linux-stable.git/fs/nfsd, branch linux-4.9.y

nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failure

2023-01-07T11:07:29+00:00

[ Upstream commit 3bc8edc98bd43540dbe648e4ef91f443d6d20a24 ]

On error situation `clp->cl_cb_conn.cb_xprt` should not be given
a reference to the xprt otherwise both client cleanup and the
error handling path of the caller call to put it. Better to
delay handing over the reference to a later branch.

[   72.530665] refcount_t: underflow; use-after-free.
[   72.531933] WARNING: CPU: 0 PID: 173 at lib/refcount.c:28 refcount_warn_saturate+0xcf/0x120
[   72.533075] Modules linked in: nfsd(OE) nfsv4(OE) nfsv3(OE) nfs(OE) lockd(OE) compat_nfs_ssc(OE) nfs_acl(OE) rpcsec_gss_krb5(OE) auth_rpcgss(OE) rpcrdma(OE) dns_resolver fscache netfs grace rdma_cm iw_cm ib_cm sunrpc(OE) mlx5_ib mlx5_core mlxfw pci_hyperv_intf ib_uverbs ib_core xt_MASQUERADE nf_conntrack_netlink nft_counter xt_addrtype nft_compat br_netfilter bridge stp llc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set overlay nf_tables nfnetlink crct10dif_pclmul crc32_pclmul ghash_clmulni_intel xfs serio_raw virtio_net virtio_blk net_failover failover fuse [last unloaded: sunrpc]
[   72.540389] CPU: 0 PID: 173 Comm: kworker/u16:5 Tainted: G           OE     5.15.82-dan #1
[   72.541511] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-3.module+el8.7.0+1084+97b81f61 04/01/2014
[   72.542717] Workqueue: nfsd4_callbacks nfsd4_run_cb_work [nfsd]
[   72.543575] RIP: 0010:refcount_warn_saturate+0xcf/0x120
[   72.544299] Code: 55 00 0f 0b 5d e9 01 50 98 00 80 3d 75 9e 39 08 00 0f 85 74 ff ff ff 48 c7 c7 e8 d1 60 8e c6 05 61 9e 39 08 01 e8 f6 51 55 00 <0f> 0b 5d e9 d9 4f 98 00 80 3d 4b 9e 39 08 00 0f 85 4c ff ff ff 48
[   72.546666] RSP: 0018:ffffb3f841157cf0 EFLAGS: 00010286
[   72.547393] RAX: 0000000000000026 RBX: ffff89ac6231d478 RCX: 0000000000000000
[   72.548324] RDX: ffff89adb7c2c2c0 RSI: ffff89adb7c205c0 RDI: ffff89adb7c205c0
[   72.549271] RBP: ffffb3f841157cf0 R08: 0000000000000000 R09: c0000000ffefffff
[   72.550209] R10: 0000000000000001 R11: ffffb3f841157ad0 R12: ffff89ac6231d180
[   72.551142] R13: ffff89ac6231d478 R14: ffff89ac40c06180 R15: ffff89ac6231d4b0
[   72.552089] FS:  0000000000000000(0000) GS:ffff89adb7c00000(0000) knlGS:0000000000000000
[   72.553175] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   72.553934] CR2: 0000563a310506a8 CR3: 0000000109a66000 CR4: 0000000000350ef0
[   72.554874] Call Trace:
[   72.555278]  
[   72.555614]  svc_xprt_put+0xaf/0xe0 [sunrpc]
[   72.556276]  nfsd4_process_cb_update.isra.11+0xb7/0x410 [nfsd]
[   72.557087]  ? update_load_avg+0x82/0x610
[   72.557652]  ? cpuacct_charge+0x60/0x70
[   72.558212]  ? dequeue_entity+0xdb/0x3e0
[   72.558765]  ? queued_spin_unlock+0x9/0x20
[   72.559358]  nfsd4_run_cb_work+0xfc/0x270 [nfsd]
[   72.560031]  process_one_work+0x1df/0x390
[   72.560600]  worker_thread+0x37/0x3b0
[   72.561644]  ? process_one_work+0x390/0x390
[   72.562247]  kthread+0x12f/0x150
[   72.562710]  ? set_kthread_struct+0x50/0x50
[   72.563309]  ret_from_fork+0x22/0x30
[   72.563818]  
[   72.564189] ---[ end trace 031117b1c72ec616 ]---
[   72.566019] list_add corruption. next->prev should be prev (ffff89ac4977e538), but was ffff89ac4763e018. (next=ffff89ac4763e018).
[   72.567647] ------------[ cut here ]------------

Fixes: a4abc6b12eb1 ("nfsd: Fix svc_xprt refcnt leak when setup callback client failed")
Cc: Xiyu Yang 
Cc: J. Bruce Fields 
Signed-off-by: Dan Aloni 
Reviewed-by: Jeff Layton 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

NFSD: Fix possible sleep during nfsd4_release_lockowner()

2022-06-06T06:19:46+00:00

commit ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b upstream.

nfsd4_release_lockowner() holds clp->cl_lock when it calls
check_for_locks(). However, check_for_locks() calls nfsd_file_get()
/ nfsd_file_put() to access the backing inode's flc_posix list, and
nfsd_file_put() can sleep if the inode was recently removed.

Let's instead rely on the stateowner's reference count to gate
whether the release is permitted. This should be a reliable
indication of locks-in-use since file lock operations and
->lm_get_owner take appropriate references, which are released
appropriately when file locks are removed.

Reported-by: Dai Ngo 
Signed-off-by: Chuck Lever 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

NFSD: prevent underflow in nfssvc_decode_writeargs()

2022-04-20T07:06:28+00:00

commit 184416d4b98509fb4c3d8fc3d6dc1437896cc159 upstream.

Smatch complains:

	fs/nfsd/nfsxdr.c:341 nfssvc_decode_writeargs()
	warn: no lower bound on 'args->len'

Change the type to unsigned to prevent this issue.

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter 
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

NFSD: Clamp WRITE offsets

2022-02-16T11:43:52+00:00

commit 6260d9a56ab352b54891ec66ab0eced57d55abc6 upstream.

Ensure that a client cannot specify a WRITE range that falls in a
byte range outside what the kernel's internal types (such as loff_t,
which is signed) can represent. The kiocb iterators, invoked in
nfsd_vfs_write(), should properly limit write operations to within
the underlying file system's s_maxbytes.

Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

nfsd: nfsd4_setclientid_confirm mistakenly expires confirmed client.

2022-02-08T17:15:29+00:00

commit ab451ea952fe9d7afefae55ddb28943a148247fe upstream.

From RFC 7530 Section 16.34.5:

o  The server has not recorded an unconfirmed { v, x, c, *, * } and
   has recorded a confirmed { v, x, c, *, s }.  If the principals of
   the record and of SETCLIENTID_CONFIRM do not match, the server
   returns NFS4ERR_CLID_INUSE without removing any relevant leased
   client state, and without changing recorded callback and
   callback_ident values for client { x }.

The current code intends to do what the spec describes above but
it forgot to set 'old' to NULL resulting to the confirmed client
to be expired.

Fixes: 2b63482185e6 ("nfsd: fix clid_inuse on mount with security change")
Signed-off-by: Dai Ngo 
Signed-off-by: Chuck Lever 
Reviewed-by: Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

nfsd: fix use-after-free due to delegation race

2021-12-22T08:05:14+00:00

commit 548ec0805c399c65ed66c6641be467f717833ab5 upstream.

A delegation break could arrive as soon as we've called vfs_setlease.  A
delegation break runs a callback which immediately (in
nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru.  If we
then exit nfs4_set_delegation without hashing the delegation, it will be
freed as soon as the callback is done with it, without ever being
removed from del_recall_lru.

Symptoms show up later as use-after-free or list corruption warnings,
usually in the laundromat thread.

I suspect aba2072f4523 "nfsd: grant read delegations to clients holding
writes" made this bug easier to hit, but I looked as far back as v3.0
and it looks to me it already had the same problem.  So I'm not sure
where the bug was introduced; it may have been there from the beginning.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields 
[Salvatore Bonaccorso: Backport for context changes to versions which do
not have 20b7d86f29d3 ("nfsd: use boottime for lease expiry calculation")]
Signed-off-by: Salvatore Bonaccorso 
Signed-off-by: Greg Kroah-Hartman

NFSD: Keep existing listeners on portlist error

2021-10-27T07:33:59+00:00

[ Upstream commit c20106944eb679fa3ab7e686fe5f6ba30fbc51e5 ]

If nfsd has existing listening sockets without any processes, then an error
returned from svc_create_xprt() for an additional transport will remove
those existing listeners.  We're seeing this in practice when userspace
attempts to create rpcrdma transports without having the rpcrdma modules
present before creating nfsd kernel processes.  Fix this by checking for
existing sockets before calling nfsd_destroy().

Signed-off-by: Benjamin Coddington 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin

nfsd4: Handle the NFSv4 READDIR 'dircount' hint being zero

2021-10-17T08:05:38+00:00

commit f2e717d655040d632c9015f19aa4275f8b16e7f2 upstream.

RFC3530 notes that the 'dircount' field may be zero, in which case the
recommendation is to ignore it, and only enforce the 'maxcount' field.
In RFC5661, this recommendation to ignore a zero valued field becomes a
requirement.

Fixes: aee377644146 ("nfsd4: fix rd_dircount enforcement")
Cc: 
Signed-off-by: Trond Myklebust 
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

nfsd4: readdirplus shouldn't return parent of export

2021-01-23T14:38:18+00:00

commit 51b2ee7d006a736a9126e8111d1f24e4fd0afaa6 upstream.

If you export a subdirectory of a filesystem, a READDIRPLUS on the root
of that export will return the filehandle of the parent with the ".."
entry.

The filehandle is optional, so let's just not return the filehandle for
".." if we're at the root of an export.

Note that once the client learns one filehandle outside of the export,
they can trivially access the rest of the export using further lookups.

However, it is also not very difficult to guess filehandles outside of
the export.  So exporting a subdirectory of a filesystem should
considered equivalent to providing access to the entire filesystem.  To
avoid confusion, we recommend only exporting entire filesystems.

Reported-by: Youjipeng 
Signed-off-by: J. Bruce Fields 
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever 
Signed-off-by: Greg Kroah-Hartman

nfsd: Fix message level for normal termination

2020-12-29T12:44:59+00:00

[ Upstream commit 4420440c57892779f265108f46f83832a88ca795 ]

The warning message from nfsd terminating normally
can confuse system adminstrators or monitoring software.

Though it's not exactly fair to pin-point a commit where it
originated, the current form in the current place started
to appear in:

Fixes: e096bbc6488d ("knfsd: remove special handling for SIGHUP")
Signed-off-by: kazuo ito 
Signed-off-by: Chuck Lever 
Signed-off-by: Sasha Levin