mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity
linux-stable/net/sunrpc
History
Anna Schumaker fece80a2a6 SUNRPC: Fix a suspicious RCU usage warning 
[ Upstream commit 31b6290869 ]

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>
 		2024-02-23 08:12:45 +01:00
..
auth_gss SUNRPC: ensure the matching upcall is in-flight upon downcall 2023-01-18 11:30:49 +01:00
xprtrdma xprtrdma: fix incorrect header size calculations 2022-06-25 11:49:18 +02:00
Kconfig
…
Makefile
…
addr.c net: sunrpc: interpret the return value of kstrtou32 correctly 2021-01-19 18:22:38 +01:00
auth.c
…
auth_generic.c SUNRPC: Fix a bogus get/put in generic_key_to_expire() 2018-12-01 09:37:33 +01:00
auth_null.c
…
auth_unix.c
…
backchannel_rqst.c SUNRPC: Reinitialise the backchannel request buffers before reuse 2022-08-25 11:15:37 +02:00
cache.c sunrpc: fix crash when cache_head become valid before update 2019-12-17 20:35:52 +01:00
clnt.c SUNRPC: remove the maximum number of retries in call_bind_status 2023-05-17 11:13:19 +02:00
debugfs.c
…
netns.h
…
rpc_pipe.c sunrpc: fixed rollback in rpc_gssd_dummy_populate() 2020-06-30 23:17:18 -04:00
rpcb_clnt.c SUNRPC: stop printk reading past end of string 2020-09-23 12:10:58 +02:00
sched.c SUNRPC: remove the maximum number of retries in call_bind_status 2023-05-17 11:13:19 +02:00
socklib.c
…
stats.c
…
sunrpc.h
…
sunrpc_syms.c
…
svc.c SUNRPC/nfs: Fix return value for nfs4_callback_compound() 2021-09-22 11:47:47 +02:00
svc_xprt.c NFSD: Repair misuse of sv_lock in 5.10.16-rt30. 2021-03-24 11:07:33 +01:00
svcauth.c
…
svcauth_unix.c
…
svcsock.c SUNRPC: Fix UAF in svc_tcp_listen_data_ready() 2023-08-11 11:45:20 +02:00
sysctl.c
…
timer.c
…
xdr.c SUNRPC: Fix READ_PLUS crasher 2022-07-07 17:35:09 +02:00
xprt.c SUNRPC: use _bh spinlocking on ->transport_lock 2022-09-15 12:17:06 +02:00
xprtmultipath.c SUNRPC: Fix a suspicious RCU usage warning 2024-02-23 08:12:45 +01:00
xprtsock.c Revert "SUNRPC: attempt AF_LOCAL connect on setup" 2022-05-12 12:20:24 +02:00