Commit Graph

1250779 Commits

Author SHA1 Message Date
Kuniyuki Iwashima
24457f1be2 nfs: Handle error of rpc_proc_register() in nfs_net_init().
syzkaller reported a warning [0] triggered while destroying immature
netns.

rpc_proc_register() was called in init_nfs_fs(), but its error
has been ignored since at least the initial commit 1da177e4c3
("Linux-2.6.12-rc2").

Recently, commit d47151b79e ("nfs: expose /proc/net/sunrpc/nfs
in net namespaces") converted the procfs to per-netns and made
the problem more visible.

Even when rpc_proc_register() fails, nfs_net_init() could succeed,
and thus nfs_net_exit() will be called while destroying the netns.

Then, remove_proc_entry() will be called for non-existing proc
directory and trigger the warning below.

Let's handle the error of rpc_proc_register() properly in nfs_net_init().

[0]:
name 'nfs'
WARNING: CPU: 1 PID: 1710 at fs/proc/generic.c:711 remove_proc_entry+0x1bb/0x2d0 fs/proc/generic.c:711
Modules linked in:
CPU: 1 PID: 1710 Comm: syz-executor.2 Not tainted 6.8.0-12822-gcd51db110a7e #12
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:remove_proc_entry+0x1bb/0x2d0 fs/proc/generic.c:711
Code: 41 5d 41 5e c3 e8 85 09 b5 ff 48 c7 c7 88 58 64 86 e8 09 0e 71 02 e8 74 09 b5 ff 4c 89 e6 48 c7 c7 de 1b 80 84 e8 c5 ad 97 ff <0f> 0b eb b1 e8 5c 09 b5 ff 48 c7 c7 88 58 64 86 e8 e0 0d 71 02 eb
RSP: 0018:ffffc9000c6d7ce0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8880422b8b00 RCX: ffffffff8110503c
RDX: ffff888030652f00 RSI: ffffffff81105045 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff81bb62cb R12: ffffffff84807ffc
R13: ffff88804ad6fcc0 R14: ffffffff84807ffc R15: ffffffff85741ff8
FS:  00007f30cfba8640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff51afe8000 CR3: 000000005a60a005 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 rpc_proc_unregister+0x64/0x70 net/sunrpc/stats.c:310
 nfs_net_exit+0x1c/0x30 fs/nfs/inode.c:2438
 ops_exit_list+0x62/0xb0 net/core/net_namespace.c:170
 setup_net+0x46c/0x660 net/core/net_namespace.c:372
 copy_net_ns+0x244/0x590 net/core/net_namespace.c:505
 create_new_namespaces+0x2ed/0x770 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xae/0x160 kernel/nsproxy.c:228
 ksys_unshare+0x342/0x760 kernel/fork.c:3322
 __do_sys_unshare kernel/fork.c:3393 [inline]
 __se_sys_unshare kernel/fork.c:3391 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3391
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x46/0x4e
RIP: 0033:0x7f30d0febe5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007f30cfba7cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007f30d0febe5d
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c020600
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f30d104c530 R15: 0000000000000000
 </TASK>

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-04-04 18:27:13 -04:00
Olga Kornievskaia
8e088a20db SUNRPC: add a missing rpc_stat for TCP TLS
Commit 1548036ef1 ("nfs: make the rpc_stat per net namespace") added
functionality to specify rpc_stats function but missed adding it to the
TCP TLS functionality. As the result, mounting with xprtsec=tls lead to
the following kernel oops.

[  128.984192] Unable to handle kernel NULL pointer dereference at
virtual address 000000000000001c
[  128.985058] Mem abort info:
[  128.985372]   ESR = 0x0000000096000004
[  128.985709]   EC = 0x25: DABT (current EL), IL = 32 bits
[  128.986176]   SET = 0, FnV = 0
[  128.986521]   EA = 0, S1PTW = 0
[  128.986804]   FSC = 0x04: level 0 translation fault
[  128.987229] Data abort info:
[  128.987597]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  128.988169]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  128.988811]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  128.989302] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000106c84000
[  128.990048] [000000000000001c] pgd=0000000000000000, p4d=0000000000000000
[  128.990736] Internal error: Oops: 0000000096000004 [#1] SMP
[  128.991168] Modules linked in: nfs_layout_nfsv41_files
rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace netfs
uinput dm_mod nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib
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 rfkill
ip_set nf_tables nfnetlink qrtr vsock_loopback
vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock
sunrpc vfat fat uvcvideo videobuf2_vmalloc videobuf2_memops uvc
videobuf2_v4l2 videodev videobuf2_common mc vmw_vmci xfs libcrc32c
e1000e crct10dif_ce ghash_ce sha2_ce vmwgfx nvme sha256_arm64
nvme_core sr_mod cdrom sha1_ce drm_ttm_helper ttm drm_kms_helper drm
sg fuse
[  128.996466] CPU: 0 PID: 179 Comm: kworker/u4:26 Kdump: loaded Not
tainted 6.8.0-rc6+ #12
[  128.997226] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS
VMW201.00V.21805430.BA64.2305221830 05/22/2023
[  128.998084] Workqueue: xprtiod xs_tcp_tls_setup_socket [sunrpc]
[  128.998701] pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[  128.999384] pc : call_start+0x74/0x138 [sunrpc]
[  128.999809] lr : __rpc_execute+0xb8/0x3e0 [sunrpc]
[  129.000244] sp : ffff8000832b3a00
[  129.000508] x29: ffff8000832b3a00 x28: ffff800081ac79c0 x27: ffff800081ac7000
[  129.001111] x26: 0000000004248060 x25: 0000000000000000 x24: ffff800081596008
[  129.001757] x23: ffff80007b087240 x22: ffff00009a509d30 x21: 0000000000000000
[  129.002345] x20: ffff000090075600 x19: ffff00009a509d00 x18: ffffffffffffffff
[  129.002912] x17: 733d4d4554535953 x16: 42555300312d746e x15: ffff8000832b3a88
[  129.003464] x14: ffffffffffffffff x13: ffff8000832b3a7d x12: 0000000000000008
[  129.004021] x11: 0101010101010101 x10: ffff8000150cb560 x9 : ffff80007b087c00
[  129.004577] x8 : ffff00009a509de0 x7 : 0000000000000000 x6 : 00000000be8c4ee3
[  129.005026] x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff000094d56680
[  129.005425] x2 : ffff80007b0637f8 x1 : ffff000090075600 x0 : ffff00009a509d00
[  129.005824] Call trace:
[  129.005967]  call_start+0x74/0x138 [sunrpc]
[  129.006233]  __rpc_execute+0xb8/0x3e0 [sunrpc]
[  129.006506]  rpc_execute+0x160/0x1d8 [sunrpc]
[  129.006778]  rpc_run_task+0x148/0x1f8 [sunrpc]
[  129.007204]  tls_probe+0x80/0xd0 [sunrpc]
[  129.007460]  rpc_ping+0x28/0x80 [sunrpc]
[  129.007715]  rpc_create_xprt+0x134/0x1a0 [sunrpc]
[  129.007999]  rpc_create+0x128/0x2a0 [sunrpc]
[  129.008264]  xs_tcp_tls_setup_socket+0xdc/0x508 [sunrpc]
[  129.008583]  process_one_work+0x174/0x3c8
[  129.008813]  worker_thread+0x2c8/0x3e0
[  129.009033]  kthread+0x100/0x110
[  129.009225]  ret_from_fork+0x10/0x20
[  129.009432] Code: f0ffffc2 911fe042 aa1403e1 aa1303e0 (b9401c83)

Fixes: 1548036ef1 ("nfs: make the rpc_stat per net namespace")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-04-04 09:30:08 -04:00
Josef Bacik
719fcafe07 nfs: fix panic when nfs4_ff_layout_prepare_ds() fails
We've been seeing the following panic in production

BUG: kernel NULL pointer dereference, address: 0000000000000065
PGD 2f485f067 P4D 2f485f067 PUD 2cc5d8067 PMD 0
RIP: 0010:ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
Call Trace:
 <TASK>
 ? __die+0x78/0xc0
 ? page_fault_oops+0x286/0x380
 ? __rpc_execute+0x2c3/0x470 [sunrpc]
 ? rpc_new_task+0x42/0x1c0 [sunrpc]
 ? exc_page_fault+0x5d/0x110
 ? asm_exc_page_fault+0x22/0x30
 ? ff_layout_free_layoutreturn+0x110/0x110 [nfs_layout_flexfiles]
 ? ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
 ? ff_layout_cancel_io+0x6f/0x90 [nfs_layout_flexfiles]
 pnfs_mark_matching_lsegs_return+0x1b0/0x360 [nfsv4]
 pnfs_error_mark_layout_for_return+0x9e/0x110 [nfsv4]
 ? ff_layout_send_layouterror+0x50/0x160 [nfs_layout_flexfiles]
 nfs4_ff_layout_prepare_ds+0x11f/0x290 [nfs_layout_flexfiles]
 ff_layout_pg_init_write+0xf0/0x1f0 [nfs_layout_flexfiles]
 __nfs_pageio_add_request+0x154/0x6c0 [nfs]
 nfs_pageio_add_request+0x26b/0x380 [nfs]
 nfs_do_writepage+0x111/0x1e0 [nfs]
 nfs_writepages_callback+0xf/0x30 [nfs]
 write_cache_pages+0x17f/0x380
 ? nfs_pageio_init_write+0x50/0x50 [nfs]
 ? nfs_writepages+0x6d/0x210 [nfs]
 ? nfs_writepages+0x6d/0x210 [nfs]
 nfs_writepages+0x125/0x210 [nfs]
 do_writepages+0x67/0x220
 ? generic_perform_write+0x14b/0x210
 filemap_fdatawrite_wbc+0x5b/0x80
 file_write_and_wait_range+0x6d/0xc0
 nfs_file_fsync+0x81/0x170 [nfs]
 ? nfs_file_mmap+0x60/0x60 [nfs]
 __x64_sys_fsync+0x53/0x90
 do_syscall_64+0x3d/0x90
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Inspecting the core with drgn I was able to pull this

  >>> prog.crashed_thread().stack_trace()[0]
  #0 at 0xffffffffa079657a (ff_layout_cancel_io+0x3a/0x84) in ff_layout_cancel_io at fs/nfs/flexfilelayout/flexfilelayout.c:2021:27
  >>> prog.crashed_thread().stack_trace()[0]['idx']
  (u32)1
  >>> prog.crashed_thread().stack_trace()[0]['flseg'].mirror_array[1].mirror_ds
  (struct nfs4_ff_layout_ds *)0xffffffffffffffed

This is clear from the stack trace, we call nfs4_ff_layout_prepare_ds()
which could error out initializing the mirror_ds, and then we go to
clean it all up and our check is only for if (!mirror->mirror_ds).  This
is inconsistent with the rest of the users of mirror_ds, which have

  if (IS_ERR_OR_NULL(mirror_ds))

to keep from tripping over this exact scenario.  Fix this up in
ff_layout_cancel_io() to make sure we don't panic when we get an error.
I also spot checked all the other instances of checking mirror_ds and we
appear to be doing the correct checks everywhere, only unconditionally
dereferencing mirror_ds when we know it would be valid.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Fixes: b739a5bd9d ("NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-16 12:41:45 -04:00
Chen Hanxiao
e9efd5fe75 NFS: trace the uniquifier of fscache
Trace the mount option fsc=xxx.

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Benjamin Coddington
11974eec83 NFS: Read unlock folio on nfs_page_create_from_folio() error
The netfs conversion lost a folio_unlock() for the case where
nfs_page_create_from_folio() returns an error (usually -ENOMEM).  Restore
it.

Reported-by: David Jeffery <djeffery@redhat.com>
Cc: <stable@vger.kernel.org> # 6.4+
Fixes: 000dbe0bec ("NFS: Convert buffered read paths to use netfs when fscache is enabled")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Acked-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Trond Myklebust
cdbd321ac1 NFS: remove unused variable nfs_rpcstat
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Josef Bacik
17f46b803d nfs: fix UAF in direct writes
In production we have been hitting the following warning consistently

------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0
Workqueue: nfsiod nfs_direct_write_schedule_work [nfs]
RIP: 0010:refcount_warn_saturate+0x9c/0xe0
PKRU: 55555554
Call Trace:
 <TASK>
 ? __warn+0x9f/0x130
 ? refcount_warn_saturate+0x9c/0xe0
 ? report_bug+0xcc/0x150
 ? handle_bug+0x3d/0x70
 ? exc_invalid_op+0x16/0x40
 ? asm_exc_invalid_op+0x16/0x20
 ? refcount_warn_saturate+0x9c/0xe0
 nfs_direct_write_schedule_work+0x237/0x250 [nfs]
 process_one_work+0x12f/0x4a0
 worker_thread+0x14e/0x3b0
 ? ZSTD_getCParams_internal+0x220/0x220
 kthread+0xdc/0x120
 ? __btf_name_valid+0xa0/0xa0
 ret_from_fork+0x1f/0x30

This is because we're completing the nfs_direct_request twice in a row.

The source of this is when we have our commit requests to submit, we
process them and send them off, and then in the completion path for the
commit requests we have

if (nfs_commit_end(cinfo.mds))
	nfs_direct_write_complete(dreq);

However since we're submitting asynchronous requests we sometimes have
one that completes before we submit the next one, so we end up calling
complete on the nfs_direct_request twice.

The only other place we use nfs_generic_commit_list() is in
__nfs_commit_inode, which wraps this call in a

nfs_commit_begin();
nfs_commit_end();

Which is a common pattern for this style of completion handling, one
that is also repeated in the direct code with get_dreq()/put_dreq()
calls around where we process events as well as in the completion paths.

Fix this by using the same pattern for the commit requests.

Before with my 200 node rocksdb stress running this warning would pop
every 10ish minutes.  With my patch the stress test has been running for
several hours without popping.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Josef Bacik
094501358e nfs: properly protect nfs_direct_req fields
We protect accesses to the nfs_direct_req fields with the dreq->lock
ever where except nfs_direct_commit_complete.  This isn't a huge deal,
but it does lead to confusion, and we could potentially end up setting
NFS_ODIRECT_RESCHED_WRITES in one thread where we've had an error in
another.  Clean this up to properly protect ->error and ->flags in the
commit completion path.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Trond Myklebust
b326df4a8e NFS: enable nconnect for RDMA
It appears that in certain cases, RDMA capable transports can benefit
from the ability to establish multiple connections to increase their
throughput. This patch therefore enables the use of the "nconnect" mount
option for those use cases.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Trond Myklebust
0460253913 NFSv4: nfs4_do_open() is incorrectly triggering state recovery
We're seeing spurious calls to nfs4_schedule_stateid_recovery() from
nfs4_do_open() in situations where there is no trigger coming from the
server.
In theory the code path being triggered is supposed to notice that state
recovery happened while we were processing the open call result from the
server, before the open stateid is published. However in the years since
that code was added, we've also added the 'session draining' mechanism,
which ensures that the state recovery will wait until all the session
slots have been returned. In nfs4_do_open() the session slot is only
returned on exit of the function, so we don't need the legacy mechanism.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
NeilBrown
2fdbc20036 NFS: avoid infinite loop in pnfs_update_layout.
If pnfsd_update_layout() is called on a file for which recovery has
failed it will enter a tight infinite loop.

NFS_LAYOUT_INVALID_STID will be set, nfs4_select_rw_stateid() will
return -EIO, and nfs4_schedule_stateid_recovery() will do nothing, so
nfs4_client_recover_expired_lease() will not wait.  So the code will
loop indefinitely.

Break the loop by testing the validity of the open stateid at the top of
the loop.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
NeilBrown
0b81371d3c NFS: remove sync_mode test from nfs_writepage_locked()
nfs_writepage_locked() is only called from nfs_wb_folio() (since Commit
12fc0a9631 ("nfs: Remove writepage")) so ->sync_mode is always
WB_SYNC_ALL.

This means the test for WB_SYNC_NONE is dead code and can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Olga Kornievskaia
a35518cae4 NFSv4.1/pnfs: fix NFS with TLS in pnfs
Currently, even though xprtsec=tls is specified and used for operations
to MDS, any operations that go to DS travel over unencrypted connection.
Or additionally, if more than 1 DS can serve the data, then trunked
connections are also done unencrypted.

IN GETDEVINCEINFO, we get an entry for the DS which carries a protocol
type (which is TCP), then nfs4_set_ds_client() gets called with TCP
instead of TCP with TLS.

Currently, each trunked connection is created and uses clp->cl_hostname
value which if TLS is used would get passed up in the handshake upcall,
but instead we need to pass in the appropriate trunked address value.

Fixes: c8407f2e56 ("NFS: Add an "xprtsec=" NFS mount option")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Christophe JAILLET
698ad1a538 NFS: Fix an off by one in root_nfs_cat()
The intent is to check if 'dest' is truncated or not. So, >= should be
used instead of >, because strlcat() returns the length of 'dest' and 'src'
excluding the trailing NULL.

Fixes: 56463e50d1 ("NFS: Use super.c for NFSROOT mount option parsing")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Josef Bacik
1548036ef1 nfs: make the rpc_stat per net namespace
Now that we're exposing the rpc stats on a per-network namespace basis,
move this struct into struct nfs_net and use that to make sure only the
per-network namespace stats are exposed.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:51 -05:00
Josef Bacik
d47151b79e nfs: expose /proc/net/sunrpc/nfs in net namespaces
We're using nfs mounts inside of containers in production and noticed
that the nfs stats are not exposed in /proc.  This is a problem for us
as we use these stats for monitoring, and have to do this awkward bind
mount from the main host into the container in order to get to these
states.

Add the rpc_proc_register call to the pernet operations entry and exit
points so these stats can be exposed inside of network namespaces.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:50 -05:00
Josef Bacik
2057a48d0d sunrpc: add a struct rpc_stats arg to rpc_create_args
We want to be able to have our rpc stats handled in a per network
namespace manner, so add an option to rpc_create_args to specify a
different rpc_stats struct instead of using the one on the rpc_program.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:50 -05:00
Jeff Layton
edc99a2dd3 nfs: remove unused NFS_CALL macro
Nothing uses this, and thank goodness, as the syntax looks horrid.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:50 -05:00
Olga Kornievskaia
7e5ae43b2d NFSv4.1: add tracepoint to trunked nfs4_exchange_id calls
Add a tracepoint to track when the client sends EXCHANGE_ID to test
a new transport for session trunking.

nfs4_detect_session_trunking() tests for trunking and returns
EINVAL if trunking can't be done, add EINVAL mapping to
show_nfs4_status() in tracepoints.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:50 -05:00
Dave Wysochanski
fd5860ab63 NFS: Fix nfs_netfs_issue_read() xarray locking for writeback interrupt
The loop inside nfs_netfs_issue_read() currently does not disable
interrupts while iterating through pages in the xarray to submit
for NFS read.  This is not safe though since after taking xa_lock,
another page in the mapping could be processed for writeback inside
an interrupt, and deadlock can occur.  The fix is simple and clean
if we use xa_for_each_range(), which handles the iteration with RCU
while reducing code complexity.

The problem is easily reproduced with the following test:
 mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs
 dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1
 echo 3 > /proc/sys/vm/drop_caches
 dd if=/mnt/nfs/file1.bin of=/dev/null
 umount /mnt/nfs

On the console with a lockdep-enabled kernel a message similar to
the following will be seen:

 ================================
 WARNING: inconsistent lock state
 6.7.0-lockdbg+ #10 Not tainted
 --------------------------------
 inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
 test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes:
 ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at:
nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
 {IN-SOFTIRQ-W} state was registered at:
   lock_acquire+0x144/0x380
   _raw_spin_lock_irqsave+0x4e/0xa0
   __folio_end_writeback+0x17e/0x5c0
   folio_end_writeback+0x93/0x1b0
   iomap_finish_ioend+0xeb/0x6a0
   blk_update_request+0x204/0x7f0
   blk_mq_end_request+0x30/0x1c0
   blk_complete_reqs+0x7e/0xa0
   __do_softirq+0x113/0x544
   __irq_exit_rcu+0xfe/0x120
   irq_exit_rcu+0xe/0x20
   sysvec_call_function_single+0x6f/0x90
   asm_sysvec_call_function_single+0x1a/0x20
   pv_native_safe_halt+0xf/0x20
   default_idle+0x9/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2b5/0x300
   cpu_startup_entry+0x34/0x40
   start_secondary+0x19d/0x1c0
   secondary_startup_64_no_verify+0x18f/0x19b
 irq event stamp: 176891
 hardirqs last  enabled at (176891): [<ffffffffa67a0be4>]
_raw_spin_unlock_irqrestore+0x44/0x60
 hardirqs last disabled at (176890): [<ffffffffa67a0899>]
_raw_spin_lock_irqsave+0x79/0xa0
 softirqs last  enabled at (176646): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120
 softirqs last disabled at (176633): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&xa->xa_lock#4);
   <Interrupt>
     lock(&xa->xa_lock#4);

  *** DEADLOCK ***

 2 locks held by test5/1708:
  #0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at:
      nfs_start_io_read+0x28/0x90 [nfs]
  #1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at:
      page_cache_ra_unbounded+0xa4/0x280

 stack backtrace:
 CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39
04/01/2014
 Call Trace:
  dump_stack_lvl+0x5b/0x90
  mark_lock+0xb3f/0xd20
  __lock_acquire+0x77b/0x3360
  _raw_spin_lock+0x34/0x80
  nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
  netfs_begin_read+0x77f/0x980 [netfs]
  nfs_netfs_readahead+0x45/0x60 [nfs]
  nfs_readahead+0x323/0x5a0 [nfs]
  read_pages+0xf3/0x5c0
  page_cache_ra_unbounded+0x1c8/0x280
  filemap_get_pages+0x38c/0xae0
  filemap_read+0x206/0x5e0
  nfs_file_read+0xb7/0x140 [nfs]
  vfs_read+0x2a9/0x460
  ksys_read+0xb7/0x140

Fixes: 000dbe0bec ("NFS: Convert buffered read paths to use netfs when fscache is enabled")
Suggested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-03-09 09:14:38 -05:00
Dai Ngo
2c35f43b5a SUNRPC: increase size of rpc_wait_queue.qlen from unsigned short to unsigned int
When the NFS client is under extreme load the rpc_wait_queue.qlen counter
can be overflowed. Here is an instant of the backlog queue overflow in a
real world environment shown by drgn helper:

rpc_task_stats(rpc_clnt):
-------------------------
rpc_clnt: 0xffff92b65d2bae00
rpc_xprt: 0xffff9275db64f000
  Queue:  sending[64887] pending[524] backlog[30441] binding[0]
XMIT task: 0xffff925c6b1d8e98
     WRITE: 750654
        __dta_call_status_580: 65463
        __dta_call_transmit_status_579: 1
        call_reserveresult: 685189
        nfs_client_init_is_complete: 1
    COMMIT: 584
        call_reserveresult: 573
        __dta_call_status_580: 11
    ACCESS: 1
        __dta_call_status_580: 1
   GETATTR: 10
        __dta_call_status_580: 4
        call_reserveresult: 6
751249 tasks for server 111.222.333.444
Total tasks: 751249

count_rpc_wait_queues(xprt):
----------------------------
**** rpc_xprt: 0xffff9275db64f000 num_reqs: 65511
wait_queue: xprt_binding[0] cnt: 0
wait_queue: xprt_binding[1] cnt: 0
wait_queue: xprt_binding[2] cnt: 0
wait_queue: xprt_binding[3] cnt: 0
rpc_wait_queue[xprt_binding].qlen: 0 maxpriority: 0
wait_queue: xprt_sending[0] cnt: 0
wait_queue: xprt_sending[1] cnt: 64887
wait_queue: xprt_sending[2] cnt: 0
wait_queue: xprt_sending[3] cnt: 0
rpc_wait_queue[xprt_sending].qlen: 64887 maxpriority: 3
wait_queue: xprt_pending[0] cnt: 524
wait_queue: xprt_pending[1] cnt: 0
wait_queue: xprt_pending[2] cnt: 0
wait_queue: xprt_pending[3] cnt: 0
rpc_wait_queue[xprt_pending].qlen: 524 maxpriority: 0
wait_queue: xprt_backlog[0] cnt: 0
wait_queue: xprt_backlog[1] cnt: 685801
wait_queue: xprt_backlog[2] cnt: 0
wait_queue: xprt_backlog[3] cnt: 0
rpc_wait_queue[xprt_backlog].qlen: 30441 maxpriority: 3 [task cnt mismatch]

There is no effect on operations when this overflow occurs. However
it causes confusion when trying to diagnose the performance problem.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:19 -05:00
Chen Hanxiao
1443f76b26 nfs: fix regression in handling of fsc= option in NFSv4
Setting the uniquifier for fscache via the fsc= mount
option is currently broken in NFSv4.

Fix this by passing fscache_uniq to root_fc if possible.

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:19 -05:00
Olga Kornievskaia
47f7c95632 pnfs/filelayout: add tracepoint to getdeviceinfo
While decoding filelayout getdeviceinfo received, print out the
information about the location of data servers (IPs).

Generic getdeviceinfo tracepoints prints the MDS's ip for the
dstaddr. In this patch, separate the MDS's address from the
DS's addresses.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:19 -05:00
Jorge Mora
bcac8bff90 NFSv4.2: fix listxattr maximum XDR buffer size
Switch order of operations to avoid creating a short XDR buffer:
e.g., buflen = 12, old xdrlen = 12, new xdrlen = 20.

Having a short XDR buffer leads to lxa_maxcount be a few bytes
less than what is needed to retrieve the whole list when using
a buflen as returned by a call with size = 0:
    buflen = listxattr(path, NULL, 0);
    buf = malloc(buflen);
    buflen = listxattr(path, buf, buflen);

For a file with one attribute (name = '123456'), the first call
with size = 0 will return buflen = 12 ('user.123456\x00').
The second call with size = 12, sends LISTXATTRS with
lxa_maxcount = 12 + 8 (cookie) + 4 (array count) = 24. The
XDR buffer needs 8 (cookie) + 4 (array count) + 4 (name count)
+ 6 (name len) + 2 (padding) + 4 (eof) = 28 which is 4 bytes
shorter than the lxa_maxcount provided in the call.

Fixes: 04a5da690e ("NFSv4.2: define limits and sizes for user xattr handling")
Signed-off-by: Jorge Mora <mora@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:18 -05:00
Jorge Mora
251a658bbf NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102
A call to listxattr() with a buffer size = 0 returns the actual
size of the buffer needed for a subsequent call. When size > 0,
nfs4_listxattr() does not return an error because either
generic_listxattr() or nfs4_listxattr_nfs4_label() consumes
exactly all the bytes then size is 0 when calling
nfs4_listxattr_nfs4_user() which then triggers the following
kernel BUG:

  [   99.403778] kernel BUG at mm/usercopy.c:102!
  [   99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
  [   99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1
  [   99.415827] Call trace:
  [   99.415985]  usercopy_abort+0x70/0xa0
  [   99.416227]  __check_heap_object+0x134/0x158
  [   99.416505]  check_heap_object+0x150/0x188
  [   99.416696]  __check_object_size.part.0+0x78/0x168
  [   99.416886]  __check_object_size+0x28/0x40
  [   99.417078]  listxattr+0x8c/0x120
  [   99.417252]  path_listxattr+0x78/0xe0
  [   99.417476]  __arm64_sys_listxattr+0x28/0x40
  [   99.417723]  invoke_syscall+0x78/0x100
  [   99.417929]  el0_svc_common.constprop.0+0x48/0xf0
  [   99.418186]  do_el0_svc+0x24/0x38
  [   99.418376]  el0_svc+0x3c/0x110
  [   99.418554]  el0t_64_sync_handler+0x120/0x130
  [   99.418788]  el0t_64_sync+0x194/0x198
  [   99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000)

Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl',
thus calling lisxattr() with size = 16 will trigger the bug.

Add check on nfs4_listxattr() to return ERANGE error when it is
called with size > 0 and the return value is greater than size.

Fixes: 012a211abd ("NFSv4.2: hook in the user extended attribute handlers")
Signed-off-by: Jorge Mora <mora@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:18 -05:00
Chen Hanxiao
490566edad NFS: Display the "fsc=" mount option if it is set
With this patch, mount command will show fsc=xxx if set:

If -o fsc=6666
clientaddr=192.168.122.208,fsc=6666,local_lock=none

If only -o fsc
clientaddr=192.168.122.208,fsc,local_lock=none

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:18 -05:00
Olga Kornievskaia
6e21eda471 SUNRPC: add xrpt id to rpc_stats_latency tracepoint
In order to get the latency per xprt under the same clientid this patch
adds xprt_id to the tracepoint output.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Tested-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:18 -05:00
Christophe JAILLET
d6f4de70f7 net: sunrpc: Fix an off by one in rpc_sockaddr2uaddr()
The intent is to check if the strings' are truncated or not. So, >= should
be used instead of >, because strlcat() and snprintf() return the length of
the output, excluding the trailing NULL.

Fixes: a02d692611 ("SUNRPC: Provide functions for managing universal addresses")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 16:18:18 -05:00
Trond Myklebust
3f7edeac0b SUNRPC: Add a transport callback to handle dequeuing of an RPC request
Add a transport level callback to allow it to handle the consequences of
dequeuing the request that was in the process of being transmitted.
For something like a TCP connection, we may need to disconnect if the
request was partially transmitted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 15:00:14 -05:00
Trond Myklebust
0c14584cdb SUNRPC: Don't try to send when the connection is shutting down
If the connection has been scheduled to shut down, we must assume that
the socket is not in a state to accept further transmissions until the
connection has been re-established.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 15:00:14 -05:00
Trond Myklebust
31d90deb65 SUNRPC: Don't retry using the same source port if connection failed
If the TCP connection attempt fails without ever establishing a
connection, then assume the problem may be the server is rejecting us
due to port reuse.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-02-28 15:00:14 -05:00
Linus Torvalds
d206a76d7d Linux 6.8-rc6 v6.8-rc6 2024-02-25 15:46:06 -08:00
Linus Torvalds
e231dbd452 Merge tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs
Pull bcachefs fixes from Kent Overstreet:
 "Some more mostly boring fixes, but some not

  User reported ones:

   - the BTREE_ITER_FILTER_SNAPSHOTS one fixes a really nasty
     performance bug; user reported an untar initially taking two
     seconds and then ~2 minutes

   - kill a __GFP_NOFAIL in the buffered read path; this was a leftover
     from the trickier fix to kill __GFP_NOFAIL in readahead, where we
     can't return errors (and have to silently truncate the read
     ourselves).

     bcachefs can't use GFP_NOFAIL for folio state unlike iomap based
     filesystems because our folio state is just barely too big, 2MB
     hugepages cause us to exceed the 2 page threshhold for GFP_NOFAIL.

     additionally, the flags argument was just buggy, we weren't
     supplying GFP_KERNEL previously (!)"

* tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs:
  bcachefs: fix bch2_save_backtrace()
  bcachefs: Fix check_snapshot() memcpy
  bcachefs: Fix bch2_journal_flush_device_pins()
  bcachefs: fix iov_iter count underflow on sub-block dio read
  bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree
  bcachefs: Kill __GFP_NOFAIL in buffered read path
  bcachefs: fix backpointer_to_text() when dev does not exist
2024-02-25 15:31:57 -08:00
Kent Overstreet
5197728f81 bcachefs: fix bch2_save_backtrace()
Missed a call in the previous fix.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-25 15:45:36 -05:00
Linus Torvalds
70ff1fe626 Merge tag 'docs-6.8-fixes3' of git://git.lwn.net/linux
Pull two documentation build fixes from Jonathan Corbet:

 - The XFS online fsck documentation uses incredibly deeply nested
   subsection and list nesting; that broke the PDF docs build. Tweak a
   parameter to tell LaTeX to allow the deeper nesting.

 - Fix a 6.8 PDF-build regression

* tag 'docs-6.8-fixes3' of git://git.lwn.net/linux:
  docs: translations: use attribute to store current language
  docs: Instruct LaTeX to cope with deeper nesting
2024-02-25 10:58:12 -08:00
Linus Torvalds
c46ac50ebe Merge tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 6.8-rc6 to resolve some reported
  problems. These include:

   - regression fixes with typec tpcm code as reported by many

   - cdnsp and cdns3 driver fixes

   - usb role setting code bugfixes

   - build fix for uhci driver

   - ncm gadget driver bugfix

   - MAINTAINERS entry update

  All of these have been in linux-next all week with no reported issues
  and there is at least one fix in here that is in Thorsten's regression
  list that is being tracked"

* tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: typec: tpcm: Fix issues with power being removed during reset
  MAINTAINERS: Drop myself as maintainer of TYPEC port controller drivers
  usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
  Revert "usb: typec: tcpm: reset counter when enter into unattached state after try role"
  usb: gadget: omap_udc: fix USB gadget regression on Palm TE
  usb: dwc3: gadget: Don't disconnect if not started
  usb: cdns3: fix memory double free when handle zero packet
  usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()
  usb: roles: don't get/set_role() when usb_role_switch is unregistered
  usb: roles: fix NULL pointer issue when put module's reference
  usb: cdnsp: fixed issue with incorrect detecting CDNSP family controllers
  usb: cdnsp: blocked some cdns3 specific code
  usb: uhci-grlib: Explicitly include linux/platform_device.h
2024-02-25 10:41:57 -08:00
Linus Torvalds
1e592e9536 Merge tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
 "Here are three small serial/tty driver fixes for 6.8-rc6 that resolve
  the following reported errors:

   - riscv hvc console driver fix that was reported by many

   - amba-pl011 serial driver fix for RS485 mode

   - stm32 serial driver fix for RS485 mode

  All of these have been in linux-next all week with no reported
  problems"

* tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: amba-pl011: Fix DMA transmission in RS485 mode
  serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled
  tty: hvc: Don't enable the RISC-V SBI console by default
2024-02-25 10:35:41 -08:00
Linus Torvalds
1eee4ef38c Merge tag 'x86_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - Make sure clearing CPU buffers using VERW happens at the latest
   possible point in the return-to-userspace path, otherwise memory
   accesses after the VERW execution could cause data to land in CPU
   buffers again

* tag 'x86_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM/VMX: Move VERW closer to VMentry for MDS mitigation
  KVM/VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH
  x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key
  x86/entry_32: Add VERW just before userspace transition
  x86/entry_64: Add VERW just before userspace transition
  x86/bugs: Add asm helpers for executing VERW
2024-02-25 10:22:21 -08:00
Linus Torvalds
8c46ed3740 Merge tag 'irq_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Borislav Petkov:

 - Make sure GICv4 always gets initialized to prevent a kexec-ed kernel
   from silently failing to set it up

 - Do not call bus_get_dev_root() for the mbigen irqchip as it always
   returns NULL - use NULL directly

 - Fix hardware interrupt number truncation when assigning MSI
   interrupts

 - Correct sending end-of-interrupt messages to disabled interrupts
   lines on RISC-V PLIC

* tag 'irq_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Do not assume vPE tables are preallocated
  irqchip/mbigen: Don't use bus_get_dev_root() to find the parent
  PCI/MSI: Prevent MSI hardware interrupt number truncation
  irqchip/sifive-plic: Enable interrupt if needed before EOI
2024-02-25 10:14:12 -08:00
Linus Torvalds
4ca0d9894f Merge tag 'erofs-for-6.8-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fix from Gao Xiang:

 - Fix page refcount leak when looking up specific inodes
   introduced by metabuf reworking

* tag 'erofs-for-6.8-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix refcount on the metabuf used for inode lookup
2024-02-25 09:53:13 -08:00
Linus Torvalds
66a97c2ec9 Merge tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull RCU pathwalk fixes from Al Viro:
 "We still have some races in filesystem methods when exposed to RCU
  pathwalk. This series is a result of code audit (the second round of
  it) and it should deal with most of that stuff.

  Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate().
  Up to maintainers (a note for NTFS folks - when documentation says
  that a method may not block, it *does* imply that blocking allocations
  are to be avoided. Really)"

[ More explanations for people who aren't familiar with the vagaries of
  RCU path walking: most of it is hidden from filesystems, but if a
  filesystem actively participates in the low-level path walking it
  needs to make sure the fields involved in that walk are RCU-safe.

  That "actively participate in low-level path walking" includes things
  like having its own ->d_hash()/->d_compare() routines, or by having
  its own directory permission function that doesn't just use the common
  helpers.  Having a ->d_revalidate() function will also have this issue.

  Note that instead of making everything RCU safe you can also choose to
  abort the RCU pathwalk if your operation cannot be done safely under
  RCU, but that obviously comes with a performance penalty. One common
  pattern is to allow the simple cases under RCU, and abort only if you
  need to do something more complicated.

  So not everything needs to be RCU-safe, and things like the inode etc
  that the VFS itself maintains obviously already are. But these fixes
  tend to be about properly RCU-delaying things like ->s_fs_info that
  are maintained by the filesystem and that got potentially released too
  early.   - Linus ]

* tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ext4_get_link(): fix breakage in RCU mode
  cifs_get_link(): bail out in unsafe case
  fuse: fix UAF in rcu pathwalks
  procfs: make freeing proc_fs_info rcu-delayed
  procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
  nfs: fix UAF on pathwalk running into umount
  nfs: make nfs_set_verifier() safe for use in RCU pathwalk
  afs: fix __afs_break_callback() / afs_drop_open_mmap() race
  hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info
  exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper
  affs: free affs_sb_info with kfree_rcu()
  rcu pathwalk: prevent bogus hard errors from may_lookup()
  fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
2024-02-25 09:29:05 -08:00
Linus Torvalds
9b24349279 Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A couple of fixes - revert of regression from this cycle and a fix for
  erofs failure exit breakage (had been there since way back)"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  erofs: fix handling kern_mount() failure
  Revert "get rid of DCACHE_GENOCIDE"
2024-02-25 09:17:15 -08:00
Al Viro
9fa8e282c2 ext4_get_link(): fix breakage in RCU mode
1) errors from ext4_getblk() should not be propagated to caller
unless we are really sure that we would've gotten the same error
in non-RCU pathwalk.
2) we leak buffer_heads if ext4_getblk() is successful, but bh is
not uptodate.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
0511fdb4a3 cifs_get_link(): bail out in unsafe case
->d_revalidate() bails out there, anyway.  It's not enough
to prevent getting into ->get_link() in RCU mode, but that
could happen only in a very contrieved setup.  Not worth
trying to do anything fancy here unless ->d_revalidate()
stops kicking out of RCU mode at least in some cases.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
053fc4f755 fuse: fix UAF in rcu pathwalks
->permission(), ->get_link() and ->inode_get_acl() might dereference
->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns
as well) when called from rcu pathwalk.

Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info
and dropping ->user_ns rcu-delayed too.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
e31f0a57ae procfs: make freeing proc_fs_info rcu-delayed
makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
47458802f6 procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
c1b967d03c nfs: fix UAF on pathwalk running into umount
NFS ->d_revalidate(), ->permission() and ->get_link() need to access
some parts of nfs_server when called in RCU mode:
	server->flags
	server->caps
	*(server->io_stats)
and, worst of all, call
	server->nfs_client->rpc_ops->have_delegation
(the last one - as NFS_PROTO(inode)->have_delegation()).  We really
don't want to RCU-delay the entire nfs_free_server() (it would have
to be done with schedule_work() from RCU callback, since it can't
be made to run from interrupt context), but actual freeing of
nfs_server and ->io_stats can be done via call_rcu() just fine.
nfs_client part is handled simply by making nfs_free_client() use
kfree_rcu().

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
10a973fc4f nfs: make nfs_set_verifier() safe for use in RCU pathwalk
nfs_set_verifier() relies upon dentry being pinned; if that's
the case, grabbing ->d_lock stabilizes ->d_parent and guarantees
that ->d_parent points to a positive dentry.  For something
we'd run into in RCU mode that is *not* true - dentry might've
been through dentry_kill() just as we grabbed ->d_lock, with
its parent going through the same just as we get to into
nfs_set_verifier_locked().  It might get to detaching inode
(and zeroing ->d_inode) before nfs_set_verifier_locked() gets
to fetching that; we get an oops as the result.

That can happen in nfs{,4} ->d_revalidate(); the call chain in
question is nfs_set_verifier_locked() <- nfs_set_verifier() <-
nfs_lookup_revalidate_delegated() <- nfs{,4}_do_lookup_revalidate().
We have checked that the parent had been positive, but that's
done before we get to nfs_set_verifier() and it's possible for
memory pressure to pick our dentry as eviction candidate by that
time.  If that happens, back-to-back attempts to kill dentry and
its parent are quite normal.  Sure, in case of eviction we'll
fail the ->d_seq check in the caller, but we need to survive
until we return there...

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:31 -05:00
Al Viro
275655d320 afs: fix __afs_break_callback() / afs_drop_open_mmap() race
In __afs_break_callback() we might check ->cb_nr_mmap and if it's non-zero
do queue_work(&vnode->cb_work).  In afs_drop_open_mmap() we decrement
->cb_nr_mmap and do flush_work(&vnode->cb_work) if it reaches zero.

The trouble is, there's nothing to prevent __afs_break_callback() from
seeing ->cb_nr_mmap before the decrement and do queue_work() after both
the decrement and flush_work().  If that happens, we might be in trouble -
vnode might get freed before the queued work runs.

__afs_break_callback() is always done under ->cb_lock, so let's make
sure that ->cb_nr_mmap can change from non-zero to zero while holding
->cb_lock (the spinlock component of it - it's a seqlock and we don't
need to mess with the counter).

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:31 -05:00