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2026-08-10nfsd: allow nfsd to get a dir lease with an ignore maskJeff Layton
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>
2026-08-10nfs_common: add new NOTIFY4_* flags proposed in RFC8881bisJeff Layton
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>
2026-08-10nfsd: add protocol support for CB_NOTIFYJeff Layton
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>
2026-08-10nfsd: check fl_lmops in nfsd_breaker_owns_lease()Jeff Layton
Any lease created by nfsd will have its fl_lmops set to nfsd_lease_mng_ops. Do a quick check for that first when testing whether the lease breaker owns the lease. Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Link: https://patch.msgid.link/20260616-dir-deleg-v7-1-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever <cel@kernel.org>
2026-08-10lockd: fix swapped arguments in nlmsvc_match_ip()Oscar Ou
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 4373ea84c84d ("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: 4373ea84c84d ("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>
2026-08-10nfsd: use NSEC_PER_SEC in nfsd4_decode_nfstime4()Robbie Ko
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>
2026-08-10nfsd: reject out-of-range nseconds in NFSv3 SETATTR and create opsRobbie Ko
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: 1da177e4c3f4 ("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>
2026-08-10nfsd: reject out-of-range useconds in NFSv2 SETATTR/CREATERobbie Ko
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: 1da177e4c3f4 ("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>
2026-08-10nfsd: validate sockaddr length per family in listener_setJeff Layton
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: 16a471177496 ("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>
2026-08-10NFSD: Annotate caller preconditions for the state-table walkersChuck Lever
The state-table walkers now assert nfsd_mutex with lockdep_assert_held() and document the nfsd_mutex / nn->nfsd_serv precondition in a Context: kdoc section, so the next caller added to this path cannot silently reintroduce the same use-after-free. Reviewed-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260613-unlock-filesystem-uaf-v1-3-462b9bec8c84@kernel.org Signed-off-by: Chuck Lever <cel@kernel.org>
2026-08-10NFSD: Prevent post-shutdown use-after-free in unlock_filesystemChuck Lever
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: 3daab3112f03 ("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>
2026-08-10nfsd: drop the stateid, not the stateowner, on seqid_op replay retryJeff Layton
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: eec762080008 ("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>
2026-08-10nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit pathsJeff Layton
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: bd9d6a3efa97 ("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>
2026-08-10nfsd: initialize DRC hash table before registering shrinkerJeff Layton
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: 8eea99a81c6f ("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>
2026-08-10nfsd: move nfsd_debugfs_init() after nfsd4_init_slabs() in init_nfsd()Jeff Layton
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: 9fe5ea760e64 ("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>
2026-08-10lockd, nfsd: RCU-protect nlmsvc_ops dispatchJeff Layton
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: 1da177e4c3f4 ("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>
2026-08-10nfsd: reject reclaim LOCK after RECLAIM_COMPLETEJeff Layton
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: 3b3e7b72239a ("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>
2026-08-10nfsd: use test_and_clear_bit for somebody_reclaimed to prevent lost updateJeff Layton
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>
2026-08-10nfsd: fix clock domain mismatch in clients_still_reclaiming()Jeff Layton
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: 20b7d86f29d3 ("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>
2026-08-10nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()Jeff Layton
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: cc265089ce1b ("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>
2026-08-10nfsd: fix FL_SLEEP being set unconditionally for all LOCK typesJeff Layton
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 7e64c5bc497c ("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: 7e64c5bc497c ("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>
2026-08-10nfsd: fix version mismatch loops in nfsd_acl_init_request()Jeff Layton
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: e333f3bbefe3 ("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>
2026-08-10nfsd: validate nseconds in TIME_DELEG decode pathsJeff Layton
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: 6ae30d6eb26b ("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>
2026-08-10nfsd: add filehandle match check to nfsd4_delegreturn()Jeff Layton
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: 1da177e4c3f4 ("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>
2026-08-10nfsd: check nfsd4_acl_to_attr() return value in nfsd4_create()Jeff Layton
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: c0cbe70742f4 ("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>
2026-08-10sunrpc: defer rq_argp and rq_resp free until after RCU grace periodJeff Layton
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: 812443865c5f ("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>
2026-08-10nfsd: fix netlink dumpit error handling for rpc_status_getJeff Layton
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: bd9d6a3efa97 ("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>
2026-08-10nfsd: add missing read barrier to rpc_status_get dumpit seqcount retryJeff Layton
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: bd9d6a3efa97 ("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>
2026-08-10nfsd: clear opcnt on compound arg release to prevent OOB readJeff Layton
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: bd9d6a3efa97 ("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>
2026-08-10nfsd: fix null dereference in nfsd4_setattr for deleg timestamp attrsNikol Kuklev
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: 7e13f4f8d27d ("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>
2026-08-10NFSD: remove flawed WARN_ON_ONCE from nfsd_mode_checkMike Snitzer
The header for commit e75b23f9e323 ("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: e75b23f9e323 ("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>
2026-08-10NFSD: Bound on-demand DRC slot growth by the thread ceilingChuck Lever
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>
2026-08-10NFSD: Document and rename the NFSv4.1 session slot shrinker callbacksChuck Lever
Clean up: To prevent their reuse by generic code, rename the NFSv4.1 session slot shrinker's callback functions to make it clear they are for use only by the shrinker. Though they are static, callbacks are invoked from outside nfsd.ko, so they need appropriate kdoc comments that document their API contracts. 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-v1-4-7b966700df0b@kernel.org Signed-off-by: Chuck Lever <cel@kernel.org>
2026-08-10NFSD: Clean up documenting comment for reduce_session_slots()Chuck Lever
Fix typos. The usual convention is to not use kdoc-style for internal (static) functions. 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-v1-3-7b966700df0b@kernel.org Signed-off-by: Chuck Lever <cel@kernel.org>
2026-08-10NFSD: Count slot 0 in nfsd_total_target_slotsChuck Lever
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>
2026-08-10SUNRPC: Add svc_serv_maxthreads() to report the thread ceilingChuck Lever
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>
2026-08-10lockd: Use "%*phN" to dprintk() a cookieDavid Laight
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>
2026-08-10NFSD: fix up error returned by write_threads()Scott Mayhew
Previously, writing 0 to /proc/fs/nfsd/threads would return 0 if the NFS server wasn't running. After commit 14282cc3cfa2 ("NFSD: don't start nfsd if sv_permsocks is empty"), -EIO is returned. Existing scripts don't expect this behavior. Add a check to bypass the call to nfsd_svc() when newthreads is 0 and the NFS server is already stopped. Fixes: 14282cc3cfa2 ("NFSD: don't start nfsd if sv_permsocks is empty") Cc: stable@vger.kernel.org Signed-off-by: Scott Mayhew <smayhew@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260608131402.95625-1-smayhew@redhat.com Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10net/sunrpc/svcauth_unix: Use strscpy() to copy strings into arraysDavid Laight
Replacing strcpy() with strscpy() ensures that overflow of the target buffer cannot happen. Signed-off-by: David Laight <david.laight.linux@gmail.com> Link: https://patch.msgid.link/20260608095523.2606-16-david.laight.linux@gmail.com Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: close shrinker/GC/fsnotify vs per-net shutdown race in filecacheJeff Layton
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: ffb402596147 ("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>
2026-08-10nfsd: unify cleanups in nfsd_cross_mnt() exitsAl Viro
Instead of having a separate path_put() on each failure exit, as well as on the normal path, let's move all of those past the point where these codepaths join. We want to keep the ordering between path_put() and exp_put(), so move that one as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260602-nfsd-testing-v2-9-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: fix fcache_disposal UAF by inlining dispose state into nfsd_netJeff Layton
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 ffb402596147). 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: 1463b38e7cf3 ("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>
2026-08-10nfsd: fix refcount leak in nfsd_file_lru_add on insertion failureJeff Layton
nfsd_file_lru_add() unconditionally increments nf_ref before attempting to insert the nfsd_file into the LRU via list_lru_add_obj(). If the insertion fails (the item is already linked), the incremented reference is never released, permanently inflating the refcount. The LRU shrinker callback (nfsd_file_lru_cb) uses refcount_dec_if_one() to reclaim entries, which requires nf_ref == 1. An inflated refcount therefore blocks eviction of the affected file cache entry for the lifetime of the nfsd instance. While this failure path is currently unreachable -- the sole caller in nfsd_file_do_acquire() operates on freshly-allocated objects that cannot already be on the LRU -- it represents a latent bug that would become exploitable if a future change adds another call site or alters the PENDING protocol. Fix this by: - Adding a compensating refcount_dec() on the failure path. Bare refcount_dec (rather than nfsd_file_put) is correct here because the caller in nfsd_file_do_acquire still holds its own construction reference, so the count goes from 2 back to 1 without risk of reaching zero. - Changing WARN_ON(1) to WARN_ON_ONCE(1) to prevent log flooding if this path is ever hit repeatedly. - Returning early on failure to skip the unnecessary call to nfsd_file_schedule_laundrette(), since no entry was added to the LRU. Fixes: 56221b42d717 ("nfsd: filecache: don't repeatedly add/remove files on the lru list") 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-v2-6-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storageJeff Layton
struct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain "struct sockaddr" (16 bytes). When an IPv6 NFS client is connected, nfsd_genl_rpc_status_compose_msg() casts these fields to "struct sockaddr_in6 *" (28 bytes) and reads sin6_addr at offset 8..24, which extends 8 bytes past the end of the 16-byte sockaddr field into the adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8 bytes of truncated IPv6 address followed by 8 bytes of rq_flags to userspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes. This is reachable by any unprivileged process in the network namespace because NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without GENL_ADMIN_PERM. Fix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the IPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage) bytes in the memcpy calls so the full address is captured, and zero-initializing the genl_rqstp stack variable to prevent leaking uninitialized tail bytes through netlink. Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support") 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-v2-5-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: guard nfsd_serv deref in nfsd_file_net_disposeChris Mason
nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd service thread loop calls it to drain entries that the filecache garbage collector and shrinker append via nfsd_file_dispose_list_delayed(). During per-net teardown, nn->nfsd_serv is cleared before the filecache laundrette is shut down, so the service thread can still run a dispose pass that finds more than eight entries on l->freeme and dereferences a NULL svc_serv: nfsd service thread loop nfsd_file_net_dispose(nn) if (!list_empty(&l->freeme)) { ... svc_wake_up(nn->nfsd_serv); /* nn->nfsd_serv == NULL */ } The sibling helper nfsd_file_dispose_list_delayed() already documents this ordering and caches nn->nfsd_serv into a local before testing it for NULL. nfsd_file_net_dispose() was introduced with the same raw svc_wake_up(nn->nfsd_serv) call and never picked up the guard. Fix by loading nn->nfsd_serv into a local svc_serv pointer and only calling svc_wake_up() when it is non-NULL, matching the pattern in nfsd_file_dispose_list_delayed(). Fixes: ffb402596147 ("nfsd: Don't leave work of closing files to a work queue") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Chris Mason <clm@meta.com> Link: https://patch.msgid.link/20260602-nfsd-testing-v2-4-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10NFS/localio: fix ref leak on nfs_uuid_add_file failureChris Mason
When nfs_uuid_add_file() races with nfs_uuid_put() tearing down uuid->net, it returns -ENXIO without publishing nfl->nfs_uuid via rcu_assign_pointer(). nfs_open_local_fh() then enters its error branch and only releases the slot's file ref and its paired net ref plus its own entry-time net ref, while the close path is a no-op: nfs_close_local_fh() nfs_uuid = rcu_dereference(nfl->nfs_uuid); if (!nfs_uuid) { rcu_read_unlock(); return; } /* always */ nfsd_open_local_fh() returns localio holding a caller-owned +1 nfsd_file reference (from nfsd_file_get() after nfsd_file_acquire_local()) and an entry-time nfsd_net reference (from its first nfsd_net_try_get()) embedded as nf->nf_net. Both are leaked on the failure path, pinning one nfsd_file (and the underlying struct file, dentry, inode) and one nfsd_net_ref per occurrence, which blocks nfsd_net and netns teardown. Fix by releasing the caller-owned file ref and its net ref through the existing helper, using a stack-local RCU pointer so the helper can xchg it out, then returning -ENXIO so callers do not dereference a localio whose slot has been cleared: struct nfsd_file __rcu *tmp = RCU_INITIALIZER(localio); nfs_to_nfsd_file_put_local(pnf); nfs_to_nfsd_file_put_local(&tmp); localio = ERR_PTR(-ENXIO); The trailing nfs_to_nfsd_net_put(net) continues to release the outer net ref, so all three nfsd_net_try_get() increments are balanced on the error branch. Fixes: fdd015de7679 ("NFS/localio: nfs_uuid_put() fix races with nfs_open/close_local_fh()") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Chris Mason <clm@meta.com> Link: https://patch.msgid.link/20260602-nfsd-testing-v2-3-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: hold rcu across localio cmpxchg retryChris Mason
nfsd_file objects are freed via call_rcu (filecache.c:296), and nfsd_file_slab is created without SLAB_TYPESAFE_BY_RCU (KMEM_CACHE(nfsd_file, 0) at filecache.c:789), so the slab page backing a freed nfsd_file becomes freely reclaimable once the RCU grace period elapses. The again: retry block in nfsd_open_local_fh() loads a pointer with cmpxchg and then calls nfsd_file_get(new) (which is refcount_inc_not_zero) without holding rcu_read_lock. The sole caller nfs_open_local_fh() drops rcu_read_lock before invoking this helper, so no outer reader-side critical section covers the load. CPU 0 (nfsd_open_local_fh) CPU 1 (nfsd_file_put_local) ----- ----- new = cmpxchg(pnf, NULL, ...) nf = xchg(pnf, NULL) nfsd_file_put(nf) last ref -> call_rcu() /* grace period elapses; slab page recycled */ nfsd_file_get(new) refcount_inc_not_zero(&new->nf_ref) /* operates on recycled memory */ A non-zero word at the nf_ref offset of the recycled object makes the refcount bump appear to succeed, and the caller then dereferences new->nf_net and new->nf_file out of freed memory. Fix by taking rcu_read_lock() immediately before the cmpxchg and releasing it on all three exits of the if (new) block: the goto-again retry, the lost-race cleanup path, and the install-succeeded path. nfsd_file_put() and nfsd_net_put() stay outside the RCU section so they remain free to block. Fixes: e6f7e1487ab5 ("nfs_localio: simplify interface to nfsd for getting nfsd_file") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Chris Mason <clm@meta.com> Link: https://patch.msgid.link/20260602-nfsd-testing-v2-2-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: defer vfree of compound ops to fix rpc_status UAFJeff Layton
The rpc_status netlink dumpit walks every in-flight svc_rqst under rcu_read_lock and, for NFSv4 requests, reads opnums out of args->ops[]. But args->ops is a separate vmalloc buffer freed synchronously by vfree() in nfsd4_release_compoundargs() at the end of every compound. The dumpit's rcu_read_lock pins the svc_rqst struct itself (freed via kfree_rcu), but nothing defers the vfree of the ops buffer across the RCU grace period. A concurrent compound completion can therefore free the buffer while the dumpit is reading it — a use-after-free on vmalloc memory. The trailing seqcount recheck (smp_load_acquire of rq_status_counter) cannot undo a load that already retired against freed memory. Fix by replacing vfree(args->ops) with kvfree_rcu_mightsleep(), which defers the free until after an RCU grace period. This makes the existing rcu_read_lock in the dumpit sufficient to protect the read. The tradeoff is that completed compound ops buffers (up to 200 * sizeof(struct nfsd4_op)) persist in memory slightly longer, across one grace period, before being reclaimed. Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support") 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-v2-1-e4ea62e3cd5c@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10rpcrdma: arm rn_done before publishing the notificationChuck Lever
rpcrdma_rn_register() inserts @rn into rd_xa with xa_alloc() before storing the caller's callback in rn->rn_done. The xarray makes @rn reachable to rpcrdma_remove_one(), which walks rd_xa and invokes rn->rn_done(rn) for every registered notification. A device removal that races a fresh registration can therefore observe @rn with rn_done still NULL, because the notification objects are zero allocated by their owners, and call through a NULL function pointer. Store rn->rn_done before xa_alloc() publishes @rn. The xarray's store-side and load-side ordering then guarantees that any CPU which finds @rn in rd_xa also observes the armed callback. rpcrdma_rn_unregister() treats a non-NULL rn_done as the sentinel for a completed registration, so the early store must not survive a failed registration. Clear rn_done again when xa_alloc() fails. Were it left set, the failed-accept cleanup path would call rpcrdma_rn_unregister() on an @rn that was never inserted, erasing an unrelated rd_xa slot and underflowing rd_kref. Fixes: 7e86845a0346 ("rpcrdma: Implement generic device removal") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260601201703.46078-1-cel@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-08-10nfsd: release OPEN-decoded posix ACLs via op_releaseJeff Layton
nfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates refcounted struct posix_acl objects via posix_acl_alloc() and stores them in open->op_pacl and open->op_dpacl. These pointers must be released once the OPEN compound finishes. When nfsd4_decode_open_claim4() returns a non-seqid-mutating error, the dispatcher short-circuits before op_func runs: nfsd4_proc_compound() if (op->status && op->opnum == OP_OPEN) op->status = nfsd4_open_omfg(...) if (!seqid_mutating_err(ntohl(op->status))) return op->status; /* nfsd4_open() never runs */ ... opdesc->op_release(&op->u) /* must still release op_pacl/op_dpacl */ Before this change OP_OPEN had no .op_release in nfsd4_ops[], and the release pair lived inside nfsd4_open() at its out_err: label. On the short-circuit path nfsd4_open() is never invoked, so both posix_acl refs leak on every malformed OPEN compound that carries valid POSIX ACL createhow4 attributes. Add nfsd4_open_release() and wire it as .op_release for OP_OPEN. posix_acl_release() is NULL-safe, so the single release site covers both the normal path and the nfsd4_open_omfg short-circuit. Remove the matching posix_acl_release() pair from nfsd4_open()'s out_err: label to avoid double-releasing. The compound loop has two encoding branches: nfsd4_encode_operation() for normal ops, and nfsd4_encode_replay() for v4.0 replayed ops. op_release was only called from nfsd4_encode_operation(), so resources attached to op->u leak on the replay path. Move the op_release() call out of nfsd4_encode_operation() and the replay branch, placing it after the if-else in nfsd4_proc_compound(). This gives a single call site in a fairly obviously-correct place, covering both the normal encoding and replay paths. Fixes: 5fc51dfc2eb1 ("NFSD: Add support for XDR decoding POSIX draft ACLs") Cc: stable@vger.kernel.org Signed-off-by: Chris Mason <clm@meta.com> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260601-nfsd-testing-v3-1-a31cd10bdd4f@kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>