linux/net/sunrpc, branch v3.4.101

nfsd: check passed socket's net matches NFSd superblock's one

2014-06-11T19:04:19Z

commit 3064639423c48d6e0eb9ecc27c512a58e38c6c57 upstream. There could be a case, when NFSd file system is mounted in network, different to socket's one, like below: "ip netns exec" creates new network and mount namespace, which duplicates NFSd mount point, created in init_net context. And thus NFS server stop in nested network context leads to RPCBIND client destruction in init_net. Then, on NFSd start in nested network context, rpc.nfsd process creates socket in nested net and passes it into "write_ports", which leads to RPCBIND sockets creation in init_net context because of the same reason (NFSd monut point was created in init_net context). An attempt to register passed socket in nested net leads to panic, because no RPCBIND client present in nexted network namespace. This patch add check that passed socket's net matches NFSd superblock's one. And returns -EINVAL error to user psace otherwise. v2: Put socket on exit. Reported-by: Weng Meiling Signed-off-by: Stanislav Kinsbursky Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields [wengmeiling: backport to 3.4: adjust context] Signed-off-by: Weng Meiling Signed-off-by: Greg Kroah-Hartman

SUNRPC: Prevent an rpc_task wakeup race

2014-03-11T23:10:08Z

commit a3c3cac5d31879cd9ae2de7874dc6544ca704aec upstream. The lockless RPC_IS_QUEUED() test in __rpc_execute means that we need to be careful about ordering the calls to rpc_test_and_set_running(task) and rpc_clear_queued(task). If we get the order wrong, then we may end up testing the RPC_TASK_RUNNING flag after __rpc_execute() has looped and changed the state of the rpc_task. Signed-off-by: Trond Myklebust Signed-off-by: Ben Hutchings Cc: Weng Meiling Signed-off-by: Greg Kroah-Hartman

sunrpc: clarify comments on rpc_make_runnable

2014-03-11T23:10:07Z

commit 506026c3ec270e18402f0c9d33fee37482c23861 upstream. rpc_make_runnable is not generally called with the queue lock held, unless it's waking up a task that has been sitting on a waitqueue. This is safe when the task has not entered the FSM yet, but the comments don't really spell this out. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Ben Hutchings Cc: Weng Meiling Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix races in xs_nospace()

2014-03-11T23:10:00Z

commit 06ea0bfe6e6043cb56a78935a19f6f8ebc636226 upstream. When a send failure occurs due to the socket being out of buffer space, we call xs_nospace() in order to have the RPC task wait until the socket has drained enough to make it worth while trying again. The current patch fixes a race in which the socket is drained before we get round to setting up the machinery in xs_nospace(), and which is reported to cause hangs. Link: http://lkml.kernel.org/r/20140210170315.33dfc621@notabene.brown Fixes: a9a6b52ee1ba (SUNRPC: Don't start the retransmission timer...) Reported-by: Neil Brown Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

sunrpc: Fix infinite loop in RPC state machine

2014-02-13T19:51:13Z

commit 6ff33b7dd0228b7d7ed44791bbbc98b03fd15d9d upstream. When a task enters call_refreshresult with status 0 from call_refresh and !rpcauth_uptodatecred(task) it enters call_refresh again with no rate-limiting or max number of retries. Instead of trying forever, make use of the retry path that other errors use. This only seems to be possible when the crrefresh callback is gss_refresh_null, which only happens when destroying the context. To reproduce: 1) mount with sec=krb5 (or sec=sys with krb5 negotiated for non FSID specific operations). 2) reboot - the client will be stuck and will need to be hard rebooted BUG: soft lockup - CPU#0 stuck for 22s! [kworker/0:2:46] Modules linked in: rpcsec_gss_krb5 nfsv4 nfs fscache ppdev crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd serio_raw i2c_piix4 i2c_core e1000 parport_pc parport shpchp nfsd auth_rpcgss oid_registry exportfs nfs_acl lockd sunrpc autofs4 mptspi scsi_transport_spi mptscsih mptbase ata_generic floppy irq event stamp: 195724 hardirqs last enabled at (195723): [] restore_args+0x0/0x30 hardirqs last disabled at (195724): [] apic_timer_interrupt+0x6a/0x80 softirqs last enabled at (195722): [] __do_softirq+0x1df/0x276 softirqs last disabled at (195717): [] irq_exit+0x53/0x9a CPU: 0 PID: 46 Comm: kworker/0:2 Not tainted 3.13.0-rc3-branch-dros_testing+ #4 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Workqueue: rpciod rpc_async_schedule [sunrpc] task: ffff8800799c4260 ti: ffff880079002000 task.ti: ffff880079002000 RIP: 0010:[] [] __rpc_execute+0x8a/0x362 [sunrpc] RSP: 0018:ffff880079003d18 EFLAGS: 00000246 RAX: 0000000000000005 RBX: 0000000000000007 RCX: 0000000000000007 RDX: 0000000000000007 RSI: ffff88007aecbae8 RDI: ffff8800783d8900 RBP: ffff880079003d78 R08: ffff88006e30e9f8 R09: ffffffffa005a3d7 R10: ffff88006e30e7b0 R11: ffff8800783d8900 R12: ffffffffa006675e R13: ffff880079003ce8 R14: ffff88006e30e7b0 R15: ffff8800783d8900 FS: 0000000000000000(0000) GS:ffff88007f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3072333000 CR3: 0000000001a0b000 CR4: 00000000001407f0 Stack: ffff880079003d98 0000000000000246 0000000000000000 ffff88007a9a4830 ffff880000000000 ffffffff81073f47 ffff88007f212b00 ffff8800799c4260 ffff8800783d8988 ffff88007f212b00 ffffe8ffff604800 0000000000000000 Call Trace: [] ? trace_hardirqs_on_caller+0x145/0x1a1 [] rpc_async_schedule+0x27/0x32 [sunrpc] [] process_one_work+0x211/0x3a5 [] ? process_one_work+0x172/0x3a5 [] worker_thread+0x134/0x202 [] ? rescuer_thread+0x280/0x280 [] ? rescuer_thread+0x280/0x280 [] kthread+0xc9/0xd1 [] ? __kthread_parkme+0x61/0x61 [] ret_from_fork+0x7c/0xb0 [] ? __kthread_parkme+0x61/0x61 Code: e8 87 63 fd e0 c6 05 10 dd 01 00 01 48 8b 43 70 4c 8d 6b 70 45 31 e4 a8 02 0f 85 d5 02 00 00 4c 8b 7b 48 48 c7 43 48 00 00 00 00 <4c> 8b 4b 50 4d 85 ff 75 0c 4d 85 c9 4d 89 cf 0f 84 32 01 00 00 And the output of "rpcdebug -m rpc -s all": RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refresh (status 0) RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refresh (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 RPC: 61 call_refreshresult (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refresh (status 0) RPC: 61 call_refreshresult (status 0) RPC: 61 refreshing RPCSEC_GSS cred ffff88007a413cf0 Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a data corruption issue when retransmitting RPC calls

2013-11-29T18:50:36Z

commit a6b31d18b02ff9d7915c5898c9b5ca41a798cd73 upstream. The following scenario can cause silent data corruption when doing NFS writes. It has mainly been observed when doing database writes using O_DIRECT. 1) The RPC client uses sendpage() to do zero-copy of the page data. 2) Due to networking issues, the reply from the server is delayed, and so the RPC client times out. 3) The client issues a second sendpage of the page data as part of an RPC call retransmission. 4) The reply to the first transmission arrives from the server _before_ the client hardware has emptied the TCP socket send buffer. 5) After processing the reply, the RPC state machine rules that the call to be done, and triggers the completion callbacks. 6) The application notices the RPC call is done, and reuses the pages to store something else (e.g. a new write). 7) The client NIC drains the TCP socket send buffer. Since the page data has now changed, it reads a corrupted version of the initial RPC call, and puts it on the wire. This patch fixes the problem in the following manner: The ordering guarantees of TCP ensure that when the server sends a reply, then we know that the _first_ transmission has completed. Using zero-copy in that situation is therefore safe. If a time out occurs, we then send the retransmission using sendmsg() (i.e. no zero-copy), We then know that the socket contains a full copy of the data, and so it will retransmit a faithful reproduction even if the RPC call completes, and the application reuses the O_DIRECT buffer in the meantime. Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

SUNRPC: don't map EKEYEXPIRED to EACCES in call_refreshresult

2013-11-29T18:50:33Z

commit f1ff0c27fd9987c59d707cd1a6b6c1fc3ae0a250 upstream. The NFS layer needs to know when a key has expired. This change also returns -EKEYEXPIRED to the application, and the informative "Key has expired" error message is displayed. The user then knows that credential renewal is required. Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

SUNRPC handle EKEYEXPIRED in call_refreshresult

2013-11-29T18:50:32Z

commit eb96d5c97b0825d542e9c4ba5e0a22b519355166 upstream. Currently, when an RPCSEC_GSS context has expired or is non-existent and the users (Kerberos) credentials have also expired or are non-existent, the client receives the -EKEYEXPIRED error and tries to refresh the context forever. If an application is performing I/O, or other work against the share, the application hangs, and the user is not prompted to refresh/establish their credentials. This can result in a denial of service for other users. Users are expected to manage their Kerberos credential lifetimes to mitigate this issue. Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number of times to refresh the gss_context, and then return -EACCES to the application. Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust [bwh: Backported to 3.2: - Adjust context - Drop change to nfs4_handle_reclaim_lease_error()] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix memory corruption issue on 32-bit highmem systems

2013-09-08T04:58:15Z

commit 347e2233b7667e336d9f671f1a52dfa3f0416e2c upstream. Some architectures, such as ARM-32 do not return the same base address when you call kmap_atomic() twice on the same page. This causes problems for the memmove() call in the XDR helper routine "_shift_data_right_pages()", since it defeats the detection of overlapping memory ranges, and has been seen to corrupt memory. The fix is to distinguish between the case where we're doing an inter-page copy or not. In the former case of we know that the memory ranges cannot possibly overlap, so we can additionally micro-optimise by replacing memmove() with memcpy(). Reported-by: Mark Young Reported-by: Matt Craighead Cc: Bruce Fields Signed-off-by: Trond Myklebust Tested-by: Matt Craighead Signed-off-by: Greg Kroah-Hartman

SUNRPC: Add barriers to ensure read ordering in rpc_wake_up_task_queue_locked

2013-04-05T17:04:14Z

commit 1166fde6a923c30f4351515b6a9a1efc513e7d00 upstream. We need to be careful when testing task->tk_waitqueue in rpc_wake_up_task_queue_locked, because it can be changed while we are holding the queue->lock. By adding appropriate memory barriers, we can ensure that it is safe to test task->tk_waitqueue for equality if the RPC_TASK_QUEUED bit is set. Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman