commit b31da62889 upstream.
In nfs4_state_start_net(), laundromat_work may access nfsd_ssc through
nfs4_laundromat -> nfsd4_ssc_expire_umount. If nfsd_ssc isn't initialized,
this can cause NULL pointer dereference.
Normally the delayed start of laundromat_work allows sufficient time for
nfsd_ssc initialization to complete. However, when the kernel waits too
long for userspace responses (e.g. in nfs4_state_start_net ->
nfsd4_end_grace -> nfsd4_record_grace_done -> nfsd4_cld_grace_done ->
cld_pipe_upcall -> __cld_pipe_upcall -> wait_for_completion path), the
delayed work may start before nfsd_ssc initialization finishes.
Fix this by moving nfsd_ssc initialization before starting laundromat_work.
Fixes: f4e44b3933 ("NFSD: delay unmount source's export after inter-server copy completed.")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1244f0b2c3 upstream.
If the request being processed is not a v4 compound request, then
examining the cstate can have undefined results.
This patch adds a check that the rpc procedure being executed
(rq_procinfo) is the NFSPROC4_COMPOUND procedure.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a1d14d931b ]
A deadlock warning occurred when invoking nfs4_put_stid following a failed
dl_recall queue operation:
T1 T2
nfs4_laundromat
nfs4_get_client_reaplist
nfs4_anylock_blockers
__break_lease
spin_lock // ctx->flc_lock
spin_lock // clp->cl_lock
nfs4_lockowner_has_blockers
locks_owner_has_blockers
spin_lock // flctx->flc_lock
nfsd_break_deleg_cb
nfsd_break_one_deleg
nfs4_put_stid
refcount_dec_and_lock
spin_lock // clp->cl_lock
When a file is opened, an nfs4_delegation is allocated with sc_count
initialized to 1, and the file_lease holds a reference to the delegation.
The file_lease is then associated with the file through kernel_setlease.
The disassociation is performed in nfsd4_delegreturn via the following
call chain:
nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg -->
nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease
The corresponding sc_count reference will be released after this
disassociation.
Since nfsd_break_one_deleg executes while holding the flc_lock, the
disassociation process becomes blocked when attempting to acquire flc_lock
in generic_delete_lease. This means:
1) sc_count in nfsd_break_one_deleg will not be decremented to 0;
2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to
acquire cl_lock;
3) Consequently, no deadlock condition is created.
Given that sc_count in nfsd_break_one_deleg remains non-zero, we can
safely perform refcount_dec on sc_count directly. This approach
effectively avoids triggering deadlock warnings.
Fixes: 230ca75845 ("nfsd: put dl_stid if fail to queue dl_recall")
Signed-off-by: Li Lingfeng <lilingfeng3@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>
[ Upstream commit cd35b6cb46 ]
nfs.ko, nfsd.ko, and lockd.ko all use crc32_le(), which is available
only when CONFIG_CRC32 is enabled. But the only NFS kconfig option that
selected CONFIG_CRC32 was CONFIG_NFS_DEBUG, which is client-specific and
did not actually guard the use of crc32_le() even on the client.
The code worked around this bug by only actually calling crc32_le() when
CONFIG_CRC32 is built-in, instead hard-coding '0' in other cases. This
avoided randconfig build errors, and in real kernels the fallback code
was unlikely to be reached since CONFIG_CRC32 is 'default y'. But, this
really needs to just be done properly, especially now that I'm planning
to update CONFIG_CRC32 to not be 'default y'.
Therefore, make CONFIG_NFS_FS, CONFIG_NFSD, and CONFIG_LOCKD select
CONFIG_CRC32. Then remove the fallback code that becomes unnecessary,
as well as the selection of CONFIG_CRC32 from CONFIG_NFS_DEBUG.
Fixes: 1264a2f053 ("NFS: refactor code for calculating the crc32 hash of a filehandle")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8a388c1fab upstream.
NFSD sends CB_RECALL_ANY to clients when the server is low on
memory or that client has a large number of delegations outstanding.
We've seen cases where NFSD attempts to send CB_RECALL_ANY requests
to disconnected clients, and gets confused. These calls never go
anywhere if a backchannel transport to the target client isn't
available. Before the server can send any backchannel operation, the
client has to connect first and then do a BIND_CONN_TO_SESSION.
This patch doesn't address the root cause of the confusion, but
there's no need to queue up these optional operations if they can't
go anywhere.
Fixes: 44df6f439a ("NFSD: add delegation reaper to react to low memory condition")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 230ca75845 upstream.
Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we
increment the reference count of dl_stid.
We expect that after the corresponding work_struct is processed, the
reference count of dl_stid will be decremented through the callback
function nfsd4_cb_recall_release.
However, if the call to nfsd4_run_cb fails, the incremented reference
count of dl_stid will not be decremented correspondingly, leading to the
following nfs4_stid leak:
unreferenced object 0xffff88812067b578 (size 344):
comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s)
hex dump (first 32 bytes):
01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........
00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N..
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfsd4_process_open1+0x34/0x300
nfsd4_open+0x2d1/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
unreferenced object 0xffff8881499f4d28 (size 368):
comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I....
30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... .......
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfs4_alloc_stid+0x29/0x210
alloc_init_deleg+0x92/0x2e0
nfs4_set_delegation+0x284/0xc00
nfs4_open_delegation+0x216/0x3f0
nfsd4_process_open2+0x2b3/0xee0
nfsd4_open+0x770/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if
fail to queue dl_recall.
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@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>
commit 036ac2778f upstream.
If nfs4_client is in courtesy state then there is no point to send
the callback. This causes nfsd4_shutdown_callback to hang since
cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP
notifies NFSD that the connection was dropped.
This patch modifies nfsd4_run_cb_work to skip the RPC call if
nfs4_client is in courtesy state.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Fixes: 66af257999 ("NFSD: add courteous server support for thread with only delegation")
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>
commit 961b4b5e86 upstream.
I noticed that once an NFSv4.1 callback operation gets a
NFS4ERR_DELAY status on CB_SEQUENCE and then the connection is lost,
the callback client loops, resending it indefinitely.
The switch arm in nfsd4_cb_sequence_done() that handles
NFS4ERR_DELAY uses rpc_restart_call() to rearm the RPC state machine
for the retransmit, but that path does not call the rpc_prepare_call
callback again. Thus cb_seq_status is set to -10008 by the first
NFS4ERR_DELAY result, but is never set back to 1 for the retransmits.
nfsd4_cb_sequence_done() thinks it's getting nothing but a
long series of CB_SEQUENCE NFS4ERR_DELAY replies.
Fixes: 7ba6cad6c8 ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8e6e2ffa65 upstream.
nfsd_file_put() in one thread can race with another thread doing
garbage collection (running nfsd_file_gc() -> list_lru_walk() ->
nfsd_file_lru_cb()):
* In nfsd_file_put(), nf->nf_ref is 1, so it tries to do nfsd_file_lru_add().
* nfsd_file_lru_add() returns true (with NFSD_FILE_REFERENCED bit set)
* garbage collector kicks in, nfsd_file_lru_cb() clears REFERENCED bit and
returns LRU_ROTATE.
* garbage collector kicks in again, nfsd_file_lru_cb() now decrements nf->nf_ref
to 0, runs nfsd_file_unhash(), removes it from the LRU and adds to the dispose
list [list_lru_isolate_move(lru, &nf->nf_lru, head)]
* nfsd_file_put() detects NFSD_FILE_HASHED bit is cleared, so it tries to remove
the 'nf' from the LRU [if (!nfsd_file_lru_remove(nf))]. The 'nf' has been added
to the 'dispose' list by nfsd_file_lru_cb(), so nfsd_file_lru_remove(nf) simply
treats it as part of the LRU and removes it, which leads to its removal from
the 'dispose' list.
* At this moment, 'nf' is unhashed with its nf_ref being 0, and not on the LRU.
nfsd_file_put() continues its execution [if (refcount_dec_and_test(&nf->nf_ref))],
as nf->nf_ref is already 0, nf->nf_ref is set to REFCOUNT_SATURATED, and the 'nf'
gets no chance of being freed.
nfsd_file_put() can also race with nfsd_file_cond_queue():
* In nfsd_file_put(), nf->nf_ref is 1, so it tries to do nfsd_file_lru_add().
* nfsd_file_lru_add() sets REFERENCED bit and returns true.
* Some userland application runs 'exportfs -f' or something like that, which triggers
__nfsd_file_cache_purge() -> nfsd_file_cond_queue().
* In nfsd_file_cond_queue(), it runs [if (!nfsd_file_unhash(nf))], unhash is done
successfully.
* nfsd_file_cond_queue() runs [if (!nfsd_file_get(nf))], now nf->nf_ref goes to 2.
* nfsd_file_cond_queue() runs [if (nfsd_file_lru_remove(nf))], it succeeds.
* nfsd_file_cond_queue() runs [if (refcount_sub_and_test(decrement, &nf->nf_ref))]
(with "decrement" being 2), so the nf->nf_ref goes to 0, the 'nf' is added to the
dispose list [list_add(&nf->nf_lru, dispose)]
* nfsd_file_put() detects NFSD_FILE_HASHED bit is cleared, so it tries to remove
the 'nf' from the LRU [if (!nfsd_file_lru_remove(nf))], although the 'nf' is not
in the LRU, but it is linked in the 'dispose' list, nfsd_file_lru_remove() simply
treats it as part of the LRU and removes it. This leads to its removal from
the 'dispose' list!
* Now nf->ref is 0, unhashed. nfsd_file_put() continues its execution and set
nf->nf_ref to REFCOUNT_SATURATED.
As shown in the above analysis, using nf_lru for both the LRU list and dispose list
can cause the leaks. This patch adds a new list_head nf_gc in struct nfsd_file, and uses
it for the dispose list. This does not fix the nfsd_file leaking issue completely.
Signed-off-by: Youzhong Yang <youzhong@gmail.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>
[ 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>
[ 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>
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>
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>
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>
[ 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>
[ 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>
[ 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>
[ Upstream commit 8286f8b622 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 63fab04cbd ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit aadc3bbea1 ]
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>
Link: https://nvd.nist.gov/vuln/detail/CVE-2024-49974
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9ed666eba4 ]
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>
[ cel: adjusted to apply to origin/linux-6.6.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d5ff2fb2e7 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dc0d0f885a ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 202f39039a upstream.
According to RFC 8881, all minor versions of NFSv4 support PUTPUBFH.
Replace the XDR decoder for PUTPUBFH with a "noop" since we no
longer want the minorversion check, and PUTPUBFH has no arguments to
decode. (Ideally nfsd4_decode_noop should really be called
nfsd4_decode_void).
PUTPUBFH should now behave just like PUTROOTFH.
Reported-by: Cedric Blancher <cedric.blancher@gmail.com>
Fixes: e1a90ebd8b ("NFSD: Combine decode operations for v4 and v4.1")
Cc: Dan Shelton <dan.f.shelton@gmail.com>
Cc: Roland Mainz <roland.mainz@nrubsig.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 45bb63ed20 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d078cbf5c3 ]
If not enough buffer space available, but idmap_lookup has triggered
lookup_fn which calls cache_get and returns successfully. Then we
missed to call cache_put here which pairs with cache_get.
Fixes: ddd1ea5636 ("nfsd4: use xdr_reserve_space in attribute encoding")
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviwed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a79261763 ]
If we wait_for_construction and find that the file is no longer hashed,
and we're going to retry the open, the old nfsd_file reference is
currently leaked. Put the reference before retrying.
Fixes: c6593366c0 ("nfsd: don't kill nfsd_files because of lease break error")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Youzhong Yang <youzhong@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 81a95c2b1d ]
Given that we do the search and insertion while holding the i_lock, I
don't think it's possible for us to get EEXIST here. Remove this case.
Fixes: c6593366c0 ("nfsd: don't kill nfsd_files because of lease break error")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Youzhong Yang <youzhong@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bf32075256 upstream.
The error paths in nfsd_svc() are needlessly complex and can result in a
final call to svc_put() without nfsd_last_thread() being called. This
results in the listening sockets not being closed properly.
The per-netns setup provided by nfsd_startup_new() and removed by
nfsd_shutdown_net() is needed precisely when there are running threads.
So we don't need nfsd_up_before. We don't need to know if it *was* up.
We only need to know if any threads are left. If none are, then we must
call nfsd_shutdown_net(). But we don't need to do that explicitly as
nfsd_last_thread() does that for us.
So simply call nfsd_last_thread() before the last svc_put() if there are
no running threads. That will always do the right thing.
Also discard:
pr_info("nfsd: last server has exited, flushing export cache\n");
It may not be true if an attempt to start the first server failed, and
it isn't particularly helpful and it simply reports normal behaviour.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reported-by: Li Lingfeng <lilingfeng3@huawei.com>
Suggested-by: Li Lingfeng <lilingfeng3@huawei.com>
Tested-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 16fb9808ab ]
The final bit of stats that is global is the rpc svc_stat. Move this
into the nfsd_net struct and use that everywhere instead of the global
struct. Remove the unused global struct.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit e41ee44cc6 ]
This is the last global stat, take it out of the nfsd_stats struct and
make it a global part of nfsd, report it the same as always.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit 4b14885411 ]
We have a global set of counters that we modify for all of the nfsd
operations, but now that we're exposing these stats across all network
namespaces we need to make the stats also be per-network namespace. We
already have some caching stats that are per-network namespace, so move
these definitions into the same counter and then adjust all the helpers
and users of these stats to provide the appropriate nfsd_net struct so
that the stats are maintained for the per-network namespace objects.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit 93483ac5fe ]
We are running nfsd servers inside of containers with their own network
namespace, and we want to monitor these services using the stats found
in /proc. However these are not exposed in the proc inside of the
container, so we have to bind mount the host /proc into our containers
to get at this information.
Separate out the stat counters init and the proc registration, and move
the proc registration into the pernet operations entry and exit points
so that these stats can be exposed inside of network namespaces.
This is an intermediate step, this just exposes the global counters in
the network namespace. Subsequent patches will move these counters into
the per-network namespace container.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit d98416cc21 ]
We're going to merge the stats all into per network namespace in
subsequent patches, rename these nn counters to be consistent with the
rest of the stats.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit 3f6ef182f1 ]
Now that this isn't used anywhere, remove it.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit f094323867 ]
Since only one service actually reports the rpc stats there's not much
of a reason to have a pointer to it in the svc_program struct. Adjust
the svc_create_pooled function to take the sv_stats as an argument and
pass the struct through there as desired instead of getting it from the
svc_program->pg_stats.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
[ cel: adjusted to apply to v6.6.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a2214ed588 ]
A lot of places are setting a blank svc_stats in ->pg_stats and never
utilizing these stats. Remove all of these extra structs as we're not
reporting these stats anywhere.
Signed-off-by: Josef Bacik <josef@toxicpanda.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>
[ Upstream commit 6939ace1f2 ]
fs/nfsd/export.c: In function 'svc_export_parse':
fs/nfsd/export.c:737:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]
737 | }
On my systems, svc_export_parse() has a stack frame of over 800
bytes, not 1040, but nonetheless, it could do with some reduction.
When a struct svc_export is on the stack, it's a temporary structure
used as an argument, and not visible as an actual exported FS. No
need to reserve space for export_stats in such cases.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310012359.YEw5IrK6-lkp@intel.com/
Cc: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Stable-dep-of: 4b14885411 ("nfsd: make all of the nfsd stats per-network namespace")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5ec39944f8 ]
In function ‘export_stats_init’,
inlined from ‘svc_export_alloc’ at fs/nfsd/export.c:866:6:
fs/nfsd/export.c:337:16: warning: ‘nfsd_percpu_counters_init’ accessing 40 bytes in a region of size 0 [-Wstringop-overflow=]
337 | return nfsd_percpu_counters_init(&stats->counter, EXP_STATS_COUNTERS_NUM);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/nfsd/export.c:337:16: note: referencing argument 1 of type ‘struct percpu_counter[0]’
fs/nfsd/stats.h: In function ‘svc_export_alloc’:
fs/nfsd/stats.h:40:5: note: in a call to function ‘nfsd_percpu_counters_init’
40 | int nfsd_percpu_counters_init(struct percpu_counter counters[], int num);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
Cc: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Stable-dep-of: 93483ac5fe ("nfsd: expose /proc/net/sunrpc/nfsd in net namespaces")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit abc02e5602 upstream.
I noticed LAYOUTGET(LAYOUTIOMODE4_RW) returning NFS4ERR_ACCESS
unexpectedly. The NFS client had created a file with mode 0444, and
the server had returned a write delegation on the OPEN(CREATE). The
client was requesting a RW layout using the write delegation stateid
so that it could flush file modifications.
Creating a read-only file does not seem to be problematic for
NFSv4.1 without pNFS, so I began looking at NFSD's implementation of
LAYOUTGET.
The failure was because fh_verify() was doing a permission check as
part of verifying the FH presented during the LAYOUTGET. It uses the
loga_iomode value to specify the @accmode argument to fh_verify().
fh_verify(MAY_WRITE) on a file whose mode is 0444 fails with -EACCES.
To permit LAYOUT* operations in this case, add OWNER_OVERRIDE when
checking the access permission of the incoming file handle for
LAYOUTGET and LAYOUTCOMMIT.
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # v6.6+
Message-Id: 4E9C0D74-A06D-4DC3-A48A-73034DC40395@oracle.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e221c45da3 upstream.
The 'NFS error' NFSERR_OPNOTSUPP is not described by any of the official
NFS related RFCs, but appears to have snuck into some older .x files for
NFSv2.
Either way, it is not in RFC1094, RFC1813 or any of the NFSv4 RFCs, so
should not be returned by the knfsd server, and particularly not by the
"LOOKUP" operation.
Instead, let's return NFSERR_STALE, which is more appropriate if the
filesystem encodes the filehandle as FILEID_INVALID.
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 10396f4df8 ]
Currently the CB_RECALL_ANY job takes a cl_rpc_users reference to the
client. While a callback job is technically an RPC that counter is
really more for client-driven RPCs, and this has the effect of
preventing the client from being unhashed until the callback completes.
If nfsd decides to send a CB_RECALL_ANY just as the client reboots, we
can end up in a situation where the callback can't complete on the (now
dead) callback channel, but the new client can't connect because the old
client can't be unhashed. This usually manifests as a NFS4ERR_DELAY
return on the CREATE_SESSION operation.
The job is only holding a reference to the client so it can clear a flag
after the RPC completes. Fix this by having CB_RECALL_ANY instead hold a
reference to the cl_nfsdfs.cl_ref. Typically we only take that sort of
reference when dealing with the nfsdfs info files, but it should work
appropriately here to ensure that the nfs4_client doesn't disappear.
Fixes: 44df6f439a ("NFSD: add delegation reaper to react to low memory condition")
Reported-by: Vladimir Benes <vbenes@redhat.com>
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>
[ Upstream commit 9388a2aa45 ]
I'm working on restructuring the __string* macros so that it doesn't need
to recalculate the string twice. That is, it will save it off when
processing __string() and the __assign_str() will not need to do the work
again as it currently does.
Currently __string_len(item, src, len) doesn't actually use "src", but my
changes will require src to be correct as that is where the __assign_str()
will get its value from.
The event class nfsd_clid_class has:
__string_len(name, name, clp->cl_name.len)
But the second "name" does not exist and causes my changes to fail to
build. That second parameter should be: clp->cl_name.data.
Link: https://lore.kernel.org/linux-trace-kernel/20240222122828.3d8d213c@gandalf.local.home
Cc: Neil Brown <neilb@suse.de>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: stable@vger.kernel.org
Fixes: d27b74a867 ("NFSD: Use new __string_len C macros for nfsd_clid_class")
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5ea9a7c5fe upstream.
A recent change to check_for_locks() changed it to take ->flc_lock while
holding ->fi_lock. This creates a lock inversion (reported by lockdep)
because there is a case where ->fi_lock is taken while holding
->flc_lock.
->flc_lock is held across ->fl_lmops callbacks, and
nfsd_break_deleg_cb() is one of those and does take ->fi_lock. However
it doesn't need to.
Prior to v4.17-rc1~110^2~22 ("nfsd: create a separate lease for each
delegation") nfsd_break_deleg_cb() would walk the ->fi_delegations list
and so needed the lock. Since then it doesn't walk the list and doesn't
need the lock.
Two actions are performed under the lock. One is to call
nfsd_break_one_deleg which calls nfsd4_run_cb(). These doesn't act on
the nfs4_file at all, so don't need the lock.
The other is to set ->fi_had_conflict which is in the nfs4_file.
This field is only ever set here (except when initialised to false)
so there is no possible problem will multiple threads racing when
setting it.
The field is tested twice in nfs4_set_delegation(). The first test does
not hold a lock and is documented as an opportunistic optimisation, so
it doesn't impose any need to hold ->fi_lock while setting
->fi_had_conflict.
The second test in nfs4_set_delegation() *is* make under ->fi_lock, so
removing the locking when ->fi_had_conflict is set could make a change.
The change could only be interesting if ->fi_had_conflict tested as
false even though nfsd_break_one_deleg() ran before ->fi_lock was
unlocked. i.e. while hash_delegation_locked() was running.
As hash_delegation_lock() doesn't interact in any way with nfs4_run_cb()
there can be no importance to this interaction.
So this patch removes the locking from nfsd_break_one_deleg() and moves
the final test on ->fi_had_conflict out of the locked region to make it
clear that locking isn't important to the test. It is still tested
*after* vfs_setlease() has succeeded. This might be significant and as
vfs_setlease() takes ->flc_lock, and nfsd_break_one_deleg() is called
under ->flc_lock this "after" is a true ordering provided by a spinlock.
Fixes: edcf972515 ("nfsd: fix RELEASE_LOCKOWNER")
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit edcf972515 upstream.
The test on so_count in nfsd4_release_lockowner() is nonsense and
harmful. Revert to using check_for_locks(), changing that to not sleep.
First: harmful.
As is documented in the kdoc comment for nfsd4_release_lockowner(), the
test on so_count can transiently return a false positive resulting in a
return of NFS4ERR_LOCKS_HELD when in fact no locks are held. This is
clearly a protocol violation and with the Linux NFS client it can cause
incorrect behaviour.
If RELEASE_LOCKOWNER is sent while some other thread is still
processing a LOCK request which failed because, at the time that request
was received, the given owner held a conflicting lock, then the nfsd
thread processing that LOCK request can hold a reference (conflock) to
the lock owner that causes nfsd4_release_lockowner() to return an
incorrect error.
The Linux NFS client ignores that NFS4ERR_LOCKS_HELD error because it
never sends NFS4_RELEASE_LOCKOWNER without first releasing any locks, so
it knows that the error is impossible. It assumes the lock owner was in
fact released so it feels free to use the same lock owner identifier in
some later locking request.
When it does reuse a lock owner identifier for which a previous RELEASE
failed, it will naturally use a lock_seqid of zero. However the server,
which didn't release the lock owner, will expect a larger lock_seqid and
so will respond with NFS4ERR_BAD_SEQID.
So clearly it is harmful to allow a false positive, which testing
so_count allows.
The test is nonsense because ... well... it doesn't mean anything.
so_count is the sum of three different counts.
1/ the set of states listed on so_stateids
2/ the set of active vfs locks owned by any of those states
3/ various transient counts such as for conflicting locks.
When it is tested against '2' it is clear that one of these is the
transient reference obtained by find_lockowner_str_locked(). It is not
clear what the other one is expected to be.
In practice, the count is often 2 because there is precisely one state
on so_stateids. If there were more, this would fail.
In my testing I see two circumstances when RELEASE_LOCKOWNER is called.
In one case, CLOSE is called before RELEASE_LOCKOWNER. That results in
all the lock states being removed, and so the lockowner being discarded
(it is removed when there are no more references which usually happens
when the lock state is discarded). When nfsd4_release_lockowner() finds
that the lock owner doesn't exist, it returns success.
The other case shows an so_count of '2' and precisely one state listed
in so_stateid. It appears that the Linux client uses a separate lock
owner for each file resulting in one lock state per lock owner, so this
test on '2' is safe. For another client it might not be safe.
So this patch changes check_for_locks() to use the (newish)
find_any_file_locked() so that it doesn't take a reference on the
nfs4_file and so never calls nfsd_file_put(), and so never sleeps. With
this check is it safe to restore the use of check_for_locks() rather
than testing so_count against the mysterious '2'.
Fixes: ce3c4ad7f4 ("NFSD: Fix possible sleep during nfsd4_release_lockowner()")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org # v6.2+
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
