNFS/flexfiles: Avoid spurious layout returns in ff_layout_choose_ds_for_read
NFSv4/pnfs: Add tracing for the deviceid cache
fs/lockd: convert comma to semicolon
NFSv4.2: fix error return on memory allocation failure
NFSv4.2/pnfs: Don't use READ_PLUS with pNFS yet
NFSv4.2: Deal with potential READ_PLUS data extent buffer overflow
NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
NFSv4.2: Handle hole lengths that exceed the READ_PLUS read buffer
NFSv4.2: decode_read_plus_hole() needs to check the extent offset
NFSv4.2: decode_read_plus_data() must skip padding after data segment
NFSv4.2: Ensure we always reset the result->count in decode_read_plus()
SUNRPC: When expanding the buffer, we may need grow the sparse pages
SUNRPC: Cleanup - constify a number of xdr_buf helpers
SUNRPC: Clean up open coded setting of the xdr_stream 'nwords' field
SUNRPC: _copy_to/from_pages() now check for zero length
SUNRPC: Cleanup xdr_shrink_bufhead()
SUNRPC: Fix xdr_expand_hole()
SUNRPC: Fixes for xdr_align_data()
SUNRPC: _shift_data_left/right_pages should check the shift length
...
The callers of ff_layout_choose_ds_for_read() should decide whether or
not they want to return the layout on error. Sometimes, we may just want
to retry from the beginning.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
- Improve support for re-exporting NFS mounts
- Replace NFSv4 XDR decoding C macros with xdr_stream helpers
- Support for multiple RPC/RDMA chunks per RPC transaction
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Merge tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6
Pull nfsd updates from Chuck Lever:
"Several substantial changes this time around:
- Previously, exporting an NFS mount via NFSD was considered to be an
unsupported feature. With v5.11, the community has attempted to
make re-exporting a first-class feature of NFSD.
This would enable the Linux in-kernel NFS server to be used as an
intermediate cache for a remotely-located primary NFS server, for
example, even with other NFS server implementations, like a NetApp
filer, as the primary.
- A short series of patches brings support for multiple RPC/RDMA data
chunks per RPC transaction to the Linux NFS server's RPC/RDMA
transport implementation.
This is a part of the RPC/RDMA spec that the other premiere
NFS/RDMA implementation (Solaris) has had for a very long time, and
completes the implementation of RPC/RDMA version 1 in the Linux
kernel's NFS server.
- Long ago, NFSv4 support was introduced to NFSD using a series of C
macros that hid dprintk's and goto's. Over time, the kernel's XDR
implementation has been greatly improved, but these C macros have
remained and become fallow. A series of patches in this pull
request completely replaces those macros with the use of current
kernel XDR infrastructure. Benefits include:
- More robust input sanitization in NFSD's NFSv4 XDR decoders.
- Make it easier to use common kernel library functions that use
XDR stream APIs (for example, GSS-API).
- Align the structure of the source code with the RFCs so it is
easier to learn, verify, and maintain our XDR implementation.
- Removal of more than a hundred hidden dprintk() call sites.
- Removal of some explicit manipulation of pages to help make the
eventual transition to xdr->bvec smoother.
- On top of several related fixes in 5.10-rc, there are a few more
fixes to get the Linux NFSD implementation of NFSv4.2 inter-server
copy up to speed.
And as usual, there is a pinch of seasoning in the form of a
collection of unrelated minor bug fixes and clean-ups.
Many thanks to all who contributed this time around!"
* tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6: (131 commits)
nfsd: Record NFSv4 pre/post-op attributes as non-atomic
nfsd: Set PF_LOCAL_THROTTLE on local filesystems only
nfsd: Fix up nfsd to ensure that timeout errors don't result in ESTALE
exportfs: Add a function to return the raw output from fh_to_dentry()
nfsd: close cached files prior to a REMOVE or RENAME that would replace target
nfsd: allow filesystems to opt out of subtree checking
nfsd: add a new EXPORT_OP_NOWCC flag to struct export_operations
Revert "nfsd4: support change_attr_type attribute"
nfsd4: don't query change attribute in v2/v3 case
nfsd: minor nfsd4_change_attribute cleanup
nfsd: simplify nfsd4_change_info
nfsd: only call inode_query_iversion in the I_VERSION case
nfs_common: need lock during iterate through the list
NFSD: Fix 5 seconds delay when doing inter server copy
NFSD: Fix sparse warning in nfs4proc.c
SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall
sunrpc: clean-up cache downcall
nfsd: Fix message level for normal termination
NFSD: Remove macros that are no longer used
NFSD: Replace READ* macros in nfsd4_decode_compound()
...
Ensure that we report the correct netid when using UDP or RDMA
transports to the DSes.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the flexfiles mirroring is enabled, then the read code expects to be
able to set pgio->pg_mirror_idx to point to the data server that is
being used for this particular read. However it does not change the
pg_mirror_count because we only need to send a single read.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
While it is true that reading from an unmirrored source always uses
index 0, that is no longer true for mirrored sources when we fail over.
Fixes: 563c53e73b ("NFS: Fix flexfiles read failover")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The current mirrored read failover code is correctly resetting the mirror
index between failed reads, however it is not able to actually flip the
RPC call over to the next RPC client.
The end result is that we keep resending the RPC call to the same client
over and over.
The fix is to use the pnfs_read_resend_pnfs() mechanism to schedule a
new RPC call, but we need to add the ability to pass in a mirror
index so that we always retry the next mirror in the list.
Fixes: 166bd5b889 ("pNFS/flexfiles: Fix layoutstats handling during read failovers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Make sure we specify the layout segment range when calculating the
mirror count. In theory, that number could depend on the range to
which we're writing.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Both nfs_pageio_reset_read_mds() and nfs_pageio_reset_write_mds()
do call pnfs_generic_pg_cleanup() for us.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the mirror count changes in the new layout we pick up inside
ff_layout_pg_init_write(), then we can end up adding the
request to the wrong mirror and corrupting the mirror->pg_list.
Fixes: d600ad1f2b ("NFS41: pop some layoutget errors to application")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Move from requesting only full file layout segments, to requesting
layout segments that match our I/O size. This means the server is
still free to return a full file layout, but we will no longer
error out if it does not.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When starting to read or write with a layout segment, check that the
range matches our request.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Check that the number of mirrors, and the mirror information matches
before deciding to merge layout segments in pNFS/flexfiles.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Move the pNFS commit related operations into a separate structure
that can be carried by the pnfs_ds_commit_info.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Enable adding and lookup of per-layout segment commits in filelayout
and flexfilelayout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that both the file and flexfiles layout types clean up when
freeing the layout segments.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Just allocate the array at the end of the layout segment structure,
instead of allocating it as a separate array of pointers.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Ensure that if the DS is returning too many DELAY and GRACE errors, we
also report that to the MDS through the layouterror mechanism.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
If the attempt to do pNFS fails, then record what action we
take to recover (resend, reset to pnfs or reset to mds).
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the mount is hard, we should ignore the 'io_maxretrans' module
parameter so that we always keep retrying.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This reverts commit a79f194aa4.
The mechanism for aborting I/O is racy, since we are not guaranteed that
the request is asleep while we're changing both task->tk_status and
task->tk_action.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v5.1
Add tracepoints to allow debugging of the event chain leading to
a pnfs fallback to doing I/O through the MDS.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
mirror->mirror_ds can be NULL if uninitialised, but can contain
a PTR_ERR() if call to GETDEVICEINFO failed.
Fixes: 65990d1afb ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # 4.10+
Fix a typo where we're confusing the default TCP retrans value
(NFS_DEF_TCP_RETRANS) for the default TCP timeout value.
Fixes: 15d03055cf ("pNFS/flexfiles: Set reasonable default ...")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a helper for when we remove the explicit pointer to the open
context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
During a read failover, we may end up changing the value of
the pgio_mirror_idx, so make sure that we record the layout
stats before that update.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Get rid of the redundant parameter and rename the function
ff_layout_mirror_valid() to ff_layout_init_mirror_ds() for clarity.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
nfs4_ff_alloc_deviceid_node() guarantees that if mirror->mirror_ds is
a valid pointer, then so is mirror->mirror_ds->ds.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
