linux-stable.git/fs/lockd, branch linux-rolling-lts

lockd: Plug nlm_file refcount leak on cached nlm_do_fopen() failure

2026-07-24T14:16:59+00:00

commit 70a38f87bed7f0694fd07988b47b2db1e10d8df3 upstream.

The cached-file path in nlm_lookup_file() reaches the found: label
unconditionally, even when nlm_do_fopen() fails. At that label
*result and file->f_count are updated before the error is returned.
The wrappers nlm3svc_lookup_file() and nlm4svc_lookup_file() then
bail out of their switch without copying *result back to their
caller, so the proc handler's local nlm_file pointer remains NULL
and the cleanup path skips nlm_release_file(). The f_count
increment is never released, and nlm_traverse_files() can no
longer reap the file because its refcount never returns to zero
between requests.

Short-circuit the cached path so neither *result nor f_count is
touched when nlm_do_fopen() fails on a hashed nlm_file.

Fixes: 7f024fcd5c97 ("Keep read and write fds with each nlm_file")
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

lockd: Plug nlm_file leak when nlm_do_fopen() fails

2026-07-24T14:16:59+00:00

commit f16a1513452edb532fec81e591c64c320866719c upstream.

A client can repeatedly drive nlm_do_fopen() failures by presenting
file handles that the underlying export rejects. After kzalloc_obj()
succeeds in nlm_lookup_file(), the freshly allocated nlm_file is not
yet inserted into nlm_files[]. The nlm_do_fopen() failure path jumps
to out_unlock, which releases nlm_file_mutex and returns without
freeing the allocation, so each failure leaks one nlm_file.

Route the failure through out_free so kfree() runs before the
function returns.

Fixes: 7f024fcd5c97 ("Keep read and write fds with each nlm_file")
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

lockd: fix TEST handling when not all permissions are available.

2026-07-04T11:44:14+00:00

[ Upstream commit 0b474240327cebeff08ad429e8ed3cfc6c8ee816 ]

The F_GETLK fcntl can work with either read access or write access or
both.  It can query F_RDLCK and F_WRLCK locks in either case.

However lockd currently treats F_GETLK similar to F_SETLK in that read
access is required to query an F_RDLCK lock and write access is required
to query a F_WRLCK lock.

This is wrong and can cause problems - e.g.  when qemu accesses a
read-only (e.g. iso) filesystem image over NFS (though why it queries
if it can get a write lock - I don't know.  But it does, and this works
with local filesystems).

So we need TEST requests to be handled differently.  To do this:

- change nlm_do_fopen() to accept O_RDWR as a mode and in that case
  succeed if either a O_RDONLY or O_WRONLY file can be opened.
- change nlm_lookup_file() to accept a mode argument from caller,
  instead of deducing base on lock time, and pass that on to nlm_do_fopen()
- change nlm4svc_retrieve_args() and nlmsvc_retrieve_args() to detect
  TEST requests and pass O_RDWR as a mode to nlm_lookup_file, passing
  the same mode as before for other requests.  Also set
   lock->fl.c.flc_file to whichever file is available for TEST requests.
- change nlmsvc_testlock() to also not calculate the mode, but to use
  whatever was stored in lock->fl.c.flc_file.

This behaviour of lockd - requesting O_WRONLY access to TEST for
exclusive locks - has been present at least since git history began.
However it was hidden until recently because knfsd ignored the access
requested by lockd and required only READ access for all locking
requests (unless the underlying filesystem provided an f_op->open
function which checked access permissions).

The commit mentioned in Fixes: below changed nfsd_permission() to NOT
override the access request for LOCK requests and this exposed the bug
that we are now fixing.

Note that there is another issue that this patch does not address.
The flock(.., LOCK_EX) call is permitted on a read-only file descriptor.
Linux NFS maps this to NLM locking as whole-file byte-range locks.
nfsd will see this as though it were fcntl( F_SETLK (F_WRLCK)) and will
now require write access, which it might not be able to get.
It is not clear if this is a problem in practice, or what the best
solution might be.  So no attempt is made to address it.

Reported-by: Tj 
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1128861
Fixes: 4cc9b9f2bf4d ("nfsd: refine and rename NFSD_MAY_LOCK")
Reviewed-by: Jeff Layton 
Signed-off-by: NeilBrown 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

lockd: fix vfs_test_lock() calls

2026-01-08T09:17:10+00:00

commit a49a2a1baa0c553c3548a1c414b6a3c005a8deba upstream.

Usage of vfs_test_lock() is somewhat confused.  Documentation suggests
it is given a "lock" but this is not the case.  It is given a struct
file_lock which contains some details of the sort of lock it should be
looking for.

In particular passing a "file_lock" containing fl_lmops or fl_ops is
meaningless and possibly confusing.

This is particularly problematic in lockd.  nlmsvc_testlock() receives
an initialised "file_lock" from xdr-decode, including manager ops and an
owner.  It then mistakenly passes this to vfs_test_lock() which might
replace the owner and the ops.  This can lead to confusion when freeing
the lock.

The primary role of the 'struct file_lock' passed to vfs_test_lock() is
to report a conflicting lock that was found, so it makes more sense for
nlmsvc_testlock() to pass "conflock", which it uses for returning the
conflicting lock.

With this change, freeing of the lock is not confused and code in
__nlm4svc_proc_test() and __nlmsvc_proc_test() can be simplified.

Documentation for vfs_test_lock() is improved to reflect its real
purpose, and a WARN_ON_ONCE() is added to avoid a similar problem in the
future.

Reported-by: Olga Kornievskaia 
Closes: https://lore.kernel.org/all/20251021130506.45065-1-okorniev@redhat.com
Signed-off-by: NeilBrown 
Fixes: 20fa19027286 ("nfs: add export operations")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Move the svc_rpcb_cleanup() call sites

2025-09-21T23:24:50+00:00

Clean up: because svc_rpcb_cleanup() and svc_xprt_destroy_all()
are always invoked in pairs, we can deduplicate code by moving
the svc_rpcb_cleanup() call sites into svc_xprt_destroy_all().

Tested-by: Olga Kornievskaia 
Signed-off-by: Chuck Lever

lockd: Remove space before newline

2025-09-21T23:24:50+00:00

There is an extraneous space before a newline in a dprintk message.
Remove the space.

Signed-off-by: Colin Ian King 
Signed-off-by: Chuck Lever

sysctl: Fixes nsm_local_state bounds

2025-03-10T13:11:13+00:00

Bound nsm_local_state sysctl writings between SYSCTL_ZERO
and SYSCTL_INT_MAX.

The proc_handler has thus been updated to proc_dointvec_minmax.

Signed-off-by: Nicolas Bouchinet 
[ cel: updated to handle zero - UINT_MAX instead ]
Signed-off-by: Chuck Lever

lockd: add netlink control interface

2025-03-10T13:10:53+00:00

The legacy rpc.nfsd tool will set the nlm_grace_period if the NFSv4
grace period is set. nfsdctl is missing this functionality, so add a new
netlink control interface for lockd that it can use. For now, it only
allows setting the grace period, and the tcp and udp listener ports.

lockd currently uses module parameters and sysctls for configuration, so
all of its settings are global. With this change, lockd now tracks these
values on a per-net-ns basis. It will only fall back to using the global
values if any of them are 0.

Finally, as a backward compatibility measure, if updating the nlm
settings in the init_net namespace, also update the legacy global
values to match.

Link: https://issues.redhat.com/browse/RHEL-71698
Signed-off-by: Jeff Layton 
Signed-off-by: Chuck Lever

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
    virtual patch

    @
    depends on !(file in "net")
    disable optional_qualifier
    @

    identifier table_name != {
      watchdog_hardlockup_sysctl,
      iwcm_ctl_table,
      ucma_ctl_table,
      memory_allocation_profiling_sysctls,
      loadpin_sysctl_table
    };
    @@

    + const
    struct ctl_table table_name [] = { ... };

sed:
    sed --in-place \
      -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
      kernel/utsname_sysctl.c

Reviewed-by: Song Liu 
Acked-by: Steven Rostedt (Google)  # for kernel/trace/
Reviewed-by: Martin K. Petersen  # SCSI
Reviewed-by: Darrick J. Wong  # xfs
Acked-by: Jani Nikula 
Acked-by: Corey Minyard 
Acked-by: Wei Liu 
Acked-by: Thomas Gleixner 
Reviewed-by: Bill O'Donnell 
Acked-by: Baoquan He 
Acked-by: Ashutosh Dixit 
Acked-by: Anna Schumaker 
Signed-off-by: Joel Granados

sunrpc: remove all connection limit configuration

2025-01-06T14:37:36+00:00

Now that the connection limit only apply to unconfirmed connections,
there is no need to configure it.  So remove all the configuration and
fix the number of unconfirmed connections as always 64 - which is
now given a name: XPT_MAX_TMP_CONN

Signed-off-by: NeilBrown 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever