Commit graph

4,106 commits

Author SHA1 Message Date
NeilBrown
b186b36a7c nfsd: restore callback functionality for NFSv4.0
[ Upstream commit 7917f01a28 ]

A recent patch inadvertently broke callbacks for NFSv4.0.

In the 4.0 case we do not expect a session to be found but still need to
call setup_callback_client() which will not try to dereference it.

This patch moves the check for failure to find a session into the 4.1+
branch of setup_callback_client()

Fixes: 1e02c641c3 ("NFSD: Prevent NULL dereference in nfsd4_process_cb_update()")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02 10:34:11 +01:00
Yang Erkun
7b005cff0d nfsd: Revert "nfsd: release svc_expkey/svc_export with rcu_work"
[ Upstream commit 69d803c40e ]

This reverts commit f8c989a0c8.

Before this commit, svc_export_put or expkey_put will call path_put with
sync mode. After this commit, path_put will be called with async mode.
And this can lead the unexpected results show as follow.

mkfs.xfs -f /dev/sda
echo "/ *(rw,no_root_squash,fsid=0)" > /etc/exports
echo "/mnt *(rw,no_root_squash,fsid=1)" >> /etc/exports
exportfs -ra
service nfs-server start
mount -t nfs -o vers=4.0 127.0.0.1:/mnt /mnt1
mount /dev/sda /mnt/sda
touch /mnt1/sda/file
exportfs -r
umount /mnt/sda # failed unexcepted

The touch will finally call nfsd_cross_mnt, add refcount to mount, and
then add cache_head. Before this commit, exportfs -r will call
cache_flush to cleanup all cache_head, and path_put in
svc_export_put/expkey_put will be finished with sync mode. So, the
latter umount will always success. However, after this commit, path_put
will be called with async mode, the latter umount may failed, and if
we add some delay, umount will success too. Personally I think this bug
and should be fixed. We first revert before bugfix patch, and then fix
the original bug with a different way.

Fixes: f8c989a0c8 ("nfsd: release svc_expkey/svc_export with rcu_work")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-02 10:34:11 +01:00
Yang Erkun
6f73f920b7 nfsd: fix nfs4_openowner leak when concurrent nfsd4_open occur
commit 98100e88dd upstream.

The action force umount(umount -f) will attempt to kill all rpc_task even
umount operation may ultimately fail if some files remain open.
Consequently, if an action attempts to open a file, it can potentially
send two rpc_task to nfs server.

                   NFS CLIENT
thread1                             thread2
open("file")
...
nfs4_do_open
 _nfs4_do_open
  _nfs4_open_and_get_state
   _nfs4_proc_open
    nfs4_run_open_task
     /* rpc_task1 */
     rpc_run_task
     rpc_wait_for_completion_task

                                    umount -f
                                    nfs_umount_begin
                                     rpc_killall_tasks
                                      rpc_signal_task
     rpc_task1 been wakeup
     and return -512
 _nfs4_do_open // while loop
    ...
    nfs4_run_open_task
     /* rpc_task2 */
     rpc_run_task
     rpc_wait_for_completion_task

While processing an open request, nfsd will first attempt to find or
allocate an nfs4_openowner. If it finds an nfs4_openowner that is not
marked as NFS4_OO_CONFIRMED, this nfs4_openowner will released. Since
two rpc_task can attempt to open the same file simultaneously from the
client to server, and because two instances of nfsd can run
concurrently, this situation can lead to lots of memory leak.
Additionally, when we echo 0 to /proc/fs/nfsd/threads, warning will be
triggered.

                    NFS SERVER
nfsd1                  nfsd2       echo 0 > /proc/fs/nfsd/threads

nfsd4_open
 nfsd4_process_open1
  find_or_alloc_open_stateowner
   // alloc oo1, stateid1
                       nfsd4_open
                        nfsd4_process_open1
                        find_or_alloc_open_stateowner
                        // find oo1, without NFS4_OO_CONFIRMED
                         release_openowner
                          unhash_openowner_locked
                          list_del_init(&oo->oo_perclient)
                          // cannot find this oo
                          // from client, LEAK!!!
                         alloc_stateowner // alloc oo2

 nfsd4_process_open2
  init_open_stateid
  // associate oo1
  // with stateid1, stateid1 LEAK!!!
  nfs4_get_vfs_file
  // alloc nfsd_file1 and nfsd_file_mark1
  // all LEAK!!!

                         nfsd4_process_open2
                         ...

                                    write_threads
                                     ...
                                     nfsd_destroy_serv
                                      nfsd_shutdown_net
                                       nfs4_state_shutdown_net
                                        nfs4_state_destroy_net
                                         destroy_client
                                          __destroy_client
                                          // won't find oo1!!!
                                     nfsd_shutdown_generic
                                      nfsd_file_cache_shutdown
                                       kmem_cache_destroy
                                       for nfsd_file_slab
                                       and nfsd_file_mark_slab
                                       // bark since nfsd_file1
                                       // and nfsd_file_mark1
                                       // still alive

=======================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
-----------------------------------------------------------------------

Slab 0xffd4000004438a80 objects=34 used=1 fp=0xff11000110e2ad28
flags=0x17ffffc0000240(workingset|head|node=0|zone=2|lastcpupid=0x1fffff)
CPU: 4 UID: 0 PID: 757 Comm: sh Not tainted 6.12.0-rc6+ #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x53/0x70
 slab_err+0xb0/0xf0
 __kmem_cache_shutdown+0x15c/0x310
 kmem_cache_destroy+0x66/0x160
 nfsd_file_cache_shutdown+0xac/0x210 [nfsd]
 nfsd_destroy_serv+0x251/0x2a0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1ae/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Disabling lock debugging due to kernel taint
Object 0xff11000110e2ac38 @offset=3128
Allocated in nfsd_file_do_acquire+0x20f/0xa30 [nfsd] age=1635 cpu=3
pid=800
 nfsd_file_do_acquire+0x20f/0xa30 [nfsd]
 nfsd_file_acquire_opened+0x5f/0x90 [nfsd]
 nfs4_get_vfs_file+0x4c9/0x570 [nfsd]
 nfsd4_process_open2+0x713/0x1070 [nfsd]
 nfsd4_open+0x74b/0x8b0 [nfsd]
 nfsd4_proc_compound+0x70b/0xc20 [nfsd]
 nfsd_dispatch+0x1b4/0x3a0 [nfsd]
 svc_process_common+0x5b8/0xc50 [sunrpc]
 svc_process+0x2ab/0x3b0 [sunrpc]
 svc_handle_xprt+0x681/0xa20 [sunrpc]
 nfsd+0x183/0x220 [nfsd]
 kthread+0x199/0x1e0
 ret_from_fork+0x31/0x60
 ret_from_fork_asm+0x1a/0x30

Add nfs4_openowner_unhashed to help found unhashed nfs4_openowner, and
break nfsd4_open process to fix this problem.

Cc: stable@vger.kernel.org # v5.4+
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:41:09 +01:00
Yang Erkun
7365d1f8de nfsd: make sure exp active before svc_export_show
commit be8f982c36 upstream.

The function `e_show` was called with protection from RCU. This only
ensures that `exp` will not be freed. Therefore, the reference count for
`exp` can drop to zero, which will trigger a refcount use-after-free
warning when `exp_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `exp` remains active.

------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 819 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120
...
Call Trace:
 <TASK>
 e_show+0x20b/0x230 [nfsd]
 seq_read_iter+0x589/0x770
 seq_read+0x1e5/0x270
 vfs_read+0x125/0x530
 ksys_read+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: bf18f163e8 ("NFSD: Using exp_get for export getting")
Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:41:09 +01:00
Chuck Lever
ccd3394f9a NFSD: Prevent a potential integer overflow
commit 7f33b92e5b upstream.

If the tag length is >= U32_MAX - 3 then the "length + 4" addition
can result in an integer overflow. Address this by splitting the
decoding into several steps so that decode_cb_compound4res() does
not have to perform arithmetic on the unsafe length value.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-05 14:03:02 +01:00
Mike Snitzer
3e6e3e97d6 nfs_common: must not hold RCU while calling nfsd_file_put_local
[ Upstream commit c840b8e1f0 ]

Move holding the RCU from nfs_to_nfsd_file_put_local to
nfs_to_nfsd_net_put.  It is the call to nfs_to->nfsd_serv_put that
requires the RCU anyway (the puts for nfsd_file and netns were
combined to avoid an extra indirect reference but that
micro-optimization isn't possible now).

This fixes xfstests generic/013 and it triggering:

"Voluntary context switch within RCU read-side critical section!"

[  143.545738] Call Trace:
[  143.546206]  <TASK>
[  143.546625]  ? show_regs+0x6d/0x80
[  143.547267]  ? __warn+0x91/0x140
[  143.547951]  ? rcu_note_context_switch+0x496/0x5d0
[  143.548856]  ? report_bug+0x193/0x1a0
[  143.549557]  ? handle_bug+0x63/0xa0
[  143.550214]  ? exc_invalid_op+0x1d/0x80
[  143.550938]  ? asm_exc_invalid_op+0x1f/0x30
[  143.551736]  ? rcu_note_context_switch+0x496/0x5d0
[  143.552634]  ? wakeup_preempt+0x62/0x70
[  143.553358]  __schedule+0xaa/0x1380
[  143.554025]  ? _raw_spin_unlock_irqrestore+0x12/0x40
[  143.554958]  ? try_to_wake_up+0x1fe/0x6b0
[  143.555715]  ? wake_up_process+0x19/0x20
[  143.556452]  schedule+0x2e/0x120
[  143.557066]  schedule_preempt_disabled+0x19/0x30
[  143.557933]  rwsem_down_read_slowpath+0x24d/0x4a0
[  143.558818]  ? xfs_efi_item_format+0x50/0xc0 [xfs]
[  143.559894]  down_read+0x4e/0xb0
[  143.560519]  xlog_cil_commit+0x1b2/0xbc0 [xfs]
[  143.561460]  ? _raw_spin_unlock+0x12/0x30
[  143.562212]  ? xfs_inode_item_precommit+0xc7/0x220 [xfs]
[  143.563309]  ? xfs_trans_run_precommits+0x69/0xd0 [xfs]
[  143.564394]  __xfs_trans_commit+0xb5/0x330 [xfs]
[  143.565367]  xfs_trans_roll+0x48/0xc0 [xfs]
[  143.566262]  xfs_defer_trans_roll+0x57/0x100 [xfs]
[  143.567278]  xfs_defer_finish_noroll+0x27a/0x490 [xfs]
[  143.568342]  xfs_defer_finish+0x1a/0x80 [xfs]
[  143.569267]  xfs_bunmapi_range+0x4d/0xb0 [xfs]
[  143.570208]  xfs_itruncate_extents_flags+0x13d/0x230 [xfs]
[  143.571353]  xfs_free_eofblocks+0x12e/0x190 [xfs]
[  143.572359]  xfs_file_release+0x12d/0x140 [xfs]
[  143.573324]  __fput+0xe8/0x2d0
[  143.573922]  __fput_sync+0x1d/0x30
[  143.574574]  nfsd_filp_close+0x33/0x60 [nfsd]
[  143.575430]  nfsd_file_free+0x96/0x150 [nfsd]
[  143.576274]  nfsd_file_put+0xf7/0x1a0 [nfsd]
[  143.577104]  nfsd_file_put_local+0x18/0x30 [nfsd]
[  143.578070]  nfs_close_local_fh+0x101/0x110 [nfs_localio]
[  143.579079]  __put_nfs_open_context+0xc9/0x180 [nfs]
[  143.580031]  nfs_file_clear_open_context+0x4a/0x60 [nfs]
[  143.581038]  nfs_file_release+0x3e/0x60 [nfs]
[  143.581879]  __fput+0xe8/0x2d0
[  143.582464]  __fput_sync+0x1d/0x30
[  143.583108]  __x64_sys_close+0x41/0x80
[  143.583823]  x64_sys_call+0x189a/0x20d0
[  143.584552]  do_syscall_64+0x64/0x170
[  143.585240]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  143.586185] RIP: 0033:0x7f3c5153efd7

Fixes: 65f2a5c366 ("nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:27 +01:00
Chuck Lever
9e7c4cfdf7 NFSD: Fix nfsd4_shutdown_copy()
[ Upstream commit 62a8642ba0 ]

nfsd4_shutdown_copy() is just this:

	while ((copy = nfsd4_get_copy(clp)) != NULL)
		nfsd4_stop_copy(copy);

nfsd4_get_copy() bumps @copy's reference count, preventing
nfsd4_stop_copy() from releasing @copy.

A while loop like this usually works by removing the first element
of the list, but neither nfsd4_get_copy() nor nfsd4_stop_copy()
alters the async_copies list.

Best I can tell, then, is that nfsd4_shutdown_copy() continues to
loop until other threads manage to remove all the items from this
list. The spinning loop blocks shutdown until these items are gone.

Possibly the reason we haven't seen this issue in the field is
because client_has_state() prevents __destroy_client() from calling
nfsd4_shutdown_copy() if there are any items on this list. In a
subsequent patch I plan to remove that restriction.

Fixes: e0639dc580 ("NFSD introduce async copy feature")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:26 +01:00
Yang Erkun
ad4363a24a nfsd: release svc_expkey/svc_export with rcu_work
[ Upstream commit f8c989a0c8 ]

The last reference for `cache_head` can be reduced to zero in `c_show`
and `e_show`(using `rcu_read_lock` and `rcu_read_unlock`). Consequently,
`svc_export_put` and `expkey_put` will be invoked, leading to two
issues:

1. The `svc_export_put` will directly free ex_uuid. However,
   `e_show`/`c_show` will access `ex_uuid` after `cache_put`, which can
   trigger a use-after-free issue, shown below.

   ==================================================================
   BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd]
   Read of size 1 at addr ff11000010fdc120 by task cat/870

   CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
   1.16.1-2.fc37 04/01/2014
   Call Trace:
    <TASK>
    dump_stack_lvl+0x53/0x70
    print_address_description.constprop.0+0x2c/0x3a0
    print_report+0xb9/0x280
    kasan_report+0xae/0xe0
    svc_export_show+0x362/0x430 [nfsd]
    c_show+0x161/0x390 [sunrpc]
    seq_read_iter+0x589/0x770
    seq_read+0x1e5/0x270
    proc_reg_read+0xe1/0x140
    vfs_read+0x125/0x530
    ksys_read+0xc1/0x160
    do_syscall_64+0x5f/0x170
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

   Allocated by task 830:
    kasan_save_stack+0x20/0x40
    kasan_save_track+0x14/0x30
    __kasan_kmalloc+0x8f/0xa0
    __kmalloc_node_track_caller_noprof+0x1bc/0x400
    kmemdup_noprof+0x22/0x50
    svc_export_parse+0x8a9/0xb80 [nfsd]
    cache_do_downcall+0x71/0xa0 [sunrpc]
    cache_write_procfs+0x8e/0xd0 [sunrpc]
    proc_reg_write+0xe1/0x140
    vfs_write+0x1a5/0x6d0
    ksys_write+0xc1/0x160
    do_syscall_64+0x5f/0x170
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

   Freed by task 868:
    kasan_save_stack+0x20/0x40
    kasan_save_track+0x14/0x30
    kasan_save_free_info+0x3b/0x60
    __kasan_slab_free+0x37/0x50
    kfree+0xf3/0x3e0
    svc_export_put+0x87/0xb0 [nfsd]
    cache_purge+0x17f/0x1f0 [sunrpc]
    nfsd_destroy_serv+0x226/0x2d0 [nfsd]
    nfsd_svc+0x125/0x1e0 [nfsd]
    write_threads+0x16a/0x2a0 [nfsd]
    nfsctl_transaction_write+0x74/0xa0 [nfsd]
    vfs_write+0x1a5/0x6d0
    ksys_write+0xc1/0x160
    do_syscall_64+0x5f/0x170
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

2. We cannot sleep while using `rcu_read_lock`/`rcu_read_unlock`.
   However, `svc_export_put`/`expkey_put` will call path_put, which
   subsequently triggers a sleeping operation due to the following
   `dput`.

   =============================
   WARNING: suspicious RCU usage
   5.10.0-dirty #141 Not tainted
   -----------------------------
   ...
   Call Trace:
   dump_stack+0x9a/0xd0
   ___might_sleep+0x231/0x240
   dput+0x39/0x600
   path_put+0x1b/0x30
   svc_export_put+0x17/0x80
   e_show+0x1c9/0x200
   seq_read_iter+0x63f/0x7c0
   seq_read+0x226/0x2d0
   vfs_read+0x113/0x2c0
   ksys_read+0xc9/0x170
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x67/0xd1

Fix these issues by using `rcu_work` to help release
`svc_expkey`/`svc_export`. This approach allows for an asynchronous
context to invoke `path_put` and also facilitates the freeing of
`uuid/exp/key` after an RCU grace period.

Fixes: 9ceddd9da1 ("knfsd: Allow lockless lookups of the exports")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:26 +01:00
Chuck Lever
f063b03b81 NFSD: Cap the number of bytes copied by nfs4_reset_recoverydir()
[ Upstream commit f64ea4af43 ]

It's only current caller already length-checks the string, but let's
be safe.

Fixes: 0964a3d3f1 ("[PATCH] knfsd: nfsd4 reboot dirname fix")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:26 +01:00
Chuck Lever
4a4ffc1aa9 NFSD: Prevent NULL dereference in nfsd4_process_cb_update()
[ Upstream commit 1e02c641c3 ]

@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no
available backchannel session, setup_callback_client() will try to
dereference @ses and segfault.

Fixes: dcbeaa68db ("nfsd4: allow backchannel recovery")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:26 +01:00
Jeff Layton
38795ff45c nfsd: drop inode parameter from nfsd4_change_attribute()
[ Upstream commit f67eef8da0 ]

The inode that nfs4_open_delegation() passes to this function is
wrong, which throws off the result. The inode will end up getting a
directory-style change attr instead of a regular-file-style one.

Fix up nfs4_delegation_stat() to fetch STATX_MODE, and then drop the
inode parameter from nfsd4_change_attribute(), since it's no longer
needed.

Fixes: c5967721e1 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:02:24 +01:00
Linus Torvalds
de2f378f2b nfsd-6.12 fixes:
- Fix a v6.12-rc regression when exporting ext4 filesystems with NFSD
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Merge tag 'nfsd-6.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fix from Chuck Lever:

 - Fix a v6.12-rc regression when exporting ext4 filesystems with NFSD

* tag 'nfsd-6.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: Fix READDIR on NFSv3 mounts of ext4 exports
2024-11-09 13:18:07 -08:00
Chuck Lever
bb1fb40f8b NFSD: Fix READDIR on NFSv3 mounts of ext4 exports
I noticed that recently, simple operations like "make" started
failing on NFSv3 mounts of ext4 exports. Network capture shows that
READDIRPLUS operated correctly but READDIR failed with
NFS3ERR_INVAL. The vfs_llseek() call returned EINVAL when it is
passed a non-zero starting directory cookie.

I bisected to commit c689bdd3bf ("nfsd: further centralize
protocol version checks.").

Turns out that nfsd3_proc_readdir() does not call fh_verify() before
it calls nfsd_readdir(), so the new fhp->fh_64bit_cookies boolean is
not set properly. This leaves the NFSD_MAY_64BIT_COOKIE unset when
the directory is opened.

For ext4, this causes the wrong "max file size" value to be used
when sanity checking the incoming directory cookie (which is a seek
offset value).

The fhp->fh_64bit_cookies boolean is /always/ properly initialized
after nfsd_open() returns. There doesn't seem to be a reason for the
generic NFSD open helper to handle the f_mode fix-up for
directories, so just move that to the one caller that tries to open
an S_IFDIR with NFSD_MAY_64BIT_COOKIE.

Suggested-by: NeilBrown <neilb@suse.de>
Fixes: c689bdd3bf ("nfsd: further centralize protocol version checks.")
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-07 09:11:37 -05:00
Linus Torvalds
3e5e6c9900 nfsd-6.12 fixes:
- Fix two async COPY bugs found during NFS bake-a-thon
 - Fix an svcrdma memory leak
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Merge tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Fix two async COPY bugs found during NFS bake-a-thon

 - Fix an svcrdma memory leak

* tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  rpcrdma: Always release the rpcrdma_device's xa_array
  NFSD: Never decrement pending_async_copies on error
  NFSD: Initialize struct nfsd4_copy earlier
2024-11-02 09:27:11 -10:00
Chuck Lever
8286f8b622 NFSD: Never decrement pending_async_copies on error
The error flow in nfsd4_copy() calls cleanup_async_copy(), which
already decrements nn->pending_async_copies.

Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-30 14:12:16 -04:00
Chuck Lever
63fab04cbd NFSD: Initialize struct nfsd4_copy earlier
Ensure the refcount and async_copies fields are initialized early.
cleanup_async_copy() will reference these fields if an error occurs
in nfsd4_copy(). If they are not correctly initialized, at the very
least, a refcount underflow occurs.

Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-29 15:31:18 -04:00
Linus Torvalds
f647053312 nfsd-6.12 fixes:
- Fix a couple of use-after-free bugs
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Merge tag 'nfsd-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Fix a couple of use-after-free bugs

* tag 'nfsd-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net
  nfsd: fix race between laundromat and free_stateid
2024-10-25 11:38:15 -07:00
Yang Erkun
d5ff2fb2e7 nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net
In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the
function `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will
release all resources related to the hashed `nfs4_client`. If the
`nfsd_client_shrinker` is running concurrently, the `expire_client`
function will first unhash this client and then destroy it. This can
lead to the following warning. Additionally, numerous use-after-free
errors may occur as well.

nfsd_client_shrinker         echo 0 > /proc/fs/nfsd/threads

expire_client                nfsd_shutdown_net
  unhash_client                ...
                               nfs4_state_shutdown_net
                                 /* won't wait shrinker exit */
  /*                             cancel_work(&nn->nfsd_shrinker_work)
   * nfsd_file for this          /* won't destroy unhashed client1 */
   * client1 still alive         nfs4_state_destroy_net
   */

                               nfsd_file_cache_shutdown
                                 /* trigger warning */
                                 kmem_cache_destroy(nfsd_file_slab)
                                 kmem_cache_destroy(nfsd_file_mark_slab)
  /* release nfsd_file and mark */
  __destroy_client

====================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
--------------------------------------------------------------------
CPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1

 dump_stack_lvl+0x53/0x70
 slab_err+0xb0/0xf0
 __kmem_cache_shutdown+0x15c/0x310
 kmem_cache_destroy+0x66/0x160
 nfsd_file_cache_shutdown+0xac/0x210 [nfsd]
 nfsd_destroy_serv+0x251/0x2a0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

====================================================================
BUG nfsd_file_mark (Tainted: G    B   W         ): Objects remaining
nfsd_file_mark on __kmem_cache_shutdown()
--------------------------------------------------------------------

 dump_stack_lvl+0x53/0x70
 slab_err+0xb0/0xf0
 __kmem_cache_shutdown+0x15c/0x310
 kmem_cache_destroy+0x66/0x160
 nfsd_file_cache_shutdown+0xc8/0x210 [nfsd]
 nfsd_destroy_serv+0x251/0x2a0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

To resolve this issue, cancel `nfsd_shrinker_work` using synchronous
mode in nfs4_state_shutdown_net.

Fixes: 7c24fa2250 ("NFSD: replace delayed_work with work_struct for nfsd_client_shrinker")
Signed-off-by: Yang Erkun <yangerkun@huaweicloud.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-21 10:27:36 -04:00
Olga Kornievskaia
8dd91e8d31 nfsd: fix race between laundromat and free_stateid
There is a race between laundromat handling of revoked delegations
and a client sending free_stateid operation. Laundromat thread
finds that delegation has expired and needs to be revoked so it
marks the delegation stid revoked and it puts it on a reaper list
but then it unlock the state lock and the actual delegation revocation
happens without the lock. Once the stid is marked revoked a racing
free_stateid processing thread does the following (1) it calls
list_del_init() which removes it from the reaper list and (2) frees
the delegation stid structure. The laundromat thread ends up not
calling the revoke_delegation() function for this particular delegation
but that means it will no release the lock lease that exists on
the file.

Now, a new open for this file comes in and ends up finding that
lease list isn't empty and calls nfsd_breaker_owns_lease() which ends
up trying to derefence a freed delegation stateid. Leading to the
followint use-after-free KASAN warning:

kernel: ==================================================================
kernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd]
kernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205
kernel:
kernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9
kernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024
kernel: Call trace:
kernel: dump_backtrace+0x98/0x120
kernel: show_stack+0x1c/0x30
kernel: dump_stack_lvl+0x80/0xe8
kernel: print_address_description.constprop.0+0x84/0x390
kernel: print_report+0xa4/0x268
kernel: kasan_report+0xb4/0xf8
kernel: __asan_report_load8_noabort+0x1c/0x28
kernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd]
kernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd]
kernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd]
kernel: nfs4_get_vfs_file+0x634/0x958 [nfsd]
kernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd]
kernel: nfsd4_open+0xa08/0xe80 [nfsd]
kernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd]
kernel: nfsd_dispatch+0x22c/0x718 [nfsd]
kernel: svc_process_common+0x8e8/0x1960 [sunrpc]
kernel: svc_process+0x3d4/0x7e0 [sunrpc]
kernel: svc_handle_xprt+0x828/0xe10 [sunrpc]
kernel: svc_recv+0x2cc/0x6a8 [sunrpc]
kernel: nfsd+0x270/0x400 [nfsd]
kernel: kthread+0x288/0x310
kernel: ret_from_fork+0x10/0x20

This patch proposes a fixed that's based on adding 2 new additional
stid's sc_status values that help coordinate between the laundromat
and other operations (nfsd4_free_stateid() and nfsd4_delegreturn()).

First to make sure, that once the stid is marked revoked, it is not
removed by the nfsd4_free_stateid(), the laundromat take a reference
on the stateid. Then, coordinating whether the stid has been put
on the cl_revoked list or we are processing FREE_STATEID and need to
make sure to remove it from the list, each check that state and act
accordingly. If laundromat has added to the cl_revoke list before
the arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove
it from the list. If nfsd4_free_stateid() finds that operations arrived
before laundromat has placed it on cl_revoke list, it marks the state
freed and then laundromat will no longer add it to the list.

Also, for nfsd4_delegreturn() when looking for the specified stid,
we need to access stid that are marked removed or freeable, it means
the laundromat has started processing it but hasn't finished and this
delegreturn needs to return nfserr_deleg_revoked and not
nfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the
lack of it will leave this stid on the cl_revoked list indefinitely.

Fixes: 2d4a532d38 ("nfsd: ensure that clp->cl_revoked list is protected by clp->cl_lock")
CC: stable@vger.kernel.org
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-18 16:40:37 -04:00
Linus Torvalds
6254d53727 NFS Client Bugfixes for Linux 6.12-rc
Localio Bugfixes:
   * Remove duplicated include in localio.c
   * Fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
   * Fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
   * Fix nfsd_file tracepoints to handle NULL rqstp pointers
 
 Other Bugfixes:
   * Fix program selection loop in svc_process_common
   * Fix integer overflow in decode_rc_list()
   * Prevent NULL-pointer dereference in nfs42_complete_copies()
   * Fix CB_RECALL performance issues when using a large number of delegations
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Merge tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client fixes from Anna Schumaker:
 "Localio Bugfixes:
   - remove duplicated include in localio.c
   - fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
   - fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
   - fix nfsd_file tracepoints to handle NULL rqstp pointers

  Other Bugfixes:
   - fix program selection loop in svc_process_common
   - fix integer overflow in decode_rc_list()
   - prevent NULL-pointer dereference in nfs42_complete_copies()
   - fix CB_RECALL performance issues when using a large number of
     delegations"

* tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFS: remove revoked delegation from server's delegation list
  nfsd/localio: fix nfsd_file tracepoints to handle NULL rqstp
  nfs_common: fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT
  nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
  NFSv4: Prevent NULL-pointer dereference in nfs42_complete_copies()
  SUNRPC: Fix integer overflow in decode_rc_list()
  sunrpc: fix prog selection loop in svc_process_common
  nfs: Remove duplicated include in localio.c
2024-10-11 15:37:15 -07:00
Linus Torvalds
5870963f6c nfsd-6.12 fixes:
- Fix NFSD bring-up / shutdown
 - Fix a UAF when releasing a stateid
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Merge tag 'nfsd-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Fix NFSD bring-up / shutdown

 - Fix a UAF when releasing a stateid

* tag 'nfsd-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: fix possible badness in FREE_STATEID
  nfsd: nfsd_destroy_serv() must call svc_destroy() even if nfsd_startup_net() failed
  NFSD: Mark filecache "down" if init fails
2024-10-10 09:52:49 -07:00
Olga Kornievskaia
c88c150a46 nfsd: fix possible badness in FREE_STATEID
When multiple FREE_STATEIDs are sent for the same delegation stateid,
it can lead to a possible either use-after-free or counter refcount
underflow errors.

In nfsd4_free_stateid() under the client lock we find a delegation
stateid, however the code drops the lock before calling nfs4_put_stid(),
that allows another FREE_STATE to find the stateid again. The first one
will proceed to then free the stateid which leads to either
use-after-free or decrementing already zeroed counter.

Fixes: 3f29cc82a8 ("nfsd: split sc_status out of sc_type")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-05 15:44:25 -04:00
Mike Snitzer
76f5af9952 nfsd/localio: fix nfsd_file tracepoints to handle NULL rqstp
Otherwise nfsd_file_acquire, nfsd_file_insert_err, and
nfsd_file_cons_err will hit a NULL pointer when they are enabled and
LOCALIO used.

Example trace output (note xid is 0x0 and LOCALIO flag set):
 nfsd_file_acquire: xid=0x0 inode=0000000069a1b2e7
 may_flags=WRITE|LOCALIO ref=1 nf_flags=HASHED|GC nf_may=WRITE
 nf_file=0000000070123234 status=0

Fixes: c63f0e48fe ("nfsd: add nfsd_file_acquire_local()")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-10-04 14:52:04 -04:00
Mike Snitzer
65f2a5c366 nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()
Add nfs_to_nfsd_file_put_local() interface to fix race with nfsd
module unload.  Similarly, use RCU around nfs_open_local_fh()'s error
path call to nfs_to->nfsd_serv_put().  Holding RCU ensures that NFS
will safely _call and return_ from its nfs_to calls into the NFSD
functions nfsd_file_put_local() and nfsd_serv_put().

Otherwise, if RCU isn't used then there is a narrow window when NFS's
reference for the nfsd_file and nfsd_serv are dropped and the NFSD
module could be unloaded, which could result in a crash from the
return instruction for either nfs_to->nfsd_file_put_local() or
nfs_to->nfsd_serv_put().

Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-10-03 16:19:43 -04:00
Lizhi Xu
cad3f4a22c inotify: Fix possible deadlock in fsnotify_destroy_mark
[Syzbot reported]
WARNING: possible circular locking dependency detected
6.11.0-rc4-syzkaller-00019-gb311c1b497e5 #0 Not tainted
------------------------------------------------------
kswapd0/78 is trying to acquire lock:
ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline]
ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578

but task is already holding lock:
ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6841 [inline]
ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbb4/0x35a0 mm/vmscan.c:7223

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
       ...
       kmem_cache_alloc_noprof+0x3d/0x2a0 mm/slub.c:4044
       inotify_new_watch fs/notify/inotify/inotify_user.c:599 [inline]
       inotify_update_watch fs/notify/inotify/inotify_user.c:647 [inline]
       __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:786 [inline]
       __se_sys_inotify_add_watch+0x72e/0x1070 fs/notify/inotify/inotify_user.c:729
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&group->mark_mutex){+.+.}-{3:3}:
       ...
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline]
       fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578
       fsnotify_destroy_marks+0x14a/0x660 fs/notify/mark.c:934
       fsnotify_inoderemove include/linux/fsnotify.h:264 [inline]
       dentry_unlink_inode+0x2e0/0x430 fs/dcache.c:403
       __dentry_kill+0x20d/0x630 fs/dcache.c:610
       shrink_kill+0xa9/0x2c0 fs/dcache.c:1055
       shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1082
       prune_dcache_sb+0x10f/0x180 fs/dcache.c:1163
       super_cache_scan+0x34f/0x4b0 fs/super.c:221
       do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
       shrink_slab+0x1093/0x14d0 mm/shrinker.c:662
       shrink_one+0x43b/0x850 mm/vmscan.c:4815
       shrink_many mm/vmscan.c:4876 [inline]
       lru_gen_shrink_node mm/vmscan.c:4954 [inline]
       shrink_node+0x3799/0x3de0 mm/vmscan.c:5934
       kswapd_shrink_node mm/vmscan.c:6762 [inline]
       balance_pgdat mm/vmscan.c:6954 [inline]
       kswapd+0x1bcd/0x35a0 mm/vmscan.c:7223

[Analysis]
The problem is that inotify_new_watch() is using GFP_KERNEL to allocate
new watches under group->mark_mutex, however if dentry reclaim races
with unlinking of an inode, it can end up dropping the last dentry reference
for an unlinked inode resulting in removal of fsnotify mark from reclaim
context which wants to acquire group->mark_mutex as well.

This scenario shows that all notification groups are in principle prone
to this kind of a deadlock (previously, we considered only fanotify and
dnotify to be problematic for other reasons) so make sure all
allocations under group->mark_mutex happen with GFP_NOFS.

Reported-and-tested-by: syzbot+c679f13773f295d2da53@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c679f13773f295d2da53
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240927143642.2369508-1-lizhi.xu@windriver.com
2024-10-02 15:14:29 +02:00
Mike Snitzer
946af9b3a0 nfsd: implement server support for NFS_LOCALIO_PROGRAM
The LOCALIO auxiliary RPC protocol consists of a single "UUID_IS_LOCAL"
RPC method that allows the Linux NFS client to verify the local Linux
NFS server can see the nonce (single-use UUID) the client generated and
made available in nfs_common.  The server expects this protocol to use
the same transport as NFS and NFSACL for its RPCs.  This protocol
isn't part of an IETF standard, nor does it need to be considering it
is Linux-to-Linux auxiliary RPC protocol that amounts to an
implementation detail.

The UUID_IS_LOCAL method encodes the client generated uuid_t in terms of
the fixed UUID_SIZE (16 bytes).  The fixed size opaque encode and decode
XDR methods are used instead of the less efficient variable sized
methods.

The RPC program number for the NFS_LOCALIO_PROGRAM is 400122 (as assigned
by IANA, see https://www.iana.org/assignments/rpc-program-numbers/ ):
Linux Kernel Organization       400122  nfslocalio

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
[neilb: factored out and simplified single localio protocol]
Co-developed-by: NeilBrown <neilb@suse.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
Weston Andros Adamson
fa4983862e nfsd: add LOCALIO support
Add server support for bypassing NFS for localhost reads, writes, and
commits. This is only useful when both the client and server are
running on the same host.

If nfsd_open_local_fh() fails then the NFS client will both retry and
fallback to normal network-based read, write and commit operations if
localio is no longer supported.

Care is taken to ensure the same NFS security mechanisms are used
(authentication, etc) regardless of whether localio or regular NFS
access is used.  The auth_domain established as part of the traditional
NFS client access to the NFS server is also used for localio.  Store
auth_domain for localio in nfsd_uuid_t and transfer it to the client
if it is local to the server.

Relative to containers, localio gives the client access to the network
namespace the server has.  This is required to allow the client to
access the server's per-namespace nfsd_net struct.

This commit also introduces the use of NFSD's percpu_ref to interlock
nfsd_destroy_serv and nfsd_open_local_fh, to ensure nn->nfsd_serv is
not destroyed while in use by nfsd_open_local_fh and other LOCALIO
client code.

CONFIG_NFS_LOCALIO enables NFS server support for LOCALIO.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Co-developed-by: NeilBrown <neilb@suse.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
Mike Snitzer
a61e147e6b nfs_common: prepare for the NFS client to use nfsd_file for LOCALIO
The next commit will introduce nfsd_open_local_fh() which returns an
nfsd_file structure.  This commit exposes LOCALIO's required NFSD
symbols to the NFS client:

- Make nfsd_open_local_fh() symbol and other required NFSD symbols
  available to NFS in a global 'nfs_to' nfsd_localio_operations
  struct (global access suggested by Trond, nfsd_localio_operations
  suggested by NeilBrown).  The next commit will also introduce
  nfsd_localio_ops_init() that init_nfsd() will call to initialize
  'nfs_to'.

- Introduce nfsd_file_file() that provides access to nfsd_file's
  backing file.  Keeps nfsd_file structure opaque to NFS client (as
  suggested by Jeff Layton).

- Introduce nfsd_file_put_local() that will put the reference to the
  nfsd_file's associated nn->nfsd_serv and then put the reference to
  the nfsd_file (as suggested by NeilBrown).

Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com> # nfs_to
Suggested-by: NeilBrown <neilb@suse.de> # nfsd_localio_operations
Suggested-by: Jeff Layton <jlayton@kernel.org> # nfsd_file_file
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
86ab08beb3 SUNRPC: replace program list with program array
A service created with svc_create_pooled() can be given a linked list of
programs and all of these will be served.

Using a linked list makes it cumbersome when there are several programs
that can be optionally selected with CONFIG settings.

After this patch is applied, API consumers must use only
svc_create_pooled() when creating an RPC service that listens for more
than one RPC program.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
Mike Snitzer
47e988147f nfsd: add nfsd_serv_try_get and nfsd_serv_put
Introduce nfsd_serv_try_get and nfsd_serv_put and update the nfsd code
to prevent nfsd_destroy_serv from destroying nn->nfsd_serv until any
caller of nfsd_serv_try_get releases their reference using nfsd_serv_put.

A percpu_ref is used to implement the interlock between
nfsd_destroy_serv and any caller of nfsd_serv_try_get.

This interlock is needed to properly wait for the completion of client
initiated localio calls to nfsd (that are _not_ in the context of nfsd).

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
c63f0e48fe nfsd: add nfsd_file_acquire_local()
nfsd_file_acquire_local() can be used to look up a file by filehandle
without having a struct svc_rqst.  This can be used by NFS LOCALIO to
allow the NFS client to bypass the NFS protocol to directly access a
file provided by the NFS server which is running in the same kernel.

In nfsd_file_do_acquire() care is taken to always use fh_verify() if
rqstp is not NULL (as is the case for non-LOCALIO callers).  Otherwise
the non-LOCALIO callers will not supply the correct and required
arguments to __fh_verify (e.g. gssclient isn't passed).

Introduce fh_verify_local() wrapper around __fh_verify to make it
clear that LOCALIO is intended caller.

Also, use GC for nfsd_file returned by nfsd_file_acquire_local.  GC
offers performance improvements if/when a file is reopened before
launderette cleans it from the filecache's LRU.

Suggested-by: Jeff Layton <jlayton@kernel.org> # use filecache's GC
Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
5e66d2d92a nfsd: factor out __fh_verify to allow NULL rqstp to be passed
__fh_verify() offers an interface like fh_verify() but doesn't require
a struct svc_rqst *, instead it also takes the specific parts as
explicit required arguments.  So it is safe to call __fh_verify() with
a NULL rqstp, but the net, cred, and client args must not be NULL.

__fh_verify() does not use SVC_NET(), nor does the functions it calls.

Rather than using rqstp->rq_client pass the client and gssclient
explicitly to __fh_verify and then to nfsd_set_fh_dentry().

Lastly, it should be noted that the previous commit prepared for 4
associated tracepoints to only be used if rqstp is not NULL (this is a
stop-gap that should be properly fixed so localio also benefits from
the utility these tracepoints provide when debugging fh_verify
issues).

Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
Chuck Lever
71c61a0077 NFSD: Short-circuit fh_verify tracepoints for LOCALIO
LOCALIO will be able to call fh_verify() with a NULL rqstp. In this
case, the existing trace points need to be skipped because they
want to dereference the address fields in the passed-in rqstp.

Temporarily make these trace points conditional to avoid a seg
fault in this case. Putting the "rqstp != NULL" check in the trace
points themselves makes the check more efficient.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
Chuck Lever
7c0b07b49b NFSD: Avoid using rqstp->rq_vers in nfsd_set_fh_dentry()
Currently, fh_verify() makes some daring assumptions about which
version of file handle the caller wants, based on the things it can
find in the passed-in rqstp. The about-to-be-introduced LOCALIO use
case sometimes has no svc_rqst context, so this logic won't work in
that case.

Instead, examine the passed-in file handle. It's .max_size field
should carry information to allow nfsd_set_fh_dentry() to initialize
the file handle appropriately.

The file handle used by lockd and the one created by write_filehandle
never need any of the version-specific fields (which affect things
like write and getattr requests and pre/post attributes).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
b0d87dbd8b NFSD: Refactor nfsd_setuser_and_check_port()
There are several places where __fh_verify unconditionally dereferences
rqstp to check that the connection is suitably secure.  They look at
rqstp->rq_xprt which is not meaningful in the target use case of
"localio" NFS in which the client talks directly to the local server.

Prepare these to always succeed when rqstp is NULL.

Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:30 -04:00
NeilBrown
0a183f24a7 NFSD: Handle @rqstp == NULL in check_nfsd_access()
LOCALIO-initiated open operations are not running in an nfsd thread
and thus do not have an associated svc_rqst context.

Signed-off-by: NeilBrown <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:29 -04:00
Mike Snitzer
4806ded4c1 nfs_common: factor out nfs_errtbl and nfs_stat_to_errno
Common nfs_stat_to_errno() is used by both fs/nfs/nfs2xdr.c and
fs/nfs/nfs3xdr.c

Will also be used by fs/nfsd/localio.c

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23 15:03:29 -04:00
NeilBrown
53e4e17557 nfsd: nfsd_destroy_serv() must call svc_destroy() even if nfsd_startup_net() failed
If nfsd_startup_net() fails and so ->nfsd_net_up is false,
nfsd_destroy_serv() doesn't currently call svc_destroy().  It should.

Fixes: 1e3577a452 ("SUNRPC: discard sv_refcnt, and svc_get/svc_put")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-23 10:37:32 -04:00
Chuck Lever
dc0d0f885a NFSD: Mark filecache "down" if init fails
NeilBrown says:
> The handling of NFSD_FILE_CACHE_UP is strange.  nfsd_file_cache_init()
> sets it, but doesn't clear it on failure.  So if nfsd_file_cache_init()
> fails for some reason, nfsd_file_cache_shutdown() would still try to
> clean up if it was called.

Reported-by: NeilBrown <neilb@suse.de>
Fixes: c7b824c3d0 ("NFSD: Replace the "init once" mechanism")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-23 10:37:20 -04:00
NeilBrown
45bb63ed20 nfsd: fix delegation_blocked() to block correctly for at least 30 seconds
The pair of bloom filtered used by delegation_blocked() was intended to
block delegations on given filehandles for between 30 and 60 seconds.  A
new filehandle would be recorded in the "new" bit set.  That would then
be switch to the "old" bit set between 0 and 30 seconds later, and it
would remain as the "old" bit set for 30 seconds.

Unfortunately the code intended to clear the old bit set once it reached
30 seconds old, preparing it to be the next new bit set, instead cleared
the *new* bit set before switching it to be the old bit set.  This means
that the "old" bit set is always empty and delegations are blocked
between 0 and 30 seconds.

This patch updates bd->new before clearing the set with that index,
instead of afterwards.

Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 6282cd5655 ("NFSD: Don't hand out delegations for 30 seconds after recalling them.")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:38 -04:00
Jeff Layton
bf92e5008b nfsd: fix initial getattr on write delegation
At this point in compound processing, currentfh refers to the parent of
the file, not the file itself. Get the correct dentry from the delegation
stateid instead.

Fixes: c5967721e1 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:37 -04:00
NeilBrown
a078a7dc0e nfsd: untangle code in nfsd4_deleg_getattr_conflict()
The code in nfsd4_deleg_getattr_conflict() is convoluted and buggy.

With this patch we:
 - properly handle non-nfsd leases.  We must not assume flc_owner is a
    delegation unless fl_lmops == &nfsd_lease_mng_ops
 - move the main code out of the for loop
 - have a single exit which calls nfs4_put_stid()
   (and other exits which don't need to call that)

[ jlayton: refactored on top of Neil's other patch: nfsd: fix
	   nfsd4_deleg_getattr_conflict in presence of third party lease ]

Fixes: c5967721e1 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:36 -04:00
Scott Mayhew
5559c157b7 nfsd: enforce upper limit for namelen in __cld_pipe_inprogress_downcall()
This patch is intended to go on top of "nfsd: return -EINVAL when
namelen is 0" from Li Lingfeng.  Li's patch checks for 0, but we should
be enforcing an upper bound as well.

Note that if nfsdcld somehow gets an id > NFS4_OPAQUE_LIMIT in its
database, it'll truncate it to NFS4_OPAQUE_LIMIT when it does the
downcall anyway.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:35 -04:00
Li Lingfeng
22451a16b7 nfsd: return -EINVAL when namelen is 0
When we have a corrupted main.sqlite in /var/lib/nfs/nfsdcld/, it may
result in namelen being 0, which will cause memdup_user() to return
ZERO_SIZE_PTR.
When we access the name.data that has been assigned the value of
ZERO_SIZE_PTR in nfs4_client_to_reclaim(), null pointer dereference is
triggered.

[ T1205] ==================================================================
[ T1205] BUG: KASAN: null-ptr-deref in nfs4_client_to_reclaim+0xe9/0x260
[ T1205] Read of size 1 at addr 0000000000000010 by task nfsdcld/1205
[ T1205]
[ T1205] CPU: 11 PID: 1205 Comm: nfsdcld Not tainted 5.10.0-00003-g2c1423731b8d #406
[ T1205] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
[ T1205] Call Trace:
[ T1205]  dump_stack+0x9a/0xd0
[ T1205]  ? nfs4_client_to_reclaim+0xe9/0x260
[ T1205]  __kasan_report.cold+0x34/0x84
[ T1205]  ? nfs4_client_to_reclaim+0xe9/0x260
[ T1205]  kasan_report+0x3a/0x50
[ T1205]  nfs4_client_to_reclaim+0xe9/0x260
[ T1205]  ? nfsd4_release_lockowner+0x410/0x410
[ T1205]  cld_pipe_downcall+0x5ca/0x760
[ T1205]  ? nfsd4_cld_tracking_exit+0x1d0/0x1d0
[ T1205]  ? down_write_killable_nested+0x170/0x170
[ T1205]  ? avc_policy_seqno+0x28/0x40
[ T1205]  ? selinux_file_permission+0x1b4/0x1e0
[ T1205]  rpc_pipe_write+0x84/0xb0
[ T1205]  vfs_write+0x143/0x520
[ T1205]  ksys_write+0xc9/0x170
[ T1205]  ? __ia32_sys_read+0x50/0x50
[ T1205]  ? ktime_get_coarse_real_ts64+0xfe/0x110
[ T1205]  ? ktime_get_coarse_real_ts64+0xa2/0x110
[ T1205]  do_syscall_64+0x33/0x40
[ T1205]  entry_SYSCALL_64_after_hwframe+0x67/0xd1
[ T1205] RIP: 0033:0x7fdbdb761bc7
[ T1205] Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 514
[ T1205] RSP: 002b:00007fff8c4b7248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ T1205] RAX: ffffffffffffffda RBX: 000000000000042b RCX: 00007fdbdb761bc7
[ T1205] RDX: 000000000000042b RSI: 00007fff8c4b75f0 RDI: 0000000000000008
[ T1205] RBP: 00007fdbdb761bb0 R08: 0000000000000000 R09: 0000000000000001
[ T1205] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000042b
[ T1205] R13: 0000000000000008 R14: 00007fff8c4b75f0 R15: 0000000000000000
[ T1205] ==================================================================

Fix it by checking namelen.

Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Fixes: 74725959c3 ("nfsd: un-deprecate nfsdcld")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Scott Mayhew <smayhew@redhat.com>
Tested-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:35 -04:00
Chuck Lever
0505de9615 NFSD: Wrap async copy operations with trace points
Add an nfsd_copy_async_done to record the timestamp, the final
status code, and the callback stateid of an async copy.

Rename the nfsd_copy_do_async tracepoint to match that naming
convention to make it easier to enable both of these with a
single glob.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
Chuck Lever
d3c430aa97 NFSD: Clean up extra whitespace in trace_nfsd_copy_done
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
Chuck Lever
e1d2697c53 NFSD: Record the callback stateid in copy tracepoints
Match COPY operations up with CB_OFFLOAD operations.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
Chuck Lever
11848e985c NFSD: Display copy stateids with conventional print formatting
Make it easier to grep for s2s COPY stateids in trace logs: Use the
same display format in nfsd_copy_class as is used to display other
stateids.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
Chuck Lever
aadc3bbea1 NFSD: Limit the number of concurrent async COPY operations
Nothing appears to limit the number of concurrent async COPY
operations that clients can start. In addition, AFAICT each async
COPY can copy an unlimited number of 4MB chunks, so can run for a
long time. Thus IMO async COPY can become a DoS vector.

Add a restriction mechanism that bounds the number of concurrent
background COPY operations. Start simple and try to be fair -- this
patch implements a per-namespace limit.

An async COPY request that occurs while this limit is exceeded gets
NFS4ERR_DELAY. The requesting client can choose to send the request
again after a delay or fall back to a traditional read/write style
copy.

If there is need to make the mechanism more sophisticated, we can
visit that in future patches.

Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00
Chuck Lever
9ed666eba4 NFSD: Async COPY result needs to return a write verifier
Currently, when NFSD handles an asynchronous COPY, it returns a
zero write verifier, relying on the subsequent CB_OFFLOAD callback
to pass the write verifier and a stable_how4 value to the client.

However, if the CB_OFFLOAD never arrives at the client (for example,
if a network partition occurs just as the server sends the
CB_OFFLOAD operation), the client will never receive this verifier.
Thus, if the client sends a follow-up COMMIT, there is no way for
the client to assess the COMMIT result.

The usual recovery for a missing CB_OFFLOAD is for the client to
send an OFFLOAD_STATUS operation, but that operation does not carry
a write verifier in its result. Neither does it carry a stable_how4
value, so the client /must/ send a COMMIT in this case -- which will
always fail because currently there's still no write verifier in the
COPY result.

Thus the server needs to return a normal write verifier in its COPY
result even if the COPY operation is to be performed asynchronously.

If the server recognizes the callback stateid in subsequent
OFFLOAD_STATUS operations, then obviously it has not restarted, and
the write verifier the client received in the COPY result is still
valid and can be used to assess a COMMIT of the copied data, if one
is needed.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:03 -04:00