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In-Reply-To: <938321D5-A495-4743-831C-1150E29CB44C@oracle.com>
From:   Olga Kornievskaia <aglo@umich.edu>
Date:   Fri, 13 Nov 2020 13:49:38 -0500
Message-ID: <CAN-5tyGNrp0QDr=n06v0PSc4S=28-nE6D0J=U3eY4zb5aBTcOA@mail.gmail.com>
Subject: Re: kernel oops in generic/013 on an rdma mount (over either soft
 roce or iwarp)
To:     Chuck Lever <chuck.lever@oracle.com>,
        Frank van der Linden <fllinden@amazon.com>
Cc:     Anna Schumaker <Anna.Schumaker@netapp.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Nov 12, 2020 at 3:49 PM Chuck Lever <chuck.lever@oracle.com> wrote:
>
>
>
> > On Nov 12, 2020, at 10:37 AM, Olga Kornievskaia <aglo@umich.edu> wrote:
> >
> > On Thu, Nov 12, 2020 at 10:28 AM Chuck Lever <chuck.lever@oracle.com> wrote:
> >>
> >>
> >>
> >>> On Nov 11, 2020, at 4:42 PM, Olga Kornievskaia <aglo@umich.edu> wrote:
> >>>
> >>> On Tue, Nov 10, 2020 at 1:25 PM Chuck Lever <chuck.lever@oracle.com> wrote:
> >>>
> >>>> Start by identifying what NFS operation is failing, and what configuration
> >>>> of chunks it is using.
> >>>
> >>> This happens after decoding LIST_XATTRS reply. It's a send only reply.
> >>> I can't tell if the real problem is in the nfs4_xdr_dec_listxattrs()
> >>> and it's overwritting memory that messes with rpcrdma_complete_rqst()
> >>> or it's the rdma problem.
> >>>
> >>> Running it with Kasan shows the following:
> >>>
> >>> [  538.505743] BUG: KASAN: wild-memory-access in
> >>> rpcrdma_complete_rqst+0x41b/0x680 [rpcrdma]
> >>> [  538.512019] Write of size 8 at addr 0005088000000000 by task kworker/1:1H/493
> >>> [  538.517285]
> >>> [  538.518219] CPU: 1 PID: 493 Comm: kworker/1:1H Not tainted 5.10.0-rc3+ #33
> >>> [  538.521811] Hardware name: VMware, Inc. VMware Virtual
> >>> Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
> >>> [  538.529220] Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
> >>> [  538.532722] Call Trace:
> >>> [  538.534366]  dump_stack+0x7c/0xa2
> >>> [  538.536473]  ? rpcrdma_complete_rqst+0x41b/0x680 [rpcrdma]
> >>> [  538.539514]  ? rpcrdma_complete_rqst+0x41b/0x680 [rpcrdma]
> >>> [  538.542817]  kasan_report.cold.9+0x6a/0x7c
> >>> [  538.545952]  ? rpcrdma_complete_rqst+0x41b/0x680 [rpcrdma]
> >>> [  538.551001]  check_memory_region+0x198/0x200
> >>> [  538.553763]  memcpy+0x38/0x60
> >>> [  538.555612]  rpcrdma_complete_rqst+0x41b/0x680 [rpcrdma]
> >>> [  538.558974]  ? rpcrdma_reset_cwnd+0x70/0x70 [rpcrdma]
> >>> [  538.562162]  ? ktime_get+0x4f/0xb0
> >>> [  538.564072]  ? rpcrdma_reply_handler+0x4ca/0x640 [rpcrdma]
> >>> [  538.567066]  __ib_process_cq+0xa7/0x1f0 [ib_core]
> >>> [  538.569905]  ib_cq_poll_work+0x31/0xb0 [ib_core]
> >>> [  538.573151]  process_one_work+0x387/0x680
> >>> [  538.575798]  worker_thread+0x57/0x5a0
> >>> [  538.577917]  ? process_one_work+0x680/0x680
> >>> [  538.581095]  kthread+0x1c8/0x1f0
> >>> [  538.583271]  ? kthread_parkme+0x40/0x40
> >>> [  538.585637]  ret_from_fork+0x22/0x30
> >>> [  538.587688] ==================================================================
> >>> [  538.591920] Disabling lock debugging due to kernel taint
> >>> [  538.595267] general protection fault, probably for non-canonical
> >>> address 0x5088000000000: 0000 [#1] SMP KASAN PTI
> >>> [  538.601982] CPU: 1 PID: 3623 Comm: fsstress Tainted: G    B
> >>>   5.10.0-rc3+ #33
> >>> [  538.609032] Hardware name: VMware, Inc. VMware Virtual
> >>> Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
> >>> [  538.619678] RIP: 0010:memcpy_orig+0xf5/0x10f
> >>> [  538.623892] Code: 00 00 00 00 00 83 fa 04 72 1b 8b 0e 44 8b 44 16
> >>> fc 89 0f 44 89 44 17 fc c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 83 ea
> >>> 01 72 19 <0f> b6 0e 74 12 4c 0f b6 46 01 4c 0f b6 0c 16 44 88 47 01 44
> >>> 88 0c
> >>> [  538.636726] RSP: 0018:ffff888018707628 EFLAGS: 00010202
> >>> [  538.641125] RAX: ffff888009098855 RBX: 0000000000000008 RCX: ffffffffc19eca2d
> >>> [  538.645793] RDX: 0000000000000001 RSI: 0005088000000000 RDI: ffff888009098855
> >>> [  538.650290] RBP: 0000000000000000 R08: ffffed100121310b R09: ffffed100121310b
> >>> [  538.654879] R10: ffff888009098856 R11: ffffed100121310a R12: ffff888018707788
> >>> [  538.658700] R13: ffff888009098858 R14: ffff888009098857 R15: 0000000000000002
> >>> [  538.662871] FS:  00007f12be1c8740(0000) GS:ffff88805ca40000(0000)
> >>> knlGS:0000000000000000
> >>> [  538.667424] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >>> [  538.670768] CR2: 00007f12be1c7000 CR3: 000000005c37a004 CR4: 00000000001706e0
> >>> [  538.675865] Call Trace:
> >>> [  538.677376]  nfs4_xdr_dec_listxattrs+0x31d/0x3c0 [nfsv4]
> >>> [  538.681151]  ? nfs4_xdr_dec_read_plus+0x360/0x360 [nfsv4]
> >>> [  538.684232]  ? xdr_inline_decode+0x1e/0x260 [sunrpc]
> >>> [  538.687114]  call_decode+0x365/0x390 [sunrpc]
> >>> [  538.689626]  ? rpc_decode_header+0x770/0x770 [sunrpc]
> >>> [  538.692410]  ? var_wake_function+0x80/0x80
> >>> [  538.694634]  ?
> >>> xprt_request_retransmit_after_disconnect.isra.15+0x5e/0x80 [sunrpc]
> >>> [  538.698920]  ? rpc_decode_header+0x770/0x770 [sunrpc]
> >>> [  538.701578]  ? rpc_decode_header+0x770/0x770 [sunrpc]
> >>> [  538.704252]  __rpc_execute+0x11c/0x6e0 [sunrpc]
> >>> [  538.706829]  ? trace_event_raw_event_xprt_cong_event+0x270/0x270 [sunrpc]
> >>> [  538.710654]  ? rpc_make_runnable+0x54/0xe0 [sunrpc]
> >>> [  538.713416]  rpc_run_task+0x29c/0x2c0 [sunrpc]
> >>> [  538.715806]  nfs4_call_sync_custom+0xc/0x40 [nfsv4]
> >>> [  538.718551]  nfs4_do_call_sync+0x114/0x160 [nfsv4]
> >>> [  538.721571]  ? nfs4_call_sync_custom+0x40/0x40 [nfsv4]
> >>> [  538.724333]  ? __alloc_pages_nodemask+0x200/0x410
> >>> [  538.726794]  ? kasan_unpoison_shadow+0x30/0x40
> >>> [  538.729147]  ? __kasan_kmalloc.constprop.8+0xc1/0xd0
> >>> [  538.731733]  _nfs42_proc_listxattrs+0x1f6/0x2f0 [nfsv4]
> >>> [  538.734504]  ? nfs42_offload_cancel_done+0x50/0x50 [nfsv4]
> >>> [  538.737173]  ? __kernel_text_address+0xe/0x30
> >>> [  538.739400]  ? unwind_get_return_address+0x2f/0x50
> >>> [  538.741727]  ? create_prof_cpu_mask+0x20/0x20
> >>> [  538.744141]  ? stack_trace_consume_entry+0x80/0x80
> >>> [  538.746585]  ? _raw_spin_lock+0x7a/0xd0
> >>> [  538.748477]  nfs42_proc_listxattrs+0xf4/0x150 [nfsv4]
> >>> [  538.750920]  ? nfs42_proc_setxattr+0x150/0x150 [nfsv4]
> >>> [  538.753557]  ? nfs4_xattr_cache_list+0x91/0x120 [nfsv4]
> >>> [  538.756313]  nfs4_listxattr+0x34d/0x3d0 [nfsv4]
> >>> [  538.758506]  ? _nfs4_proc_access+0x260/0x260 [nfsv4]
> >>> [  538.760859]  ? __ia32_sys_rename+0x40/0x40
> >>> [  538.762897]  ? selinux_quota_on+0xf0/0xf0
> >>> [  538.764827]  ? __check_object_size+0x178/0x220
> >>> [  538.767063]  ? kasan_unpoison_shadow+0x30/0x40
> >>> [  538.769233]  ? security_inode_listxattr+0x53/0x60
> >>> [  538.771962]  listxattr+0x5b/0xf0
> >>> [  538.773980]  path_listxattr+0xa1/0x100
> >>> [  538.776147]  ? listxattr+0xf0/0xf0
> >>> [  538.778064]  do_syscall_64+0x33/0x40
> >>> [  538.780714]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >>> [  538.783440] RIP: 0033:0x7f12bdaebc8b
> >>> [  538.785341] Code: f0 ff ff 73 01 c3 48 8b 0d fa 21 2c 00 f7 d8 64
> >>> 89 01 48 83 c8 ff c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 c2 00 00
> >>> 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d cd 21 2c 00 f7 d8 64 89
> >>> 01 48
> >>> [  538.794845] RSP: 002b:00007ffc7947cff8 EFLAGS: 00000206 ORIG_RAX:
> >>> 00000000000000c2
> >>> [  538.798985] RAX: ffffffffffffffda RBX: 0000000001454650 RCX: 00007f12bdaebc8b
> >>> [  538.802840] RDX: 0000000000000018 RSI: 000000000145c150 RDI: 0000000001454650
> >>> [  538.807093] RBP: 000000000145c150 R08: 00007f12bddaeba0 R09: 00007ffc7947cc46
> >>> [  538.811487] R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000002dd
> >>> [  538.816713] R13: 0000000000000018 R14: 0000000000000018 R15: 0000000000000000
> >>> [  538.820437] Modules linked in: rpcrdma rdma_rxe ip6_udp_tunnel
> >>> udp_tunnel rdma_ucm rdma_cm iw_cm ib_cm ib_uverbs ib_core cts
> >>> rpcsec_gss_krb5 nfsv4 dns_resolver nfs lockd grace nfs_ssc nls_utf8
> >>> isofs fuse rfcomm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib
> >>> nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct
> >>> nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 tun bridge stp llc
> >>> ip6_tables nft_compat ip_set nf_tables nfnetlink bnep
> >>> vmw_vsock_vmci_transport vsock snd_seq_midi snd_seq_midi_event
> >>> intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul
> >>> vmw_balloon ghash_clmulni_intel joydev pcspkr btusb uvcvideo btrtl
> >>> btbcm btintel videobuf2_vmalloc videobuf2_memops videobuf2_v4l2
> >>> videobuf2_common snd_ens1371 snd_ac97_codec ac97_bus snd_seq snd_pcm
> >>> videodev bluetooth mc rfkill ecdh_generic ecc snd_timer snd_rawmidi
> >>> snd_seq_device snd soundcore vmw_vmci i2c_piix4 auth_rpcgss sunrpc
> >>> ip_tables xfs libcrc32c sr_mod cdrom sg crc32c_intel ata_generic
> >>> serio_raw nvme vmwgfx drm_kms_helper
> >>> [  538.820577]  syscopyarea sysfillrect sysimgblt fb_sys_fops cec
> >>> nvme_core t10_pi ata_piix ahci libahci ttm vmxnet3 drm libata
> >>> [  538.869541] ---[ end trace 4abb2d95a72e9aab ]---
> >>
> >> I'm running a v5.10-rc3 client now with the fix applied and
> >> KASAN enabled. I traced my xfstests run and I'm definitely
> >> exercising the LISTXATTRS path:
> >>
> >> # trace-cmd report -F rpc_request | grep LISTXATTR | wc -l
> >> 462
> >>
> >> No crash or KASAN splat. I'm still missing something.
> >>
> >> I sometimes apply small patches from the mailing list by hand
> >> editing the modified file. Are you sure you applied my fix
> >> correctly?
> >
> > Again I think the difference is the SoftRoce vs hardware
>
> I'm not finding that plausible... Can you troubleshoot this further
> to demonstrate how soft RoCE is contributing to this issue?

Btw I'm not the only one. Anna's tests are failing too.

OK so all this started with xattr patches (Trond's tags/nfs-for-5.9-1
don't pass the generic/013). Your patch isn't sufficient to fix it.
When I increased decode_listxattrs_maxsz by 5 then Oops went away (but
that's a hack). Here's a fix on top of your fix that allows for my
tests to run.

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index d0ddf90c9be4..49573b285946 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -179,7 +179,7 @@
                                 1 + nfs4_xattr_name_maxsz + 1)
 #define decode_setxattr_maxsz   (op_decode_hdr_maxsz +
decode_change_info_maxsz)
 #define encode_listxattrs_maxsz  (op_encode_hdr_maxsz + 2 + 1)
-#define decode_listxattrs_maxsz  (op_decode_hdr_maxsz + 2 + 1 + 1 + 1)
+#define decode_listxattrs_maxsz  (op_decode_hdr_maxsz + 2 + 1 + 1 + 5)
 #define encode_removexattr_maxsz (op_encode_hdr_maxsz + 1 + \
                                  nfs4_xattr_name_maxsz)
 #define decode_removexattr_maxsz (op_decode_hdr_maxsz + \

I would like Frank to comment on what the decode_listattrs_maxsz
should be. According to the RFC:

/// struct LISTXATTRS4resok {
   ///         nfs_cookie4    lxr_cookie;
   ///         xattrkey4      lxr_names<>;
   ///         bool           lxr_eof;
   /// };

This is current code (with Chuck's fix): op_decode_hdr_maxsz + 2 + 1 + 1 + 1

I don't see how the xattrkey4  lxr_names<> can be estimated by a
constant number. So I think the real fix should be:

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index d0ddf90c9be4..73b44f8c036d 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -179,7 +179,8 @@
                                 1 + nfs4_xattr_name_maxsz + 1)
 #define decode_setxattr_maxsz   (op_decode_hdr_maxsz +
decode_change_info_maxsz)
 #define encode_listxattrs_maxsz  (op_encode_hdr_maxsz + 2 + 1)
-#define decode_listxattrs_maxsz  (op_decode_hdr_maxsz + 2 + 1 + 1 + 1)
+#define decode_listxattrs_maxsz  (op_decode_hdr_maxsz + 2 + 1 + 1 + \
+                                 XDR_QUADLEN(NFS4_OPAQUE_LIMIT))
 #define encode_removexattr_maxsz (op_encode_hdr_maxsz + 1 + \
                                  nfs4_xattr_name_maxsz)
 #define decode_removexattr_maxsz (op_decode_hdr_maxsz + \


>

>
> --
> Chuck Lever
>
>
>