linux-stable.git/net, branch v3.4.83 Linux kernel stable tree SUNRPC: Prevent an rpc_task wakeup race 2014-03-11T23:10:08+00:00 Trond Myklebust Trond.Myklebust@netapp.com 2013-05-22T16:57:24+00:00 d4d811d55f75e02ae7beaea3dc611498bf2bf5fb 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 <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sunrpc: clarify comments on rpc_make_runnable 2014-03-11T23:10:07+00:00 Jeff Layton jlayton@redhat.com 2012-07-23T19:51:55+00:00 e8d5ce17375e2ece50659f287ad1a3daf2335d7e 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 <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libceph: unregister request in __map_request failed and nofail == false 2014-03-11T23:10:05+00:00 majianpeng majianpeng@gmail.com 2013-07-16T07:45:48+00:00 b3f19e7fb89f09ca56324a06b4ef7caf6745259b commit 73d9f7eef3d98c3920e144797cc1894c6b005a1e upstream. For nofail == false request, if __map_request failed, the caller does cleanup work, like releasing the relative pages. It doesn't make any sense to retry this request. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Reviewed-by: Sage Weil <sage@inktank.com> [bwh: Backported to 3.2: adjust indentation] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 73d9f7eef3d98c3920e144797cc1894c6b005a1e upstream.

For nofail == false request, if __map_request failed, the caller does
cleanup work, like releasing the relative pages.  It doesn't make any sense
to retry this request.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>
[bwh: Backported to 3.2: adjust indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SUNRPC: Fix races in xs_nospace() 2014-03-11T23:10:00+00:00 Trond Myklebust trond.myklebust@primarydata.com 2014-02-11T14:15:54+00:00 5dd00a93ea27897deb79e23797f7ced6910e7979 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 <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ip, ipv6: handle gso skbs in forwarding path 2014-03-11T23:09:59+00:00 Florian Westphal fw@strlen.de 2014-02-22T09:33:26+00:00 29a3cd46644ec8098dbe1c12f89643b5c11831a9 commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream. [ use zero netdev_feature mask to avoid backport of netif_skb_dev_features function ] Marcelo Ricardo Leitner reported problems when the forwarding link path has a lower mtu than the incoming one if the inbound interface supports GRO. Given: Host <mtu1500> R1 <mtu1200> R2 Host sends tcp stream which is routed via R1 and R2. R1 performs GRO. In this case, the kernel will fail to send ICMP fragmentation needed messages (or pkt too big for ipv6), as GSO packets currently bypass dstmtu checks in forward path. Instead, Linux tries to send out packets exceeding the mtu. When locking route MTU on Host (i.e., no ipv4 DF bit set), R1 does not fragment the packets when forwarding, and again tries to send out packets exceeding R1-R2 link mtu. This alters the forwarding dstmtu checks to take the individual gso segment lengths into account. For ipv6, we send out pkt too big error for gso if the individual segments are too big. For ipv4, we either send icmp fragmentation needed, or, if the DF bit is not set, perform software segmentation and let the output path create fragments when the packet is leaving the machine. It is not 100% correct as the error message will contain the headers of the GRO skb instead of the original/segmented one, but it seems to work fine in my (limited) tests. Eric Dumazet suggested to simply shrink mss via ->gso_size to avoid sofware segmentation. However it turns out that skb_segment() assumes skb nr_frags is related to mss size so we would BUG there. I don't want to mess with it considering Herbert and Eric disagree on what the correct behavior should be. Hannes Frederic Sowa notes that when we would shrink gso_size skb_segment would then also need to deal with the case where SKB_MAX_FRAGS would be exceeded. This uses sofware segmentation in the forward path when we hit ipv4 non-DF packets and the outgoing link mtu is too small. Its not perfect, but given the lack of bug reports wrt. GRO fwd being broken this is a rare case anyway. Also its not like this could not be improved later once the dust settles. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Reported-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.

[ use zero netdev_feature mask to avoid backport of
  netif_skb_dev_features function ]

Marcelo Ricardo Leitner reported problems when the forwarding link path
has a lower mtu than the incoming one if the inbound interface supports GRO.

Given:
Host <mtu1500> R1 <mtu1200> R2

Host sends tcp stream which is routed via R1 and R2.  R1 performs GRO.

In this case, the kernel will fail to send ICMP fragmentation needed
messages (or pkt too big for ipv6), as GSO packets currently bypass dstmtu
checks in forward path. Instead, Linux tries to send out packets exceeding
the mtu.

When locking route MTU on Host (i.e., no ipv4 DF bit set), R1 does
not fragment the packets when forwarding, and again tries to send out
packets exceeding R1-R2 link mtu.

This alters the forwarding dstmtu checks to take the individual gso
segment lengths into account.

For ipv6, we send out pkt too big error for gso if the individual
segments are too big.

For ipv4, we either send icmp fragmentation needed, or, if the DF bit
is not set, perform software segmentation and let the output path
create fragments when the packet is leaving the machine.
It is not 100% correct as the error message will contain the headers of
the GRO skb instead of the original/segmented one, but it seems to
work fine in my (limited) tests.

Eric Dumazet suggested to simply shrink mss via ->gso_size to avoid
sofware segmentation.

However it turns out that skb_segment() assumes skb nr_frags is related
to mss size so we would BUG there.  I don't want to mess with it considering
Herbert and Eric disagree on what the correct behavior should be.

Hannes Frederic Sowa notes that when we would shrink gso_size
skb_segment would then also need to deal with the case where
SKB_MAX_FRAGS would be exceeded.

This uses sofware segmentation in the forward path when we hit ipv4
non-DF packets and the outgoing link mtu is too small.  Its not perfect,
but given the lack of bug reports wrt. GRO fwd being broken this is a
rare case anyway.  Also its not like this could not be improved later
once the dust settles.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: add and use skb_gso_transport_seglen() 2014-03-11T23:09:59+00:00 Florian Westphal fw@strlen.de 2014-02-22T09:33:25+00:00 32e66c065179e598c0e692f4d57ded48715e0d99 commit de960aa9ab4decc3304959f69533eef64d05d8e8 upstream. [ no skb_gso_seglen helper in 3.4, leave tbf alone ] This moves part of Eric Dumazets skb_gso_seglen helper from tbf sched to skbuff core so it may be reused by upcoming ip forwarding path patch. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit de960aa9ab4decc3304959f69533eef64d05d8e8 upstream.

[ no skb_gso_seglen helper in 3.4, leave tbf alone ]

This moves part of Eric Dumazets skb_gso_seglen helper from tbf sched to
skbuff core so it may be reused by upcoming ip forwarding path patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: sctp: fix sctp_connectx abi for ia32 emulation/compat mode 2014-03-11T23:09:59+00:00 Daniel Borkmann dborkman@redhat.com 2014-02-17T11:11:11+00:00 19e48381ab5da05c5fb398336a90a52a2b623cdc [ Upstream commit ffd5939381c609056b33b7585fb05a77b4c695f3 ] SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of 'struct sctp_getaddrs_old' which includes a struct sockaddr pointer, sizeof(param) check will always fail in kernel as the structure in 64bit kernel space is 4bytes larger than for user binaries compiled in 32bit mode. Thus, applications making use of sctp_connectx() won't be able to run under such circumstances. Introduce a compat interface in the kernel to deal with such situations by using a 'struct compat_sctp_getaddrs_old' structure where user data is copied into it, and then sucessively transformed into a 'struct sctp_getaddrs_old' structure with the help of compat_ptr(). That fixes sctp_connectx() abi without any changes needed in user space, and lets the SCTP test suite pass when compiled in 32bit and run on 64bit kernels. Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit ffd5939381c609056b33b7585fb05a77b4c695f3 ]

SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit
emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of
'struct sctp_getaddrs_old' which includes a struct sockaddr pointer,
sizeof(param) check will always fail in kernel as the structure in
64bit kernel space is 4bytes larger than for user binaries compiled
in 32bit mode. Thus, applications making use of sctp_connectx() won't
be able to run under such circumstances.

Introduce a compat interface in the kernel to deal with such
situations by using a 'struct compat_sctp_getaddrs_old' structure
where user data is copied into it, and then sucessively transformed
into a 'struct sctp_getaddrs_old' structure with the help of
compat_ptr(). That fixes sctp_connectx() abi without any changes
needed in user space, and lets the SCTP test suite pass when compiled
in 32bit and run on 64bit kernels.

Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: fix 'ip rule' iif/oif device rename 2014-03-11T23:09:58+00:00 Maciej Żenczykowski maze@google.com 2014-02-08T00:23:48+00:00 d4f0afc9ecf77da7da6e1e5a8b35ce8067bdf0dc [ Upstream commit 946c032e5a53992ea45e062ecb08670ba39b99e3 ] ip rules with iif/oif references do not update: (detach/attach) across interface renames. Signed-off-by: Maciej Żenczykowski <maze@google.com> CC: Willem de Bruijn <willemb@google.com> CC: Eric Dumazet <edumazet@google.com> CC: Chris Davis <chrismd@google.com> CC: Carlo Contavalli <ccontavalli@google.com> Google-Bug-Id: 12936021 Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 946c032e5a53992ea45e062ecb08670ba39b99e3 ]

ip rules with iif/oif references do not update:
(detach/attach) across interface renames.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
CC: Willem de Bruijn <willemb@google.com>
CC: Eric Dumazet <edumazet@google.com>
CC: Chris Davis <chrismd@google.com>
CC: Carlo Contavalli <ccontavalli@google.com>
Google-Bug-Id: 12936021
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mac80211: fix fragmentation code, particularly for encryption 2014-02-22T18:32:45+00:00 Johannes Berg johannes.berg@intel.com 2014-01-31T23:16:23+00:00 fb11ab59b2999e2afee7c7fcd3687bf07b2fc988 commit 338f977f4eb441e69bb9a46eaa0ac715c931a67f upstream. The "new" fragmentation code (since my rewrite almost 5 years ago) erroneously sets skb->len rather than using skb_trim() to adjust the length of the first fragment after copying out all the others. This leaves the skb tail pointer pointing to after where the data originally ended, and thus causes the encryption MIC to be written at that point, rather than where it belongs: immediately after the data. The impact of this is that if software encryption is done, then a) encryption doesn't work for the first fragment, the connection becomes unusable as the first fragment will never be properly verified at the receiver, the MIC is practically guaranteed to be wrong b) we leak up to 8 bytes of plaintext (!) of the packet out into the air This is only mitigated by the fact that many devices are capable of doing encryption in hardware, in which case this can't happen as the tail pointer is irrelevant in that case. Additionally, fragmentation is not used very frequently and would normally have to be configured manually. Fix this by using skb_trim() properly. Fixes: 2de8e0d999b8 ("mac80211: rewrite fragmentation") Reported-by: Jouni Malinen <j@w1.fi> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 338f977f4eb441e69bb9a46eaa0ac715c931a67f upstream.

The "new" fragmentation code (since my rewrite almost 5 years ago)
erroneously sets skb->len rather than using skb_trim() to adjust
the length of the first fragment after copying out all the others.
This leaves the skb tail pointer pointing to after where the data
originally ended, and thus causes the encryption MIC to be written
at that point, rather than where it belongs: immediately after the
data.

The impact of this is that if software encryption is done, then
 a) encryption doesn't work for the first fragment, the connection
    becomes unusable as the first fragment will never be properly
    verified at the receiver, the MIC is practically guaranteed to
    be wrong
 b) we leak up to 8 bytes of plaintext (!) of the packet out into
    the air

This is only mitigated by the fact that many devices are capable
of doing encryption in hardware, in which case this can't happen
as the tail pointer is irrelevant in that case. Additionally,
fragmentation is not used very frequently and would normally have
to be configured manually.

Fix this by using skb_trim() properly.

Fixes: 2de8e0d999b8 ("mac80211: rewrite fragmentation")
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sunrpc: Fix infinite loop in RPC state machine 2014-02-13T19:51:13+00:00 Weston Andros Adamson dros@netapp.com 2013-12-17T17:16:11+00:00 b0c0d5a3ee2a62e5cbeef3e2089bbd624e6869fa 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): [<ffffffff814a925c>] restore_args+0x0/0x30 hardirqs last disabled at (195724): [<ffffffff814b0a6a>] apic_timer_interrupt+0x6a/0x80 softirqs last enabled at (195722): [<ffffffff8103f583>] __do_softirq+0x1df/0x276 softirqs last disabled at (195717): [<ffffffff8103f852>] 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:[<ffffffffa0064fd4>] [<ffffffffa0064fd4>] __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: [<ffffffff81073f47>] ? trace_hardirqs_on_caller+0x145/0x1a1 [<ffffffffa00652d3>] rpc_async_schedule+0x27/0x32 [sunrpc] [<ffffffff81052974>] process_one_work+0x211/0x3a5 [<ffffffff810528d5>] ? process_one_work+0x172/0x3a5 [<ffffffff81052eeb>] worker_thread+0x134/0x202 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280 [<ffffffff810584a0>] kthread+0xc9/0xd1 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61 [<ffffffff814afd6c>] ret_from_fork+0x7c/0xb0 [<ffffffff810583d7>] ? __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 <dros@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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): [<ffffffff814a925c>] restore_args+0x0/0x30
hardirqs last disabled at (195724): [<ffffffff814b0a6a>] apic_timer_interrupt+0x6a/0x80
softirqs last  enabled at (195722): [<ffffffff8103f583>] __do_softirq+0x1df/0x276
softirqs last disabled at (195717): [<ffffffff8103f852>] 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:[<ffffffffa0064fd4>]  [<ffffffffa0064fd4>] __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:
 [<ffffffff81073f47>] ? trace_hardirqs_on_caller+0x145/0x1a1
 [<ffffffffa00652d3>] rpc_async_schedule+0x27/0x32 [sunrpc]
 [<ffffffff81052974>] process_one_work+0x211/0x3a5
 [<ffffffff810528d5>] ? process_one_work+0x172/0x3a5
 [<ffffffff81052eeb>] worker_thread+0x134/0x202
 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280
 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280
 [<ffffffff810584a0>] kthread+0xc9/0xd1
 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61
 [<ffffffff814afd6c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810583d7>] ? __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 <dros@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>