Commit graph

5 commits

Author SHA1 Message Date
Anna Schumaker
9c4dde6fa5 SUNRPC: Fix a suspicious RCU usage warning
[ Upstream commit 31b62908693c90d4d07db597e685d9f25a120073 ]

I received the following warning while running cthon against an ontap
server running pNFS:

[   57.202521] =============================
[   57.202522] WARNING: suspicious RCU usage
[   57.202523] 6.7.0-rc3-g2cc14f52aeb7 #41492 Not tainted
[   57.202525] -----------------------------
[   57.202525] net/sunrpc/xprtmultipath.c:349 RCU-list traversed in non-reader section!!
[   57.202527]
               other info that might help us debug this:

[   57.202528]
               rcu_scheduler_active = 2, debug_locks = 1
[   57.202529] no locks held by test5/3567.
[   57.202530]
               stack backtrace:
[   57.202532] CPU: 0 PID: 3567 Comm: test5 Not tainted 6.7.0-rc3-g2cc14f52aeb7 #41492 5b09971b4965c0aceba19f3eea324a4a806e227e
[   57.202534] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022
[   57.202536] Call Trace:
[   57.202537]  <TASK>
[   57.202540]  dump_stack_lvl+0x77/0xb0
[   57.202551]  lockdep_rcu_suspicious+0x154/0x1a0
[   57.202556]  rpc_xprt_switch_has_addr+0x17c/0x190 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]
[   57.202596]  rpc_clnt_setup_test_and_add_xprt+0x50/0x180 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]
[   57.202621]  ? rpc_clnt_add_xprt+0x254/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]
[   57.202646]  rpc_clnt_add_xprt+0x27a/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]
[   57.202671]  ? __pfx_rpc_clnt_setup_test_and_add_xprt+0x10/0x10 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]
[   57.202696]  nfs4_pnfs_ds_connect+0x345/0x760 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]
[   57.202728]  ? __pfx_nfs4_test_session_trunk+0x10/0x10 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]
[   57.202754]  nfs4_fl_prepare_ds+0x75/0xc0 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a]
[   57.202760]  filelayout_write_pagelist+0x4a/0x200 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a]
[   57.202765]  pnfs_generic_pg_writepages+0xbe/0x230 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]
[   57.202788]  __nfs_pageio_add_request+0x3fd/0x520 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202813]  nfs_pageio_add_request+0x18b/0x390 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202831]  nfs_do_writepage+0x116/0x1e0 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202849]  nfs_writepages_callback+0x13/0x30 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202866]  write_cache_pages+0x265/0x450
[   57.202870]  ? __pfx_nfs_writepages_callback+0x10/0x10 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202891]  nfs_writepages+0x141/0x230 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202913]  do_writepages+0xd2/0x230
[   57.202917]  ? filemap_fdatawrite_wbc+0x5c/0x80
[   57.202921]  filemap_fdatawrite_wbc+0x67/0x80
[   57.202924]  filemap_write_and_wait_range+0xd9/0x170
[   57.202930]  nfs_wb_all+0x49/0x180 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]
[   57.202947]  nfs4_file_flush+0x72/0xb0 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]
[   57.202969]  __se_sys_close+0x46/0xd0
[   57.202972]  do_syscall_64+0x68/0x100
[   57.202975]  ? do_syscall_64+0x77/0x100
[   57.202976]  ? do_syscall_64+0x77/0x100
[   57.202979]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[   57.202982] RIP: 0033:0x7fe2b12e4a94
[   57.202985] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d d5 18 0e 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 44 c3 0f 1f 00 48 83 ec 18 89 7c 24 0c e8 c3
[   57.202987] RSP: 002b:00007ffe857ddb38 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
[   57.202989] RAX: ffffffffffffffda RBX: 00007ffe857dfd68 RCX: 00007fe2b12e4a94
[   57.202991] RDX: 0000000000002000 RSI: 00007ffe857ddc40 RDI: 0000000000000003
[   57.202992] RBP: 00007ffe857dfc50 R08: 7fffffffffffffff R09: 0000000065650f49
[   57.202993] R10: 00007fe2b11f8300 R11: 0000000000000202 R12: 0000000000000000
[   57.202994] R13: 00007ffe857dfd80 R14: 00007fe2b1445000 R15: 0000000000000000
[   57.202999]  </TASK>

The problem seems to be that two out of three callers aren't taking the
rcu_read_lock() before calling the list_for_each_entry_rcu() function in
rpc_xprt_switch_has_addr(). I fix this by having
rpc_xprt_switch_has_addr() unconditionaly take the rcu_read_lock(),
which is okay to do recursively in the case that the lock has already
been taken by a caller.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:13:10 +01:00
felix
00cb8726fb SUNRPC: Fix RPC client cleaned up the freed pipefs dentries
[ Upstream commit bfca5fb4e97c46503ddfc582335917b0cc228264 ]

RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir()
workqueue,which takes care about pipefs superblock locking.
In some special scenarios, when kernel frees the pipefs sb of the
current client and immediately alloctes a new pipefs sb,
rpc_remove_pipedir function would misjudge the existence of pipefs
sb which is not the one it used to hold. As a result,
the rpc_remove_pipedir would clean the released freed pipefs dentries.

To fix this issue, rpc_remove_pipedir should check whether the
current pipefs sb is consistent with the original pipefs sb.

This error can be catched by KASAN:
=========================================================
[  250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200
[  250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503
[  250.500549] Workqueue: events rpc_free_client_work
[  250.501001] Call Trace:
[  250.502880]  kasan_report+0xb6/0xf0
[  250.503209]  ? dget_parent+0x195/0x200
[  250.503561]  dget_parent+0x195/0x200
[  250.503897]  ? __pfx_rpc_clntdir_depopulate+0x10/0x10
[  250.504384]  rpc_rmdir_depopulate+0x1b/0x90
[  250.504781]  rpc_remove_client_dir+0xf5/0x150
[  250.505195]  rpc_free_client_work+0xe4/0x230
[  250.505598]  process_one_work+0x8ee/0x13b0
...
[   22.039056] Allocated by task 244:
[   22.039390]  kasan_save_stack+0x22/0x50
[   22.039758]  kasan_set_track+0x25/0x30
[   22.040109]  __kasan_slab_alloc+0x59/0x70
[   22.040487]  kmem_cache_alloc_lru+0xf0/0x240
[   22.040889]  __d_alloc+0x31/0x8e0
[   22.041207]  d_alloc+0x44/0x1f0
[   22.041514]  __rpc_lookup_create_exclusive+0x11c/0x140
[   22.041987]  rpc_mkdir_populate.constprop.0+0x5f/0x110
[   22.042459]  rpc_create_client_dir+0x34/0x150
[   22.042874]  rpc_setup_pipedir_sb+0x102/0x1c0
[   22.043284]  rpc_client_register+0x136/0x4e0
[   22.043689]  rpc_new_client+0x911/0x1020
[   22.044057]  rpc_create_xprt+0xcb/0x370
[   22.044417]  rpc_create+0x36b/0x6c0
...
[   22.049524] Freed by task 0:
[   22.049803]  kasan_save_stack+0x22/0x50
[   22.050165]  kasan_set_track+0x25/0x30
[   22.050520]  kasan_save_free_info+0x2b/0x50
[   22.050921]  __kasan_slab_free+0x10e/0x1a0
[   22.051306]  kmem_cache_free+0xa5/0x390
[   22.051667]  rcu_core+0x62c/0x1930
[   22.051995]  __do_softirq+0x165/0x52a
[   22.052347]
[   22.052503] Last potentially related work creation:
[   22.052952]  kasan_save_stack+0x22/0x50
[   22.053313]  __kasan_record_aux_stack+0x8e/0xa0
[   22.053739]  __call_rcu_common.constprop.0+0x6b/0x8b0
[   22.054209]  dentry_free+0xb2/0x140
[   22.054540]  __dentry_kill+0x3be/0x540
[   22.054900]  shrink_dentry_list+0x199/0x510
[   22.055293]  shrink_dcache_parent+0x190/0x240
[   22.055703]  do_one_tree+0x11/0x40
[   22.056028]  shrink_dcache_for_umount+0x61/0x140
[   22.056461]  generic_shutdown_super+0x70/0x590
[   22.056879]  kill_anon_super+0x3a/0x60
[   22.057234]  rpc_kill_sb+0x121/0x200

Fixes: 0157d021d23a ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines")
Signed-off-by: felix <fuzhen5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:19 +01:00
Dan Carpenter
df37262f18 SUNRPC: Add an IS_ERR() check back to where it was
[ Upstream commit 4f3ed837186fc0d2722ba8d2457a594322e9c2ef ]

This IS_ERR() check was deleted during in a cleanup because, at the time,
the rpcb_call_async() function could not return an error pointer.  That
changed in commit 25cf32ad5dba ("SUNRPC: Handle allocation failure in
rpc_new_task()") and now it can return an error pointer.  Put the check
back.

A related revert was done in commit 13bd90141804 ("Revert "SUNRPC:
Remove unreachable error condition"").

Fixes: 037e910b52b0 ("SUNRPC: Remove unreachable error condition in rpcb_getport_async()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:19 +01:00
Trond Myklebust
63e515e6da SUNRPC: ECONNRESET might require a rebind
[ Upstream commit 4b09ca1508a60be30b2e3940264e93d7aeb5c97e ]

If connect() is returning ECONNRESET, it usually means that nothing is
listening on that port. If so, a rebind might be required in order to
obtain the new port on which the RPC service is listening.

Fixes: fd01b2597941 ("SUNRPC: ECONNREFUSED should cause a rebind.")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:43:19 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00