If the client requests a directory delegation with notifications
enabled, set the appropriate return mask in gddr_notification[0]. This
will ensure the lease acquisition sets the appropriate ignore mask.
Also store the granted mask in the delegation's dl_notify_mask field, so
that the CB_NOTIFY encoder can later tell which notifications the client
was granted.
If the client doesn't set NOTIFY4_GFLAG_EXTEND, then don't offer any
notifications, as nfsd won't provide directory offset information, and
"classic" notifications require them.
Similarly, if the client sets GFLAG_EXTEND | CFLAG_ORDER, then zero out
the notification mask. The Linux server can't provide the necessary
ordering info to those clients.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-11-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Add the necessary parts to accept a fsnotify callback for directory
change event and create a CB_NOTIFY request for it. When a dir nfsd_file
is created set a handle_event callback to handle the notification.
Use that to allocate a nfsd_notify_event object and then hand off a
reference to each delegation's CB_NOTIFY. If anything fails along the
way, recall any affected delegations.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-10-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Add the data structures, allocation helpers, and callback operations
needed for directory delegation CB_NOTIFY support:
- struct nfsd_notify_event: carries fsnotify events for CB_NOTIFY
- struct nfsd4_cb_notify: per-delegation state for notification handling
- Union dl_cb_fattr with dl_cb_notify in nfs4_delegation since a
delegation is either a regular file delegation or a directory
delegation, never both
Refactor alloc_init_deleg() into a common __alloc_init_deleg() base
with a pluggable sc_free callback, and add alloc_init_dir_deleg() which
allocates the page array and notify4 buffer needed for CB_NOTIFY
encoding.
Add skeleton nfsd4_cb_notify_ops with done/release handlers that will
be filled in when the notification path is wired up.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-9-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
fi_deleg_file can be NULLed by put_deleg_file() when fi_delegees drops
to zero during delegation teardown (e.g. DELEGRETURN). Concurrent
accesses from workqueue callbacks -- such as CB_NOTIFY -- can
dereference a NULL pointer if they race with this teardown.
Annotate fi_deleg_file with __rcu and convert all accessors to use
proper RCU primitives:
- rcu_assign_pointer() / RCU_INIT_POINTER() for stores
- rcu_dereference_protected() for reads under fi_lock or where
fi_delegees > 0 guarantees stability
This prepares for a subsequent patch that will use rcu_read_lock +
rcu_dereference + nfsd_file_get to safely acquire a reference from
the CB_NOTIFY callback path without holding fi_lock.
While converting the error-path lease teardown in nfsd_get_dir_deleg(),
also add a nfsd_fsnotify_recalc_mask() call after dropping the lease, to
match the success path and the equivalent teardown in
nfs4_unlock_deleg_lease(). Without it, a failure after the lease is set
leaves the inode's fsnotify mask reflecting a delegation that no longer
exists.
That teardown already unlocks against fi_deleg_file->nf_file rather than
this client's nf->nf_file; document why. The lease's flc_file is set to
fi_deleg_file in nfs4_alloc_init_lease(), which differs from nf when an
earlier client already holds a delegation on the same directory, and
generic_delete_lease() matches on flc_file -- unlocking the wrong file
would leak the lease on the inode.
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-8-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Add a new helper function that will update the mask on the nfsd_file's
fsnotify_mark to be a union of all current directory delegations on an
inode.
Call that when directory delegations are added or removed, since that
can change what fsnotify events nfsd requires from the VFS layer.
The fsnotify_mark is shared by every nfsd_file open on the inode, so
concurrent delegation adds and removes on the same directory can run
nfsd_fsnotify_recalc_mask() in parallel. Because it reads the lease
state and updates the mark in two separate locked sections, a recalc
working from a stale snapshot of the lease list could clobber a
concurrent update and leave the mark missing required events. Add an
nfm_recalc_mutex to the nfsd_file_mark and hold it across the recalc to
serialize callers.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-5-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
When requesting a directory lease, enable the FL_IGN_DIR_* bits that
correspond to the requested notification types.
In nfsd_get_dir_deleg(), gddr_notification[0] will ultimately represent
the notifications that will be provided to the client. For now, that
field is always set to 0. That will change once the upper layers are
ready to start ignoring certain events.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-4-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
RFC8881bis adds some new flags to GET_DIR_DELEGATION that later patches
will consume. In particular, Linux nfsd can't easily provide info about
directory cookies and ordering. The new flags allow it to omit that
information.
There is some risk here -- RFC8881bis is still a working group document,
and has been for years. The changes to directory delegations have been
stable for the last year or so however, so the hope is that those parts
won't change (much).
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-3-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Add the necessary bits to nfs4_1.x and remove the duplicate definitions
from nfs4.h and the uapi nfs4 header. Regenerate the xdr files.
Note that regenerating these files caused conflicts with the definitions
of NFS4_VERIFIER_SIZE and NFS4_FHSIZE in include/uapi/linux/nfs4.h.
These constants are defined by the RFC, and are not part of the kernel
API. They have been removed. Userspace consumers who require those
constants should plan to get them from more authoritative sources.
The nfsstat4 enum defined in the .x is fed to the xdrgen-generated wire
encoder and decoder, which treat every enumerated value as legal on the
wire. Do not carry the NFS4ERR_FIRST_FREE sentinel (which is not a
protocol error code) into the .x; keeping it would make 10097 a value
that could leak onto the wire. Instead base nfsd's internal error codes
(NFSERR_EOF and friends) at an impossible nfsstat4 value, as lockd does
for its nlm__int__* status codes.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616-dir-deleg-v7-2-6cbc7eac0ade@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip,
nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server
sockaddr as the opaque @data argument:
nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
The match callback is later invoked from nlm_traverse_locks() as:
match(lockhost, host);
where the first argument is the nlm_host that owns the lock, and the
second argument is the @data that was originally passed down (here the
server sockaddr). This is the convention every other match callback
relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()):
arg1 is the real nlm_host, arg2 is the caller-supplied reference value.
nlmsvc_match_ip() has had these two arguments reversed ever since the
unlock-by-IP feature was introduced in commit 4373ea84c8 ("lockd:
unlock lockd locks associated with a given server ip"):
return rpc_cmp_addr(nlm_srcaddr(host), datap);
Here @host is actually the server sockaddr, so nlm_srcaddr(host)
dereferences a struct sockaddr as a struct nlm_host and reads garbage
at the offset of h_srcaddr; meanwhile @datap is actually the lock
owner's nlm_host but is compared as a sockaddr. As a result the
comparison practically never matches and locks are not released for the
requested IP.
Swap the arguments so the lock owner's source address is compared
against the requested server address:
return rpc_cmp_addr(nlm_srcaddr(datap), (struct sockaddr *)host);
Fixes: 4373ea84c8 ("lockd: unlock lockd locks associated with a given server ip")
Cc: stable@vger.kernel.org
Signed-off-by: Oscar Ou <oscarou@synology.com>
[ cel: fix the misleading typedef parameter names too ]
Link: https://patch.msgid.link/20260617075738.1151797-1-oscarou@synology.com
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd4_decode_nfstime4() open-codes the nanoseconds upper bound as the
literal (u32)1000000000. Use the named constant NSEC_PER_SEC instead,
matching the NFSv3 setattr check and improving readability.
The original code cast the literal to u32 to force an unsigned
comparison, which matters on 32-bit where tv_nsec is a 32-bit signed
long: an out-of-range u32 wire nseconds (>= 0x80000000) assigned to it
becomes negative and a signed compare against NSEC_PER_SEC (a signed
long) would wrongly pass. Keep that protection by casting tv_nsec to
unsigned long, the same width as tv_nsec, matching timespec64_valid().
No functional change.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616054027.2360930-3-robbieko@synology.com
Signed-off-by: Chuck Lever <cel@kernel.org>
A client can send an NFSv3 SETATTR, CREATE, MKDIR, SYMLINK or MKNOD
carrying an atime or mtime whose nseconds field is out of range. The
value is well-formed on the wire and decodes cleanly into a valid
uint32, but it is not a valid timespec64: tv_nsec must be less than
NSEC_PER_SEC.
Nothing in the setattr path clamps it. notify_change() runs the time
through timestamp_truncate(), which does not reduce tv_nsec below
NSEC_PER_SEC when the filesystem supports nanosecond granularity
(s_time_gran == 1), and the inode atime/mtime setters store it verbatim
(only ctime is normalized, via inode_set_ctime_to_ts()). The
un-normalized value then corrupts on-disk metadata: ext4's
ext4_encode_extra_time() shifts tv_nsec left by EXT4_EPOCH_BITS, which
overflows the 32-bit extra field and clobbers the seconds-epoch bits, so
the stored seconds (and thus the year) are wrong on read-back. XFS with
bigtime mis-stores the timestamp for the same reason.
Validate the client-supplied atime/mtime in the proc handlers and return
NFS3ERR_INVAL before anything is changed. RFC 1813 lists NFS3ERR_INVAL
for SETATTR and describes it as the error for a value the server 'can
not store ... in its own representation'; the client maps it to EINVAL.
Checking in the proc handlers, rather than in nfsd_setattr(), keeps the
rejection in front of object creation. The create operations create the
object before nfsd_create_setattr() runs, so a late failure would leave
the new object behind and turn a non-idempotent request into a namespace
change that reports failure. The check is therefore done up front, for
the create operations before the object is created.
tv_nsec is a long, so the comparison casts it to unsigned long (the same
width) rather than to u32, matching timespec64_valid(). A u32 cast would
truncate on 64-bit; the unsigned long cast also rejects a value that
became negative when an out-of-range u32 wire nseconds was assigned to a
32-bit long.
Only client-supplied times are checked: SET_TO_SERVER_TIME requests
carry no client value. The sattrguard3 ctime is deliberately left alone:
an out-of-range guard simply never matches the object's ctime and yields
NFS3ERR_NOT_SYNC via the existing guardtime comparison, which is the
protocol-correct outcome rather than rejecting the request.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260616054027.2360930-2-robbieko@synology.com
Signed-off-by: Chuck Lever <cel@kernel.org>
The NFSv2 sattr decoder converts the wire useconds to nanoseconds in
svcxdr_decode_sattr():
iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
tmp2 is a u32 and NSEC_PER_USEC is 1000, so the product is computed in
unsigned long. On ILP32 that is 32 bits, and an out-of-range useconds
value such as 4294968 wraps to tv_nsec == 704. The corruption therefore
happens during decode, before any proc function can inspect the value,
and a later range check on tv_nsec would see an in-range result and
accept it. Rejecting in the decoder yields an RPC GARBAGE_ARGS reply.
NFSv2 defines no NFSERR_INVAL, so there is no NFS-level status to return
for a malformed time argument, and the check cannot move to the proc
function the way the v3/v4 nsec range checks do.
Guard the raw useconds before the multiplication and reject values
greater than 1000000. useconds == 1000000 is kept: it is the Sun
convention for "set to the current server time", and the in-tree Linux
NFSv2 client emits it in both the atime and the mtime field for a plain
touch / utimes(file, NULL) (see encode_sattr() and
xdr_encode_current_server_time() in fs/nfs/nfs2xdr.c). Rejecting 1000000
would turn that common operation into a hard decode failure for both
SETATTR and CREATE. 1000000 * NSEC_PER_USEC is 10^9, which does not wrap
on ILP32, so the Sun convention value passes through safely. Only
genuinely out-of-range values (> 1000000) are rejected. The atime and
mtime guards are therefore symmetric.
The decoder only applied the Sun convention in the mtime block, which
clears ATTR_ATIME_SET|ATTR_MTIME_SET when mtime useconds == 1000000. If a
client puts 1000000 in the atime field but not in the mtime field, the
atime block stored an out-of-range tv_nsec (10^9) and left ATTR_ATIME_SET
set, so the bogus value reached the filesystem. Apply the convention in
the atime block as well, clearing ATTR_ATIME_SET so the server uses its
current time and ignores the value. Only ATTR_ATIME_SET is cleared there.
The mtime block keeps its existing behavior, where 1000000 means "set
both atime and mtime to now".
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Robbie Ko <robbieko@synology.com>
[ cel: various tweaks, addenda, and clean-ups ]
Link: https://patch.msgid.link/20260616054027.2360930-1-robbieko@synology.com
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY
attribute with no minimum length. A CAP_NET_ADMIN caller can send a
16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte
OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener,
kernel_bind).
nfsd_nl_listener_set_doit() also parsed and validated each listener
entry inline in two separate loops, interleaved with mutating the
running listener configuration. The validation was duplicated, used an
open-coded "nla_len < sizeof(struct sockaddr)" check that was too short
for AF_INET6, and handled a malformed entry inconsistently depending on
which loop noticed it.
Add an nfsd_nl_validate_listeners() helper that walks the entire list
once and confirms each entry parses, carries both an address and a
transport name, and is long enough for its address family
(sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6)
for AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking
nfsd_mutex or creating the serv, so a malformed request fails cleanly
with no side effects.
Since every entry is known valid by the time the two existing loops
run, drop the redundant presence and per-family length checks from
both, leaving only the nla_parse_nested() call needed to extract the
data.
Fixes: 16a4711774 ("NFSD: add listener-{set,get} netlink command")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260615-nfsd-testing-v5-1-188d75aedda0@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Writing a filesystem path to /proc/fs/nfsd/unlock_filesystem runs
nfsd4_cancel_copy_by_sb() before nfsd_mutex is held and before the
handler confirms that nn->nfsd_serv is set. Once nfsd has shut down,
nfs4_state_destroy_net() has freed nn->conf_id_hashtbl but left the
pointer intact, so the cancel helper iterates freed slab memory as an
array of struct list_head and then dereferences a bogus nfs4_client
when it takes clp->async_lock. A local administrator holding
CAP_SYS_ADMIN can reach this use-after-free by stopping the server and
then writing to unlock_filesystem; KASAN reports a slab-use-after-free
read in nfsd4_cancel_copy_by_sb().
nfsd4_revoke_states() walks the same state tables and for that reason
already runs only under nfsd_mutex with nn->nfsd_serv confirmed
present. Move the async COPY cancel into that protected section so
every NFSv4 state-table walker on this path observes a running server.
Async copies exist only while the server runs, so gating the cancel on
nn->nfsd_serv loses nothing.
Reported-by: Musaab Khan <musaab.khan@protonmail.com>
Fixes: 3daab3112f ("nfsd: cancel async COPY operations when admin revokes filesystem state")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260613-unlock-filesystem-uaf-v1-1-462b9bec8c84@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
In nfs4_preprocess_seqid_op() the stateid is obtained from
nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid
(sc_count) but takes no reference on the stateowner. openlockstateid()
merely casts that stid and likewise takes no reference.
When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is
being torn down, RP_UNHASHED) it has not taken a stateowner reference on
that path. The error handling nevertheless called
nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference
the function never acquired -- risking a stateowner refcount underflow and
use-after-free -- while leaking the sc_count reference held on the stid.
The leaked stid reference can also stall a concurrent
nfsd4_close_open_stateid() waiting for sc_count to drop.
Drop the reference actually held -- the stid -- before retrying. The
stateowner stays alive through the reference held by the stid. This mirrors
the open path in nfsd4_process_open1(), where the put balances a reference
that path explicitly holds on the stateowner.
Fixes: eec7620800 ("nfsd: replace rp_mutex to avoid deadlock in move_to_close_lru()")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-21-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd_dispatch() sets rq_status_counter to an odd value once a request has
been decoded, and back to an even value once it has been fully processed,
forming a seq-lock like protocol with the lockless reader in
nfsd_nl_rpc_status_get_dumpit().
Only the fully successful path restored the counter to even. The cache-hit
(RC_REPLY), drop (RC_DROPIT / RQ_DROPME) and encode-error paths all return
after the odd-valued store without ever bringing the counter back to even.
Once one of those paths is taken, rq_status_counter is left odd: the next
request's decode ORs in 1 (still odd) and only a subsequent successful
encode restores even. While stuck odd, the dumpit reader treats the rqstp
fields as stable and its retry check compares against the same unchanging
odd value, so it never detects concurrent mutation. This exposes actively
mutating fields (e.g. args->ops / args->opcnt during compound decode and
release) to the lockless reader, which can read past the end of the
8-element inline ops array.
Add a helper that advances the counter to the next even value and call it
on every return path that follows the odd-valued store. The decode-error
path is left untouched as it is reached before the counter is set odd.
Fixes: bd9d6a3efa ("NFSD: add rpc_status netlink support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-19-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
shrinker_register() precedes the INIT_LIST_HEAD loop and the
drc_hashsize store. On weakly-ordered architectures (arm64, ppc),
a shrinker scan can observe drc_hashsize before the bucket list
heads are initialized, causing a NULL deref in the DRC shrinker
callback.
Move bucket initialization and the drc_hashsize store before
shrinker_register() so the hash table is fully initialized before
it becomes visible to the shrinker.
Fixes: 8eea99a81c ("nfsd: dynamically allocate the nfsd-reply shrinker")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-18-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd_debugfs_init() runs before nfsd4_init_slabs() in init_nfsd().
If the slab allocation fails, the bare "return retval" bypasses
nfsd_debugfs_exit(), leaving orphan debugfs files with stale fops
pointers into the freed module text.
Move nfsd_debugfs_init() to after the slab init succeeds, so the
early return has no debugfs state to clean up.
Since debugfs is now the more recently initialized of the two, also
update the unwind paths to match reverse-initialization (LIFO) order:
run nfsd_debugfs_exit() before nfsd4_free_slabs() in both the
init_nfsd() error path and exit_nfsd(). The nfsd debugfs files only
reference module-global state and have no dependency on the slab
caches, so that reordering is a cleanup with no functional change.
Fixes: 9fe5ea760e ("NFSD: Add /sys/kernel/debug/nfsd")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-17-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nlmsvc_ops is published by nfsd_lockd_init() and cleared by
nfsd_lockd_shutdown() with plain stores, while lockd dereferences
it unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer
targets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's
.text, so a stale load after rmmod nfsd results in either a NULL
deref or a module-text use-after-free.
Declare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear
via RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module
*owner field to nlmsvc_binding and pin the module across indirect
calls with try_module_get/module_put. When the binding is torn down,
fall back to fput() to avoid leaking struct file references.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-16-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd4_lock() only checks the namespace-wide grace flag when deciding
whether to accept a reclaim LOCK. It does not check the per-client
NFSD4_CLIENT_RECLAIM_COMPLETE bit. An NFSv4.1+ client that has
already sent RECLAIM_COMPLETE can submit lk_reclaim=1 while grace is
still active (e.g. lockd holds the grace list open), and the server
accepts it instead of returning NFS4ERR_NO_GRACE as required by
RFC 8881 section 18.51.3.
The OPEN path already enforces both tiers: the grace check plus the
per-client RECLAIM_COMPLETE check in nfs4_check_open_reclaim(). Add
the equivalent per-client check to the LOCK path.
Fixes: 3b3e7b7223 ("nfsd: reject reclaim request when client has already sent RECLAIM_COMPLETE")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: Correct the RFC citations in the commit message ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-14-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
clients_still_reclaiming() uses separate test_bit() and clear_bit()
calls on NFSD_NET_SOMEBODY_RECLAIMED. A concurrent set_bit() from
the OPEN or LOCK reclaim path arriving between the test and clear
is silently lost, causing the next laundromat tick to end grace
prematurely.
Replace with test_and_clear_bit() to make the read-and-clear atomic.
Fixes: 8c67a210c90c ("nfsd: convert nfsd_net boolean flags to unsigned long flags word")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-13-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
clients_still_reclaiming() computes a deadline from nn->boot_time
(CLOCK_REALTIME, ~1.7 billion) but compares it against
ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).
The comparison is always false — it would take ~54 years of uptime
for BOOTTIME to exceed the REALTIME-derived deadline.
This means any client can hold the server in grace indefinitely by
sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim
operations for all other clients.
Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time
and use it for the deadline computation. boot_time (CLOCK_REALTIME)
is preserved for its cl_boot clientid-nonce role.
Fixes: 20b7d86f29 ("nfsd: use boottime for lease expiry calculation")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-12-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
The BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare()
can inspect the dentry. This causes nfsd_setattr() to skip
fh_want_write(), so notify_change() runs without a mount write
reference.
Add the missing fh_want_write() call after the early fh_verify().
Fixes: cc265089ce ("nfsd: Disable NFSv2 timestamp workaround for NFSv3+")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-11-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
The FL_SLEEP guard uses lk_type & (NFS4_READW_LT | NFS4_WRITEW_LT) which
computes lk_type & 7, non-zero for all valid lock types including
non-blocking ones. This was introduced by commit 7e64c5bc49
("NLM/NFSD: Fix lock notifications for async-capable filesystems") when
refactoring from per-case switch arms.
Replace the bitmask test with explicit equality checks.
Fixes: 7e64c5bc49 ("NLM/NFSD: Fix lock notifications for async-capable filesystems")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-10-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
The loops that compute the supported version range for PROG_MISMATCH
test nfsd_support_acl_version(rqstp->rq_vers) instead of
nfsd_support_acl_version(i), so every iteration fails and the
function returns rpc_prog_unavail instead of rpc_prog_mismatch.
Replace rqstp->rq_vers with the loop variable i, matching the
pattern used by the sibling nfsd_init_request() function.
Fixes: e333f3bbef ("nfsd: Allow containers to set supported nfs versions")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-9-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
The xdrgen-based TIME_DELEG_ACCESS and TIME_DELEG_MODIFY decode arms
store a raw uint32_t nseconds directly into tv_nsec without enforcing
nseconds < NSEC_PER_SEC. The legacy nfsd4_decode_nfstime4 has this
check but the TIME_DELEG paths do not. A malformed timespec can
propagate through notify_change() to disk.
Add range checks in both nfs4xdr.c (SETATTR path) and
nfs4callback.c (CB_GETATTR path).
Fixes: 6ae30d6eb2 ("nfsd: add support for delegated timestamps")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-7-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd4_delegreturn() is the only stateful NFSv4 operation that does
not call nfs4_check_fh() to verify the delegation's file matches
cstate->current_fh. A client can DELEGRETURN with a mismatched
filehandle, destroying the correct delegation but waking the wrong
inode's waiters.
Add the missing nfs4_check_fh() call after the generation check.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-6-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd4_create() stores the return value of nfsd4_acl_to_attr() in
status, but the switch(create->cr_type) block unconditionally
overwrites it in every branch. ACL translation errors are silently
discarded, and the CREATE proceeds without the requested ACL.
Add an early exit check after nfsd4_acl_to_attr(), matching the
pattern already used in nfsd4_setattr().
Fixes: c0cbe70742 ("NFSD: add posix ACLs to struct nfsd_attrs")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: prefer NFS4ERR_BADTYPE over NFS4ERR_ATTRNOTSUPP ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-5-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously
via kfree(), but defers the rqstp struct free via kfree_rcu(). After
svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is
a window where RCU readers that started before list_del_rcu() can still
traverse the thread list and find the rqstp. These readers (e.g.
nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has
already been freed — a use-after-free.
Fix this by moving the kfree of rq_argp and rq_resp into an explicit
call_rcu() callback alongside the struct free. Resources not accessed
by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain
synchronously freed.
Fixes: 812443865c ("sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-4-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd_genl_rpc_status_compose_msg() returns -ENOBUFS on nla_put failure
without calling genlmsg_cancel(), leaving a partial message in the skb.
The caller then propagates -ENOBUFS directly, which the netlink dump
infrastructure treats as a fatal error, aborting the entire dump.
The correct netlink dump convention is:
- Cancel any partial message with genlmsg_cancel()
- If prior messages were added to the skb (skb->len > 0), save the
current iterator position and return skb->len to paginate
- Only return a negative errno when no messages fit at all
Fix compose_msg to cancel the partial message on all nla_put failure
paths, and fix the caller to paginate when possible rather than
returning a fatal error.
A second defect surfaces once pagination actually works: cb->args[1]
records the resume index within the pool named by cb->args[0], but the
inner loop applied it to every pool from cb->args[0] onward. After a
mid-pool pause, a later dump call drains the resume pool and continues
into subsequent pools within the same call, where the stale cb->args[1]
caused the first N threads of each following pool to be skipped. On
per-CPU or per-node pool configurations this silently dropped active
requests from the dump. Apply the saved thread index only to the pool
matching cb->args[0], and start every subsequent pool from thread 0.
Fixes: bd9d6a3efa ("NFSD: add rpc_status netlink support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: fold in 20/21 to avoid bisect hazard ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-3-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
The hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit()
is missing a read memory barrier (smp_rmb) before its second counter
check. The standard kernel read_seqcount_retry() includes smp_rmb()
to ensure that all data reads complete before the counter is re-checked.
Without this barrier, on weakly-ordered architectures (ARM, POWER),
the CPU may reorder field reads past the second counter check, making
the retry logic ineffective: it could observe a consistent counter pair
while reading fields that have been concurrently modified by the writer.
Add smp_rmb() before the second counter check to order the field reads
ahead of it, matching the barrier semantics of the standard seqcount
read-side. The begin-side smp_load_acquire() already pairs with the
smp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering
the field reads, the retry check no longer needs acquire semantics and
reads the counter with a plain READ_ONCE(), as read_seqcount_retry()
does.
Fixes: bd9d6a3efa ("NFSD: add rpc_status netlink support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: Use READ_ONCE instead of smp_load_acquire() ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-2-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd4_release_compoundargs() resets args->ops to the inline iops[8]
array when the dynamically-allocated ops buffer is freed, but leaves
args->opcnt at its original value (which can be up to 200 for NFSv4.1+
compounds).
If rq_status_counter is stuck at an odd value (which can happen when
nfsd_dispatch() hits an error path after setting it odd), the RPC
status dumpit handler reads min(opcnt, 16) entries from args->ops[].
Since iops only has 8 elements and is the last field in struct
nfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory
and leaks it to userspace via netlink.
Zero opcnt unconditionally in nfsd4_release_compoundargs() so stale
compound metadata is never exposed through the status interface.
Fixes: bd9d6a3efa ("NFSD: add rpc_status netlink support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ]
Link: https://patch.msgid.link/20260611-nfsd-testing-v2-1-5b90e276f2d9@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
When a SETATTR request includes FATTR4_WORD2_TIME_DELEG_ACCESS or
FATTR4_WORD2_TIME_DELEG_MODIFY in the attribute bitmap, nfsd4_setattr()
sets deleg_attrs=true and calls nfs4_preprocess_stateid_op() to validate
the stateid.
If the client supplies the NFSv4 "one stateid" (all-0xFF bytes),
check_special_stateids() returns nfs_ok without populating the output
nfs4_stid pointer, because the special-stateid path in
nfs4_preprocess_stateid_op() jumps to done: with s==NULL, and the
"if (s)" block that would set *cstid is skipped. The local variable `st`
remains NULL.
Back in nfsd4_setattr(), the if (deleg_attrs) block then unconditionally
dereferences st->sc_type (at offset 4 from NULL), causing a kernel oops.
This is remotely triggerable by any NFSv4 client: send COMPOUND [PUTROOTFH,
SETATTR(ONE_STATEID, {bmval2=FATTR4_WORD2_TIME_DELEG_ACCESS, ...})].
No authentication, delegation, or prior state is required.
Fix by adding a NULL check before the dereference. A special stateid is
not a delegation stateid, so the existing nfserr_bad_stateid return value
is already correct; we only need to guard the pointer dereference itself.
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Nikol Kuklev <nikolk202@gmail.com>
Signed-off-by: Chuck Lever <cel@kernel.org>
The header for commit e75b23f9e3 ("nfsd: check d_can_lookup in
fh_verify of directories") details the assumption that justified
adding the WARN_ON_ONCE to nfsd_mode_check(), that assumption is
invalid (in the case of NFS reexport).
When NFSD exports an NFS filesystem it is very possible for
nfsd_mode_check() to encounter a @dentry that doesn't have
i_op->lookup (see nfs_fhget()'s NFS_ATTR_FATTR_MOUNTPOINT and
NFS_ATTR_FATTR_V4_REFERRAL handling, and d_flags_for_inode()).
So remove nfsd_mode_check()'s WARN_ON_ONCE(). The nfserr_notdir
return on that branch must stay. It guards the subsequent
lookup_one_unlocked() -> __lookup_slow() path, which calls
inode->i_op->lookup() with no NULL check, so returning nfserr_notdir
is what keeps a client LOOKUP into such a @dentry from dereferencing
a NULL method pointer.
Fixes: e75b23f9e3 ("nfsd: check d_can_lookup in fh_verify of directories")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Link: https://patch.msgid.link/20260612191410.50177-1-snitzer@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
When a client uses its highest session slot, nfsd4_sequence() grows
the session's slot table by 20%, up to NFSD_MAX_SLOTS_PER_SESSION, on
the theory that a client at its ceiling can put more requests in
flight. The heuristic keys only on the client's appetite, so its
incentive runs backwards: the client that keeps every slot busy --
already the largest consumer of the thread pool -- is the one the
server rewards with still more slots. A single session's table can
climb toward 2048 slots even on a server with far fewer threads to
run them.
A slot stays occupied for a full round trip -- request out, server
processing, reply back -- but ties up an nfsd thread only during the
processing. When the round trip is short, one slot per thread keeps the
pool busy and further slots add only backlog. Across a high-RTT link
more slots are in flight than the pool serves at any instant, so there
extra slots do raise throughput by masking link latency -- but that
is the client's call to make by sizing its session at CREATE_SESSION,
not a reason for the server to grow every busy session toward 2048. Cap
on-demand growth at the thread ceiling, the point past which added
slots stop buying concurrency on a short round trip, so a table stops
climbing once it can keep every thread busy.
Apply the cap per session rather than across the namespace. A session
cannot use another session's slots, so one client's table size has no
bearing on what a second client may grow to. A shared per-namespace
budget would also misbehave at the floor: every active session holds
one slot that cannot be reclaimed, so once the session count reaches
the thread ceiling those floors alone exhaust the budget, pinning the
one busy client small while most of the pool sits idle. NFSD sizes
its pool dynamically, so compare against svc_serv_maxthreads(), the
configured maximum, rather than the running thread count, which
tracks recent load and would deny a client resuming from idle the
slots it needs to ramp up.
This removes a perverse incentive without becoming slot admission
control. A client still sizes its sessions directly at CREATE_SESSION,
bounded by NFSD_MAX_SLOTS_PER_SESSION, and a client determined to
monopolize threads can do so through that path regardless of this
change. Enforcing per-client fairness against thread starvation
belongs in the dispatch layer, not in slot accounting.
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@hammerspace.com>
Link: https://patch.msgid.link/20260610-nfsd-slot-growth-clamp-v1-5-7b966700df0b@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
nfsd_total_target_slots sums "target_slots - 1" across sessions
rather than the full target. Its sole consumer, the NFSv4.1 session
slot shrinker's count callback, must report only reclaimable slots,
and slot 0 is never reclaimable while a session is active. That
correction is open-coded where a session's full target enters and
leaves the counter, as "i - 1" on alloc and "from ?: 1" on free,
and reads as an unexplained fudge.
Give nfsd_total_target_slots the full-target meaning its name
implies, and move the reclaimability correction to the single place
that consumes it: nfsd_slot_count() subtracts nfsd_total_sessions, a
new tally of the sessions on nfsd_session_list. One correction at the
consumer is clearer than repeating it wherever a session's target
enters or leaves the counter.
The reclaimable figure the shrinker sees is unchanged: slot 0 was
never reclaimable and still is not. The change only relocates the
minus-slot-0 correction.
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@hammerspace.com>
Link: https://patch.msgid.link/20260610-nfsd-slot-growth-clamp-v1-2-7b966700df0b@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
A pooled RPC service sizes its threads dynamically, growing and
shrinking each pool between its minimum and maximum bounds as load
varies. The count of running threads therefore reflects recent
demand, not the service's capacity. A consumer that sizes a data
structure against the concurrency the service can sustain -- NFSD's
NFSv4 session slot tables, for one -- needs that stable ceiling, and
computing it means summing sp_nrthrmax across every pool.
Add svc_serv_maxthreads() so the summation, and its dependence
on the layout of struct svc_serv and struct svc_pool, stays within
sunrpc. The read is lock-free: pool maxima change only when a service
is reconfigured, a path callers already serialize against startup and
shutdown, so a racing reader observes at worst a transient value. This
is acceptable for the sizing heuristics that will consume it.
nfsd_nrthreads() already sums sp_nrthrmax across pools by hand; convert
it to svc_serv_maxthreads(), giving the new export an in-tree consumer
and removing a copy of the dependence on svc_serv internals.
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@hammerspace.com>
Link: https://patch.msgid.link/20260610-nfsd-slot-growth-clamp-v1-1-7b966700df0b@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>
Simplifies the code and removes a 'not obviously bounded' strcpy().
Delete the local function nlmdbg_cookie2a() that did the equivalent.
There is no need to worry about cookie->len being more than
NLM_MAXCOOKIELEN (32), the buffer holding it is only that long.
The existing length checks must pre-date this code being added in 2.4.26.
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Link: https://patch.msgid.link/20260608212042.25476-1-david.laight.linux@gmail.com
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The shrinker, GC worker, and fsnotify/lease callbacks can unhash an
nfsd_file from the rhashtable and then call
nfsd_file_dispose_list_delayed() to move it to the per-net dispose list.
If nfsd_file_cache_shutdown_net() runs concurrently, its rhashtable walk
misses the already-unhashed file, and its drain of the per-net dispose
list can run before the file has been queued. The file then sits on
the per-net list with no thread to drain it, leaking both the file and
its associated state.
The GC worker and shrinker already hold nfsd_gc_lock while walking the
LRU, but in the original code they release it before calling
nfsd_file_dispose_list_delayed(). The fsnotify/lease path
(nfsd_file_close_inode) has no synchronization at all.
Fix this by:
1. Widening nfsd_gc_lock in both nfsd_file_gc() and nfsd_file_lru_scan()
to cover the nfsd_file_dispose_list_delayed() call.
2. Wrapping nfsd_file_close_inode() in nfsd_gc_lock so that all three
callers of nfsd_file_dispose_list_delayed() hold the lock.
3. Adding a spin_lock/unlock(nfsd_gc_lock) barrier in
nfsd_file_cache_shutdown_net() after the purge, so that any
in-progress disposal has fully completed before the per-net list
is drained.
All operations inside the lock are non-sleeping (rhashtable lookups,
atomic bit/refcount ops, list moves, svc_wake_up), so the spinlock is
appropriate.
Fixes: ffb4025961 ("nfsd: Don't leave work of closing files to a work queue")
Cc: stable@vger.kernel.org # v6.15+
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Assisted-by: Claude:claude-opus-4-8
Link: https://patch.msgid.link/20260604-nfsd-testing-v4-1-3aeb1479c5bb@kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_file_dispose_list_delayed() defers fput() to nfsd service threads
via a per-net freeme queue, preventing the shrinker and GC worker from
bearing the cost of closing files (see ffb4025961). However, the
queue lives in a separately-allocated struct nfsd_fcache_disposal that
is freed by nfsd_free_fcache_disposal_net() during per-net teardown.
The global shrinker, laundrette, and fsnotify callbacks can still be
inside nfsd_file_dispose_list_delayed() dereferencing that pointer,
causing a use-after-free.
Inline the spinlock and freeme list directly into struct nfsd_net (as
fcache_dispose_lock and fcache_dispose_list), eliminating the separately
allocated struct nfsd_fcache_disposal entirely. These fields now have
the same lifetime as the net namespace itself, so there is no dangling
pointer to chase.
nfsd_file_cache_start_net() now just initializes the inline fields and
cannot fail due to allocation. nfsd_file_cache_shutdown_net() drains
the inline list directly instead of freeing a separate struct. The
alloc/free helpers are removed.
Fixes: 1463b38e7c ("NFSD: simplify per-net file cache management")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260602-nfsd-testing-v2-7-e4ea62e3cd5c@kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
