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  1. 11 8月, 2018 4 次提交
    • M
      bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT · 2dbb9b9e
      由 Martin KaFai Lau 提交于 
      This patch adds a BPF_PROG_TYPE_SK_REUSEPORT which can select
a SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY.  Like other
non SK_FILTER/CGROUP_SKB program, it requires CAP_SYS_ADMIN.

BPF_PROG_TYPE_SK_REUSEPORT introduces "struct sk_reuseport_kern"
to store the bpf context instead of using the skb->cb[48].

At the SO_REUSEPORT sk lookup time, it is in the middle of transiting
from a lower layer (ipv4/ipv6) to a upper layer (udp/tcp).  At this
point,  it is not always clear where the bpf context can be appended
in the skb->cb[48] to avoid saving-and-restoring cb[].  Even putting
aside the difference between ipv4-vs-ipv6 and udp-vs-tcp.  It is not
clear if the lower layer is only ipv4 and ipv6 in the future and
will it not touch the cb[] again before transiting to the upper
layer.

For example, in udp_gro_receive(), it uses the 48 byte NAPI_GRO_CB
instead of IP[6]CB and it may still modify the cb[] after calling
the udp[46]_lib_lookup_skb().  Because of the above reason, if
sk->cb is used for the bpf ctx, saving-and-restoring is needed
and likely the whole 48 bytes cb[] has to be saved and restored.

Instead of saving, setting and restoring the cb[], this patch opts
to create a new "struct sk_reuseport_kern" and setting the needed
values in there.

The new BPF_PROG_TYPE_SK_REUSEPORT and "struct sk_reuseport_(kern|md)"
will serve all ipv4/ipv6 + udp/tcp combinations.  There is no protocol
specific usage at this point and it is also inline with the current
sock_reuseport.c implementation (i.e. no protocol specific requirement).

In "struct sk_reuseport_md", this patch exposes data/data_end/len
with semantic similar to other existing usages.  Together
with "bpf_skb_load_bytes()" and "bpf_skb_load_bytes_relative()",
the bpf prog can peek anywhere in the skb.  The "bind_inany" tells
the bpf prog that the reuseport group is bind-ed to a local
INANY address which cannot be learned from skb.

The new "bind_inany" is added to "struct sock_reuseport" which will be
used when running the new "BPF_PROG_TYPE_SK_REUSEPORT" bpf prog in order
to avoid repeating the "bind INANY" test on
"sk_v6_rcv_saddr/sk->sk_rcv_saddr" every time a bpf prog is run.  It can
only be properly initialized when a "sk->sk_reuseport" enabled sk is
adding to a hashtable (i.e. during "reuseport_alloc()" and
"reuseport_add_sock()").

The new "sk_select_reuseport()" is the main helper that the
bpf prog will use to select a SO_REUSEPORT sk.  It is the only function
that can use the new BPF_MAP_TYPE_REUSEPORT_ARRAY.  As mentioned in
the earlier patch, the validity of a selected sk is checked in
run time in "sk_select_reuseport()".  Doing the check in
verification time is difficult and inflexible (consider the map-in-map
use case).  The runtime check is to compare the selected sk's reuseport_id
with the reuseport_id that we want.  This helper will return -EXXX if the
selected sk cannot serve the incoming request (e.g. reuseport_id
not match).  The bpf prog can decide if it wants to do SK_DROP as its
discretion.

When the bpf prog returns SK_PASS, the kernel will check if a
valid sk has been selected (i.e. "reuse_kern->selected_sk != NULL").
If it does , it will use the selected sk.  If not, the kernel
will select one from "reuse->socks[]" (as before this patch).

The SK_DROP and SK_PASS handling logic will be in the next patch.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      2dbb9b9e
    • M
      bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY · 5dc4c4b7
      由 Martin KaFai Lau 提交于 
      This patch introduces a new map type BPF_MAP_TYPE_REUSEPORT_SOCKARRAY.

To unleash the full potential of a bpf prog, it is essential for the
userspace to be capable of directly setting up a bpf map which can then
be consumed by the bpf prog to make decision.  In this case, decide which
SO_REUSEPORT sk to serve the incoming request.

By adding BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, the userspace has total control
and visibility on where a SO_REUSEPORT sk should be located in a bpf map.
The later patch will introduce BPF_PROG_TYPE_SK_REUSEPORT such that
the bpf prog can directly select a sk from the bpf map.  That will
raise the programmability of the bpf prog attached to a reuseport
group (a group of sk serving the same IP:PORT).

For example, in UDP, the bpf prog can peek into the payload (e.g.
through the "data" pointer introduced in the later patch) to learn
the application level's connection information and then decide which sk
to pick from a bpf map.  The userspace can tightly couple the sk's location
in a bpf map with the application logic in generating the UDP payload's
connection information.  This connection info contact/API stays within the
userspace.

Also, when used with map-in-map, the userspace can switch the
old-server-process's inner map to a new-server-process's inner map
in one call "bpf_map_update_elem(outer_map, &index, &new_reuseport_array)".
The bpf prog will then direct incoming requests to the new process instead
of the old process.  The old process can finish draining the pending
requests (e.g. by "accept()") before closing the old-fds.  [Note that
deleting a fd from a bpf map does not necessary mean the fd is closed]

During map_update_elem(),
Only SO_REUSEPORT sk (i.e. which has already been added
to a reuse->socks[]) can be used.  That means a SO_REUSEPORT sk that is
"bind()" for UDP or "bind()+listen()" for TCP.  These conditions are
ensured in "reuseport_array_update_check()".

A SO_REUSEPORT sk can only be added once to a map (i.e. the
same sk cannot be added twice even to the same map).  SO_REUSEPORT
already allows another sk to be created for the same IP:PORT.
There is no need to re-create a similar usage in the BPF side.

When a SO_REUSEPORT is deleted from the "reuse->socks[]" (e.g. "close()"),
it will notify the bpf map to remove it from the map also.  It is
done through "bpf_sk_reuseport_detach()" and it will only be called
if >=1 of the "reuse->sock[]" has ever been added to a bpf map.

The map_update()/map_delete() has to be in-sync with the
"reuse->socks[]".  Hence, the same "reuseport_lock" used
by "reuse->socks[]" has to be used here also. Care has
been taken to ensure the lock is only acquired when the
adding sk passes some strict tests. and
freeing the map does not require the reuseport_lock.

The reuseport_array will also support lookup from the syscall
side.  It will return a sock_gen_cookie().  The sock_gen_cookie()
is on-demand (i.e. a sk's cookie is not generated until the very
first map_lookup_elem()).

The lookup cookie is 64bits but it goes against the logical userspace
expectation on 32bits sizeof(fd) (and as other fd based bpf maps do also).
It may catch user in surprise if we enforce value_size=8 while
userspace still pass a 32bits fd during update.  Supporting different
value_size between lookup and update seems unintuitive also.

We also need to consider what if other existing fd based maps want
to return 64bits value from syscall's lookup in the future.
Hence, reuseport_array supports both value_size 4 and 8, and
assuming user will usually use value_size=4.  The syscall's lookup
will return ENOSPC on value_size=4.  It will will only
return 64bits value from sock_gen_cookie() when user consciously
choose value_size=8 (as a signal that lookup is desired) which then
requires a 64bits value in both lookup and update.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      5dc4c4b7
    • M
      net: Add ID (if needed) to sock_reuseport and expose reuseport_lock · 736b4602
      由 Martin KaFai Lau 提交于 
      A later patch will introduce a BPF_MAP_TYPE_REUSEPORT_ARRAY which
allows a SO_REUSEPORT sk to be added to a bpf map.  When a sk
is removed from reuse->socks[], it also needs to be removed from
the bpf map.  Also, when adding a sk to a bpf map, the bpf
map needs to ensure it is indeed in a reuse->socks[].
Hence, reuseport_lock is needed by the bpf map to ensure its
map_update_elem() and map_delete_elem() operations are in-sync with
the reuse->socks[].  The BPF_MAP_TYPE_REUSEPORT_ARRAY map will only
acquire the reuseport_lock after ensuring the adding sk is already
in a reuseport group (i.e. reuse->socks[]).  The map_lookup_elem()
will be lockless.

This patch also adds an ID to sock_reuseport.  A later patch
will introduce BPF_PROG_TYPE_SK_REUSEPORT which allows
a bpf prog to select a sk from a bpf map.  It is inflexible to
statically enforce a bpf map can only contain the sk belonging to
a particular reuse->socks[] (i.e. same IP:PORT) during the bpf
verification time. For example, think about the the map-in-map situation
where the inner map can be dynamically changed in runtime and the outer
map may have inner maps belonging to different reuseport groups.
Hence, when the bpf prog (in the new BPF_PROG_TYPE_SK_REUSEPORT
type) selects a sk,  this selected sk has to be checked to ensure it
belongs to the requesting reuseport group (i.e. the group serving
that IP:PORT).

The "sk->sk_reuseport_cb" pointer cannot be used for this checking
purpose because the pointer value will change after reuseport_grow().
Instead of saving all checking conditions like the ones
preced calling "reuseport_add_sock()" and compare them everytime a
bpf_prog is run, a 32bits ID is introduced to survive the
reuseport_grow().  The ID is only acquired if any of the
reuse->socks[] is added to the newly introduced
"BPF_MAP_TYPE_REUSEPORT_ARRAY" map.

If "BPF_MAP_TYPE_REUSEPORT_ARRAY" is not used,  the changes in this
patch is a no-op.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      736b4602
    • M
      tcp: Avoid TCP syncookie rejected by SO_REUSEPORT socket · 40a1227e
      由 Martin KaFai Lau 提交于 
      Although the actual cookie check "__cookie_v[46]_check()" does
not involve sk specific info, it checks whether the sk has recent
synq overflow event in "tcp_synq_no_recent_overflow()".  The
tcp_sk(sk)->rx_opt.ts_recent_stamp is updated every second
when it has sent out a syncookie (through "tcp_synq_overflow()").

The above per sk "recent synq overflow event timestamp" works well
for non SO_REUSEPORT use case.  However, it may cause random
connection request reject/discard when SO_REUSEPORT is used with
syncookie because it fails the "tcp_synq_no_recent_overflow()"
test.

When SO_REUSEPORT is used, it usually has multiple listening
socks serving TCP connection requests destinated to the same local IP:PORT.
There are cases that the TCP-ACK-COOKIE may not be received
by the same sk that sent out the syncookie.  For example,
if reuse->socks[] began with {sk0, sk1},
1) sk1 sent out syncookies and tcp_sk(sk1)->rx_opt.ts_recent_stamp
   was updated.
2) the reuse->socks[] became {sk1, sk2} later.  e.g. sk0 was first closed
   and then sk2 was added.  Here, sk2 does not have ts_recent_stamp set.
   There are other ordering that will trigger the similar situation
   below but the idea is the same.
3) When the TCP-ACK-COOKIE comes back, sk2 was selected.
   "tcp_synq_no_recent_overflow(sk2)" returns true. In this case,
   all syncookies sent by sk1 will be handled (and rejected)
   by sk2 while sk1 is still alive.

The userspace may create and remove listening SO_REUSEPORT sockets
as it sees fit.  E.g. Adding new thread (and SO_REUSEPORT sock) to handle
incoming requests, old process stopping and new process starting...etc.
With or without SO_ATTACH_REUSEPORT_[CB]BPF,
the sockets leaving and joining a reuseport group makes picking
the same sk to check the syncookie very difficult (if not impossible).

The later patches will allow bpf prog more flexibility in deciding
where a sk should be located in a bpf map and selecting a particular
SO_REUSEPORT sock as it sees fit.  e.g. Without closing any sock,
replace the whole bpf reuseport_array in one map_update() by using
map-in-map.  Getting the syncookie check working smoothly across
socks in the same "reuse->socks[]" is important.

A partial solution is to set the newly added sk's ts_recent_stamp
to the max ts_recent_stamp of a reuseport group but that will require
to iterate through reuse->socks[]  OR
pessimistically set it to "now - TCP_SYNCOOKIE_VALID" when a sk is
joining a reuseport group.  However, neither of them will solve the
existing sk getting moved around the reuse->socks[] and that
sk may not have ts_recent_stamp updated, unlikely under continuous
synflood but not impossible.

This patch opts to treat the reuseport group as a whole when
considering the last synq overflow timestamp since
they are serving the same IP:PORT from the userspace
(and BPF program) perspective.

"synq_overflow_ts" is added to "struct sock_reuseport".
The tcp_synq_overflow() and tcp_synq_no_recent_overflow()
will update/check reuse->synq_overflow_ts if the sk is
in a reuseport group.  Similar to the reuseport decision in
__inet_lookup_listener(), both sk->sk_reuseport and
sk->sk_reuseport_cb are tested for SO_REUSEPORT usage.
Update on "synq_overflow_ts" happens at roughly once
every second.

A synflood test was done with a 16 rx-queues and 16 reuseport sockets.
No meaningful performance change is observed.  Before and
after the change is ~9Mpps in IPv4.

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      40a1227e
  3. 10 8月, 2018 4 次提交
  5. 09 8月, 2018 7 次提交
    • A
      dsa: slave: eee: Allow ports to use phylink · 1be52e97
      由 Andrew Lunn 提交于 
      For a port to be able to use EEE, both the MAC and the PHY must
support EEE. A phy can be provided by both a phydev or phylink. Verify
at least one of these exist, not just phydev.

Fixes: aab9c406 ("net: dsa: Plug in PHYLINK support")
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1be52e97
    • U
      net/smc: move sock lock in smc_ioctl() · 7311d665
      由 Ursula Braun 提交于 
      When an SMC socket is connecting it is decided whether fallback to
TCP is needed. To avoid races between connect and ioctl move the
sock lock before the use_fallback check.

Reported-by: syzbot+5b2cece1a8ecb2ca77d8@syzkaller.appspotmail.com
Reported-by: syzbot+19557374321ca3710990@syzkaller.appspotmail.com
Fixes: 1992d998 ("net/smc: take sock lock in smc_ioctl()")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7311d665
    • U
      net/smc: allow sysctl rmem and wmem defaults for servers · bd58c7e0
      由 Ursula Braun 提交于 
      Without setsockopt SO_SNDBUF and SO_RCVBUF settings, the sysctl
defaults net.ipv4.tcp_wmem and net.ipv4.tcp_rmem should be the base
for the sizes of the SMC sndbuf and rcvbuf. Any TCP buffer size
optimizations for servers should be ignored.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bd58c7e0
    • U
      net/smc: no shutdown in state SMC_LISTEN · caa21e19
      由 Ursula Braun 提交于 
      Invoking shutdown for a socket in state SMC_LISTEN does not make
sense. Nevertheless programs like syzbot fuzzing the kernel may
try to do this. For SMC this means a socket refcounting problem.
This patch makes sure a shutdown call for an SMC socket in state
SMC_LISTEN simply returns with -ENOTCONN.
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      caa21e19
    • D
      rxrpc: Fix the keepalive generator [ver #2] · 330bdcfa
      由 David Howells 提交于 
      AF_RXRPC has a keepalive message generator that generates a message for a
peer ~20s after the last transmission to that peer to keep firewall ports
open.  The implementation is incorrect in the following ways:

 (1) It mixes up ktime_t and time64_t types.

 (2) It uses ktime_get_real(), the output of which may jump forward or
     backward due to adjustments to the time of day.

 (3) If the current time jumps forward too much or jumps backwards, the
     generator function will crank the base of the time ring round one slot
     at a time (ie. a 1s period) until it catches up, spewing out VERSION
     packets as it goes.

Fix the problem by:

 (1) Only using time64_t.  There's no need for sub-second resolution.

 (2) Use ktime_get_seconds() rather than ktime_get_real() so that time
     isn't perceived to go backwards.

 (3) Simplifying rxrpc_peer_keepalive_worker() by splitting it into two
     parts:

     (a) The "worker" function that manages the buckets and the timer.

     (b) The "dispatch" function that takes the pending peers and
     	 potentially transmits a keepalive packet before putting them back
     	 in the ring into the slot appropriate to the revised last-Tx time.

 (4) Taking everything that's pending out of the ring and splicing it into
     a temporary collector list for processing.

     In the case that there's been a significant jump forward, the ring
     gets entirely emptied and then the time base can be warped forward
     before the peers are processed.

     The warping can't happen if the ring isn't empty because the slot a
     peer is in is keepalive-time dependent, relative to the base time.

 (5) Limit the number of iterations of the bucket array when scanning it.

 (6) Set the timer to skip any empty slots as there's no point waking up if
     there's nothing to do yet.

This can be triggered by an incoming call from a server after a reboot with
AF_RXRPC and AFS built into the kernel causing a peer record to be set up
before userspace is started.  The system clock is then adjusted by
userspace, thereby potentially causing the keepalive generator to have a
meltdown - which leads to a message like:

	watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/0:1:23]
	...
	Workqueue: krxrpcd rxrpc_peer_keepalive_worker
	EIP: lock_acquire+0x69/0x80
	...
	Call Trace:
	 ? rxrpc_peer_keepalive_worker+0x5e/0x350
	 ? _raw_spin_lock_bh+0x29/0x60
	 ? rxrpc_peer_keepalive_worker+0x5e/0x350
	 ? rxrpc_peer_keepalive_worker+0x5e/0x350
	 ? __lock_acquire+0x3d3/0x870
	 ? process_one_work+0x110/0x340
	 ? process_one_work+0x166/0x340
	 ? process_one_work+0x110/0x340
	 ? worker_thread+0x39/0x3c0
	 ? kthread+0xdb/0x110
	 ? cancel_delayed_work+0x90/0x90
	 ? kthread_stop+0x70/0x70
	 ? ret_from_fork+0x19/0x24

Fixes: ace45bec ("rxrpc: Fix firewall route keepalive")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      330bdcfa
    • Z
      net:mod: remove unneeded variable 'ret' in init_p9 · 5a0c6cee
      由 zhong jiang 提交于 
      The ret is modified after initalization, so just remove it and
return 0.
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5a0c6cee
    • Z
      net:af_iucv: get rid of the unneeded variable 'err' in afiucv_pm_freeze · fb3b467e
      由 zhong jiang 提交于 
      We will not use the variable 'err' after initalization, So remove it and
return 0.
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fb3b467e
  7. 08 8月, 2018 9 次提交
    • C
      llc: use refcount_inc_not_zero() for llc_sap_find() · 0dcb8225
      由 Cong Wang 提交于 
      llc_sap_put() decreases the refcnt before deleting sap
from the global list. Therefore, there is a chance
llc_sap_find() could find a sap with zero refcnt
in this global list.

Close this race condition by checking if refcnt is zero
or not in llc_sap_find(), if it is zero then it is being
removed so we can just treat it as gone.

Reported-by: <syzbot+278893f3f7803871f7ce@syzkaller.appspotmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0dcb8225
    • A
      dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart() · 61ef4b07
      由 Alexey Kodanev 提交于 
      The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value
can lead to undefined behavior [1].

In order to fix this use a gradual shift of the window with a 'while'
loop, similar to what tcp_cwnd_restart() is doing.

When comparing delta and RTO there is a minor difference between TCP
and DCCP, the last one also invokes dccp_cwnd_restart() and reduces
'cwnd' if delta equals RTO. That case is preserved in this change.

[1]:
[40850.963623] UBSAN: Undefined behaviour in net/dccp/ccids/ccid2.c:237:7
[40851.043858] shift exponent 67 is too large for 32-bit type 'unsigned int'
[40851.127163] CPU: 3 PID: 15940 Comm: netstress Tainted: G        W   E     4.18.0-rc7.x86_64 #1
...
[40851.377176] Call Trace:
[40851.408503]  dump_stack+0xf1/0x17b
[40851.451331]  ? show_regs_print_info+0x5/0x5
[40851.503555]  ubsan_epilogue+0x9/0x7c
[40851.548363]  __ubsan_handle_shift_out_of_bounds+0x25b/0x2b4
[40851.617109]  ? __ubsan_handle_load_invalid_value+0x18f/0x18f
[40851.686796]  ? xfrm4_output_finish+0x80/0x80
[40851.739827]  ? lock_downgrade+0x6d0/0x6d0
[40851.789744]  ? xfrm4_prepare_output+0x160/0x160
[40851.845912]  ? ip_queue_xmit+0x810/0x1db0
[40851.895845]  ? ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40851.963530]  ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40852.029063]  dccp_xmit_packet+0x1d3/0x720 [dccp]
[40852.086254]  dccp_write_xmit+0x116/0x1d0 [dccp]
[40852.142412]  dccp_sendmsg+0x428/0xb20 [dccp]
[40852.195454]  ? inet_dccp_listen+0x200/0x200 [dccp]
[40852.254833]  ? sched_clock+0x5/0x10
[40852.298508]  ? sched_clock+0x5/0x10
[40852.342194]  ? inet_create+0xdf0/0xdf0
[40852.388988]  sock_sendmsg+0xd9/0x160
...

Fixes: 113ced1f ("dccp ccid-2: Perform congestion-window validation")
Signed-off-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      61ef4b07
    • Y
      RDS: IB: fix 'passing zero to ERR_PTR()' warning · 5941923d
      由 YueHaibing 提交于 
      Fix a static code checker warning:
 net/rds/ib_frmr.c:82 rds_ib_alloc_frmr() warn: passing zero to 'ERR_PTR'

The error path for ib_alloc_mr failure should set err to PTR_ERR.

Fixes: 1659185f ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5941923d
    • Y
      tipc: fix an interrupt unsafe locking scenario · 37436d9c
      由 Ying Xue 提交于 
      Commit 9faa89d4 ("tipc: make function tipc_net_finalize() thread
safe") tries to make it thread safe to set node address, so it uses
node_list_lock lock to serialize the whole process of setting node
address in tipc_net_finalize(). But it causes the following interrupt
unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rht_deferred_worker()
  rhashtable_rehash_table()
  lock(&(&ht->lock)->rlock)
			       tipc_nl_compat_doit()
                               tipc_net_finalize()
                               local_irq_disable();
                               lock(&(&tn->node_list_lock)->rlock);
                               tipc_sk_reinit()
                               rhashtable_walk_enter()
                               lock(&(&ht->lock)->rlock);
  <Interrupt>
  tipc_disc_rcv()
  tipc_node_check_dest()
  tipc_node_create()
  lock(&(&tn->node_list_lock)->rlock);

 *** DEADLOCK ***

When rhashtable_rehash_table() holds ht->lock on CPU0, it doesn't
disable BH. So if an interrupt happens after the lock, it can create
an inverse lock ordering between ht->lock and tn->node_list_lock. As
a consequence, deadlock might happen.

The reason causing the inverse lock ordering scenario above is because
the initial purpose of node_list_lock is not designed to do the
serialization of node address setting.

As cmpxchg() can guarantee CAS (compare-and-swap) process is atomic,
we use it to replace node_list_lock to ensure setting node address can
be atomically finished. It turns out the potential deadlock can be
avoided as well.

Fixes: 9faa89d4 ("tipc: make function tipc_net_finalize() thread safe")
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <maloy@donjonn.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      37436d9c
    • C
      vsock: split dwork to avoid reinitializations · 455f05ec
      由 Cong Wang 提交于 
      syzbot reported that we reinitialize an active delayed
work in vsock_stream_connect():

	ODEBUG: init active (active state 0) object type: timer_list hint:
	delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:1414
	WARNING: CPU: 1 PID: 11518 at lib/debugobjects.c:329
	debug_print_object+0x16a/0x210 lib/debugobjects.c:326

The pattern is apparently wrong, we should only initialize
the dealyed work once and could repeatly schedule it. So we
have to move out the initializations to allocation side.
And to avoid confusion, we can split the shared dwork
into two, instead of re-using the same one.

Fixes: d021c344 ("VSOCK: Introduce VM Sockets")
Reported-by: <syzbot+8a9b1bd330476a4f3db6@syzkaller.appspotmail.com>
Cc: Andy king <acking@vmware.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      455f05ec
    • S
      ip6_tunnel: collect_md xmit: Use ip_tunnel_key's provided src address · 3789caba
      由 Shmulik Ladkani 提交于 
      When using an ip6tnl device in collect_md mode, the xmit methods ignore
the ipv6.src field present in skb_tunnel_info's key, both for route
calculation purposes (flowi6 construction) and for assigning the
packet's final ipv6h->saddr.

This makes it impossible specifying a desired ipv6 local address in the
encapsulating header (for example, when using tc action tunnel_key).

This is also not aligned with behavior of ipip (ipv4) in collect_md
mode, where the key->u.ipv4.src gets used.

Fix, by assigning fl6.saddr with given key->u.ipv6.src.
In case ipv6.src is not specified, ip6_tnl_xmit uses existing saddr
selection code.

Fixes: 8d79266b ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: NEyal Birger <eyal.birger@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3789caba
    • V
      net: sched: cls_flower: set correct offload data in fl_reoffload · 9ca61630
      由 Vlad Buslov 提交于 
      fl_reoffload implementation sets following members of struct
tc_cls_flower_offload incorrectly:
 - masked key instead of mask
 - key instead of masked key

Fix fl_reoffload to provide correct data to offload callback.

Fixes: 31533cba ("net: sched: cls_flower: implement offload tcf_proto_op")
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9ca61630
    • P
      net/sched: allow flower to match tunnel options · 0a6e7778
      由 Pieter Jansen van Vuuren 提交于 
      Allow matching on options in Geneve tunnel headers.
This makes use of existing tunnel metadata support.

The options can be described in the form
CLASS:TYPE:DATA/CLASS_MASK:TYPE_MASK:DATA_MASK, where CLASS is
represented as a 16bit hexadecimal value, TYPE as an 8bit
hexadecimal value and DATA as a variable length hexadecimal value.

e.g.
 # ip link add name geneve0 type geneve dstport 0 external
 # tc qdisc add dev geneve0 ingress
 # tc filter add dev geneve0 protocol ip parent ffff: \
     flower \
       enc_src_ip 10.0.99.192 \
       enc_dst_ip 10.0.99.193 \
       enc_key_id 11 \
       geneve_opts 0102:80:1122334421314151/ffff:ff:ffffffffffffffff \
       ip_proto udp \
       action mirred egress redirect dev eth1

This patch adds support for matching Geneve options in the order
supplied by the user. This leads to an efficient implementation in
the software datapath (and in our opinion hardware datapaths that
offload this feature). It is also compatible with Geneve options
matching provided by the Open vSwitch kernel datapath which is
relevant here as the Flower classifier may be used as a mechanism
to program flows into hardware as a form of Open vSwitch datapath
offload (sometimes referred to as OVS-TC). The netlink
Kernel/Userspace API may be extended, for example by adding a flag,
if other matching options are desired, for example matching given
options in any order. This would require an implementation in the
TC software datapath. And be done in a way that drivers that
facilitate offload of the Flower classifier can reject or accept
such flows based on hardware datapath capabilities.

This approach was discussed and agreed on at Netconf 2017 in Seoul.
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0a6e7778
    • S
      flow_dissector: allow dissection of tunnel options from metadata · 92e2c405
      由 Simon Horman 提交于 
      Allow the existing 'dissection' of tunnel metadata to 'dissect'
options already present in tunnel metadata. This dissection is
controlled by a new dissector key, FLOW_DISSECTOR_KEY_ENC_OPTS.

This dissection only occurs when skb_flow_dissect_tunnel_info()
is called, currently only the Flower classifier makes that call.
So there should be no impact on other users of the flow dissector.

This is in preparation for allowing the flower classifier to
match on Geneve options.
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      92e2c405
  9. 07 8月, 2018 4 次提交
  11. 06 8月, 2018 12 次提交