[ Upstream commit bfd07f3dd4 ]
When sending multicast messages via blocking socket,
if sending link is congested (tsk->cong_link_cnt is set to 1),
the sending thread will be put into sleeping state. However,
tipc_sk_filter_rcv() is called under socket spin lock but
tipc_wait_for_cond() is not. So, there is no guarantee that
the setting of tsk->cong_link_cnt to 0 in tipc_sk_proto_rcv() in
CPU-1 will be perceived by CPU-0. If that is the case, the sending
thread in CPU-0 after being waken up, will continue to see
tsk->cong_link_cnt as 1 and put the sending thread into sleeping
state again. The sending thread will sleep forever.
CPU-0 | CPU-1
tipc_wait_for_cond() |
{ |
// condition_ = !tsk->cong_link_cnt |
while ((rc_ = !(condition_))) { |
... |
release_sock(sk_); |
wait_woken(); |
| if (!sock_owned_by_user(sk))
| tipc_sk_filter_rcv()
| {
| ...
| tipc_sk_proto_rcv()
| {
| ...
| tsk->cong_link_cnt--;
| ...
| sk->sk_write_space(sk);
| ...
| }
| ...
| }
sched_annotate_sleep(); |
lock_sock(sk_); |
remove_wait_queue(); |
} |
} |
This commit fixes it by adding memory barrier to tipc_sk_proto_rcv()
and tipc_wait_for_cond().
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0e63208915 ]
Fix regression bug introduced in
commit 365ad353c2 ("tipc: reduce risk of user starvation during link
congestion")
Only signal -EDESTADDRREQ for RDM/DGRAM if we don't have a cached
sockaddr.
Fixes: 365ad353c2 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f5d6c3e5a3 ]
When setting LINK tolerance, node timer interval will be calculated
base on the LINK with lowest tolerance.
But when calculated, the old node timer interval only updated if current
setting value (tolerance/4) less than old ones regardless of number of
links as well as links' lowest tolerance value.
This caused to two cases missing if tolerance changed as following:
Case 1:
1.1/ There is one link (L1) available in the system
1.2/ Set L1's tolerance from 1500ms => lower (i.e 500ms)
1.3/ Then, fallback to default (1500ms) or higher (i.e 2000ms)
Expected:
node timer interval is 1500/4=375ms after 1.3
Result:
node timer interval will not being updated after changing tolerance at 1.3
since its value 1500/4=375ms is not less than 500/4=125ms at 1.2.
Case 2:
2.1/ There are two links (L1, L2) available in the system
2.2/ L1 and L2 tolerance value are 2000ms as initial
2.3/ Set L2's tolerance from 2000ms => lower 1500ms
2.4/ Disable link L2 (bring down its bearer)
Expected:
node timer interval is 2000ms/4=500ms after 2.4
Result:
node timer interval will not being updated after disabling L2 since
its value 2000ms/4=500ms is still not less than 1500/4=375ms at 2.3
although L2 is already not available in the system.
To fix this, we start the node interval calculation by initializing it to
a value larger than any conceivable calculated value. This way, the link
with the lowest tolerance will always determine the calculated value.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2753ca5d90 upstream.
BUG: KMSAN: uninit-value in tipc_nl_compat_doit+0x404/0xa10 net/tipc/netlink_compat.c:335
CPU: 0 PID: 4514 Comm: syz-executor485 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
tipc_nl_compat_doit+0x404/0xa10 net/tipc/netlink_compat.c:335
tipc_nl_compat_recv+0x164b/0x2700 net/tipc/netlink_compat.c:1153
genl_family_rcv_msg net/netlink/genetlink.c:599 [inline]
genl_rcv_msg+0x1686/0x1810 net/netlink/genetlink.c:624
netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2447
genl_rcv+0x63/0x80 net/netlink/genetlink.c:635
netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
netlink_unicast+0x166b/0x1740 net/netlink/af_netlink.c:1337
netlink_sendmsg+0x1048/0x1310 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:630 [inline]
sock_sendmsg net/socket.c:640 [inline]
___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
__sys_sendmsg net/socket.c:2080 [inline]
SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
SyS_sendmsg+0x54/0x80 net/socket.c:2087
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x43fda9
RSP: 002b:00007ffd0c184ba8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fda9
RDX: 0000000000000000 RSI: 0000000020023000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 00000000004016d0
R13: 0000000000401760 R14: 0000000000000000 R15: 0000000000000000
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
slab_post_alloc_hook mm/slab.h:445 [inline]
slab_alloc_node mm/slub.c:2737 [inline]
__kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
__kmalloc_reserve net/core/skbuff.c:138 [inline]
__alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
alloc_skb include/linux/skbuff.h:984 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
netlink_sendmsg+0x9a6/0x1310 net/netlink/af_netlink.c:1875
sock_sendmsg_nosec net/socket.c:630 [inline]
sock_sendmsg net/socket.c:640 [inline]
___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
__sys_sendmsg net/socket.c:2080 [inline]
SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
SyS_sendmsg+0x54/0x80 net/socket.c:2087
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
In tipc_nl_compat_recv(), when the len variable returned by
nlmsg_attrlen() is 0, the message is still treated as a valid one,
which is obviously unresonable. When len is zero, it means the
message not only doesn't contain any valid TLV payload, but also
TLV header is not included. Under this stituation, tlv_type field
in TLV header is still accessed in tipc_nl_compat_dumpit() or
tipc_nl_compat_doit(), but the field space is obviously illegal.
Of course, it is not initialized.
Reported-by: syzbot+bca0dc46634781f08b38@syzkaller.appspotmail.com
Reported-by: syzbot+6bdb590321a7ae40c1a6@syzkaller.appspotmail.com
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a88289f4dd upstream.
syzbot reported:
BUG: KMSAN: uninit-value in tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373
CPU: 0 PID: 66 Comm: kworker/u4:4 Not tainted 4.17.0-rc3+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: tipc_rcv tipc_conn_recv_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:113
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
tipc_conn_rcv_sub+0x184/0x950 net/tipc/topsrv.c:373
tipc_conn_rcv_from_sock net/tipc/topsrv.c:409 [inline]
tipc_conn_recv_work+0x3cd/0x560 net/tipc/topsrv.c:424
process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145
worker_thread+0x113c/0x24f0 kernel/workqueue.c:2279
kthread+0x539/0x720 kernel/kthread.c:239
ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:412
Local variable description: ----s.i@tipc_conn_recv_work
Variable was created at:
tipc_conn_recv_work+0x65/0x560 net/tipc/topsrv.c:419
process_one_work+0x12c6/0x1f60 kernel/workqueue.c:2145
In tipc_conn_rcv_from_sock(), it always supposes the length of message
received from sock_recvmsg() is not smaller than the size of struct
tipc_subscr. However, this assumption is false. Especially when the
length of received message is shorter than struct tipc_subscr size,
we will end up touching uninitialized fields in tipc_conn_rcv_sub().
Reported-by: syzbot+8951a3065ee7fd6d6e23@syzkaller.appspotmail.com
Reported-by: syzbot+75e6e042c5bbf691fc82@syzkaller.appspotmail.com
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc_wait_for_cond() drops socket lock before going to sleep,
but tsk->group could be freed right after that release_sock().
So we have to re-check and reload tsk->group after it wakes up.
After this patch, tipc_wait_for_cond() returns -ERESTARTSYS when
tsk->group is NULL, instead of continuing with the assumption of
a non-NULL tsk->group.
(It looks like 'dsts' should be re-checked and reloaded too, but
it is a different bug.)
Similar for tipc_send_group_unicast() and tipc_send_group_anycast().
Reported-by: syzbot+10a9db47c3a0e13eb31c@syzkaller.appspotmail.com
Fixes: b7d4263551 ("tipc: introduce flow control for group broadcast messages")
Fixes: ee106d7f94 ("tipc: introduce group anycast messaging")
Fixes: 27bd9ec027 ("tipc: introduce group unicast messaging")
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lock_sock() must be used in process context to be race-free with
other lock_sock() callers, for example, tipc_release(). Otherwise
using the spinlock directly can't serialize a parallel tipc_release().
As it is blocking, we have to hold the sock refcnt before
rhashtable_walk_stop() and release it after rhashtable_walk_start().
Fixes: 07f6c4bc04 ("tipc: convert tipc reference table to use generic rhashtable")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We see the following lockdep warning:
[ 2284.078521] ======================================================
[ 2284.078604] WARNING: possible circular locking dependency detected
[ 2284.078604] 4.19.0+ #42 Tainted: G E
[ 2284.078604] ------------------------------------------------------
[ 2284.078604] rmmod/254 is trying to acquire lock:
[ 2284.078604] 00000000acd94e28 ((&n->timer)#2){+.-.}, at: del_timer_sync+0x5/0xa0
[ 2284.078604]
[ 2284.078604] but task is already holding lock:
[ 2284.078604] 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x190 [tipc]
[ 2284.078604]
[ 2284.078604] which lock already depends on the new lock.
[ 2284.078604]
[ 2284.078604]
[ 2284.078604] the existing dependency chain (in reverse order) is:
[ 2284.078604]
[ 2284.078604] -> #1 (&(&tn->node_list_lock)->rlock){+.-.}:
[ 2284.078604] tipc_node_timeout+0x20a/0x330 [tipc]
[ 2284.078604] call_timer_fn+0xa1/0x280
[ 2284.078604] run_timer_softirq+0x1f2/0x4d0
[ 2284.078604] __do_softirq+0xfc/0x413
[ 2284.078604] irq_exit+0xb5/0xc0
[ 2284.078604] smp_apic_timer_interrupt+0xac/0x210
[ 2284.078604] apic_timer_interrupt+0xf/0x20
[ 2284.078604] default_idle+0x1c/0x140
[ 2284.078604] do_idle+0x1bc/0x280
[ 2284.078604] cpu_startup_entry+0x19/0x20
[ 2284.078604] start_secondary+0x187/0x1c0
[ 2284.078604] secondary_startup_64+0xa4/0xb0
[ 2284.078604]
[ 2284.078604] -> #0 ((&n->timer)#2){+.-.}:
[ 2284.078604] del_timer_sync+0x34/0xa0
[ 2284.078604] tipc_node_delete+0x1a/0x40 [tipc]
[ 2284.078604] tipc_node_stop+0xcb/0x190 [tipc]
[ 2284.078604] tipc_net_stop+0x154/0x170 [tipc]
[ 2284.078604] tipc_exit_net+0x16/0x30 [tipc]
[ 2284.078604] ops_exit_list.isra.8+0x36/0x70
[ 2284.078604] unregister_pernet_operations+0x87/0xd0
[ 2284.078604] unregister_pernet_subsys+0x1d/0x30
[ 2284.078604] tipc_exit+0x11/0x6f2 [tipc]
[ 2284.078604] __x64_sys_delete_module+0x1df/0x240
[ 2284.078604] do_syscall_64+0x66/0x460
[ 2284.078604] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 2284.078604]
[ 2284.078604] other info that might help us debug this:
[ 2284.078604]
[ 2284.078604] Possible unsafe locking scenario:
[ 2284.078604]
[ 2284.078604] CPU0 CPU1
[ 2284.078604] ---- ----
[ 2284.078604] lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604] lock((&n->timer)#2);
[ 2284.078604] lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604] lock((&n->timer)#2);
[ 2284.078604]
[ 2284.078604] *** DEADLOCK ***
[ 2284.078604]
[ 2284.078604] 3 locks held by rmmod/254:
[ 2284.078604] #0: 000000003368be9b (pernet_ops_rwsem){+.+.}, at: unregister_pernet_subsys+0x15/0x30
[ 2284.078604] #1: 0000000046ed9c86 (rtnl_mutex){+.+.}, at: tipc_net_stop+0x144/0x170 [tipc]
[ 2284.078604] #2: 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x19
[...}
The reason is that the node timer handler sometimes needs to delete a
node which has been disconnected for too long. To do this, it grabs
the lock 'node_list_lock', which may at the same time be held by the
generic node cleanup function, tipc_node_stop(), during module removal.
Since the latter is calling del_timer_sync() inside the same lock, we
have a potential deadlock.
We fix this letting the timer cleanup function use spin_trylock()
instead of just spin_lock(), and when it fails to grab the lock it
just returns so that the timer handler can terminate its execution.
This is safe to do, since tipc_node_stop() anyway is about to
delete both the timer and the node instance.
Fixes: 6a939f365b ("tipc: Auto removal of peer down node instance")
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code for reading ancillary data from a received buffer is assuming
the buffer is linear. To make this assumption true we have to linearize
the buffer before message data is read.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a link failure is detected locally, the link is reset, the flag
link->in_session is set to false, and a RESET_MSG with the 'stopping'
bit set is sent to the peer.
The purpose of this bit is to inform the peer that this endpoint just
is going down, and that the peer should handle the reception of this
particular RESET message as a local failure. This forces the peer to
accept another RESET or ACTIVATE message from this endpoint before it
can re-establish the link. This again is necessary to ensure that
link session numbers are properly exchanged before the link comes up
again.
If a failure is detected locally at the same time at the peer endpoint
this will do the same, which is also a correct behavior.
However, when receiving such messages, the endpoints will not
distinguish between 'stopping' RESETs and ordinary ones when it comes
to updating session numbers. Both endpoints will copy the received
session number and set their 'in_session' flags to true at the
reception, while they are still expecting another RESET from the
peer before they can go ahead and re-establish. This is contradictory,
since, after applying the validation check referred to below, the
'in_session' flag will cause rejection of all such messages, and the
link will never come up again.
We now fix this by not only handling received RESET/STOPPING messages
as a local failure, but also by omitting to set a new session number
and the 'in_session' flag in such cases.
Fixes: 7ea817f4e8 ("tipc: check session number before accepting link protocol messages")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull AFS updates from Al Viro:
"AFS series, with some iov_iter bits included"
* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
missing bits of "iov_iter: Separate type from direction and use accessor functions"
afs: Probe multiple fileservers simultaneously
afs: Fix callback handling
afs: Eliminate the address pointer from the address list cursor
afs: Allow dumping of server cursor on operation failure
afs: Implement YFS support in the fs client
afs: Expand data structure fields to support YFS
afs: Get the target vnode in afs_rmdir() and get a callback on it
afs: Calc callback expiry in op reply delivery
afs: Fix FS.FetchStatus delivery from updating wrong vnode
afs: Implement the YFS cache manager service
afs: Remove callback details from afs_callback_break struct
afs: Commit the status on a new file/dir/symlink
afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
afs: Don't invoke the server to read data beyond EOF
afs: Add a couple of tracepoints to log I/O errors
afs: Handle EIO from delivery function
afs: Fix TTL on VL server and address lists
afs: Implement VL server rotation
afs: Improve FS server rotation error handling
...
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
This reverts commit dd979b4df8.
This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an
internal TCP socket for the initial handshake with the remote peer.
Whenever the SMC connection can not be established this TCP socket is
used as a fallback. All socket operations on the SMC socket are then
forwarded to the TCP socket. In case of poll, the file->private_data
pointer references the SMC socket because the TCP socket has no file
assigned. This causes tcp_poll to wait on the wrong socket.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have seen the following race scenario:
1) named_distribute() builds a "bulk" message, containing a PUBLISH
item for a certain publication. This is based on the contents of
the binding tables's 'cluster_scope' list.
2) tipc_named_withdraw() removes the same publication from the list,
bulds a WITHDRAW message and distributes it to all cluster nodes.
3) tipc_named_node_up(), which was calling named_distribute(), sends
out the bulk message built under 1)
4) The WITHDRAW message arrives at the just detected node, finds
no corresponding publication, and is dropped.
5) The PUBLISH item arrives at the same node, is added to its binding
table, and remains there forever.
This arrival disordering was earlier taken care of by the backlog queue,
originally added for a different purpose, which was removed in the
commit referred to below, but we now need a different solution.
In this commit, we replace the rcu lock protecting the 'cluster_scope'
list with a regular RW lock which comprises even the sending of the
bulk message. This both guarantees both the list integrity and the
message sending order. We will later add a commit which cleans up
this code further.
Note that this commit needs recently added commit d3092b2efc ("tipc:
fix unsafe rcu locking when accessing publication list") to apply
cleanly.
Fixes: 37922ea4a3 ("tipc: permit overlapping service ranges in name table")
Reported-by: Tuong Lien Tong <tuong.t.lien@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Got below warning with gcc 8.2 compiler.
net/tipc/topsrv.c: In function ‘tipc_topsrv_start’:
net/tipc/topsrv.c:660:2: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=]
strncpy(srv->name, name, strlen(name) + 1);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/topsrv.c:660:27: note: length computed here
strncpy(srv->name, name, strlen(name) + 1);
^~~~~~~~~~~~
So change it to correct length and use strscpy.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sched/cls_api.c has overlapping changes to a call to
nlmsg_parse(), one (from 'net') added rtm_tca_policy instead of NULL
to the 5th argument, and another (from 'net-next') added cb->extack
instead of NULL to the 6th argument.
net/ipv4/ipmr_base.c is a case of a bug fix in 'net' being done to
code which moved (to mr_table_dump)) in 'net-next'. Thanks to David
Ahern for the heads up.
Signed-off-by: David S. Miller <davem@davemloft.net>
The binding table's 'cluster_scope' list is rcu protected to handle
races between threads changing the list and those traversing the list at
the same moment. We have now found that the function named_distribute()
uses the regular list_for_each() macro to traverse the said list.
Likewise, the function tipc_named_withdraw() is removing items from the
same list using the regular list_del() call. When these two functions
execute in parallel we see occasional crashes.
This commit fixes this by adding the missing _rcu() suffixes.
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the commit referred to below we added link tolerance as an additional
criteria for declaring broadcast transmission "stale" and resetting the
unicast links to the affected node.
Unfortunately, this 'improvement' introduced two bugs, which each and
one alone cause only limited problems, but combined lead to seemingly
stochastic unicast link resets, depending on the amount of broadcast
traffic transmitted.
The first issue, a missing initialization of the 'tolerance' field of
the receiver broadcast link, was recently fixed by commit 047491ea33
("tipc: set link tolerance correctly in broadcast link").
Ths second issue, where we omit to reset the 'stale_cnt' field of
the same link after a 'stale' period is over, leads to this counter
accumulating over time, and in the absence of the 'tolerance' criteria
leads to the above described symptoms. This commit adds the missing
initialization.
Fixes: a4dc70d46c ("tipc: extend link reset criteria for stale packet retransmission")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
INADDR_ANY is hard-coded when activating UDP bearer. So, we could not
bind to a specific IP address even with replicast mode using - given
remote ip address instead of using multicast ip address.
In this commit, we fixed it by checking and switch to use appropriate
local ip address.
before:
$netstat -plu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address
udp 0 0 **0.0.0.0:6118** 0.0.0.0:*
after:
$netstat -plu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address
udp 0 0 **10.0.0.2:6118** 0.0.0.0:*
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <davem@davemloft.net>
When booting kernel with LOCKDEP option, below warning info was found:
WARNING: possible recursive locking detected
4.19.0-rc7+ #14 Not tainted
--------------------------------------------
swapper/0/1 is trying to acquire lock:
00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh
include/linux/spinlock.h:334 [inline]
00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at:
tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850
but task is already holding lock:
00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh
include/linux/spinlock.h:334 [inline]
00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at:
tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&list->lock)->rlock#4);
lock(&(&list->lock)->rlock#4);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by swapper/0/1:
#0: 00000000f7539d34 (pernet_ops_rwsem){+.+.}, at:
register_pernet_subsys+0x19/0x40 net/core/net_namespace.c:1051
#1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at:
spin_lock_bh include/linux/spinlock.h:334 [inline]
#1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at:
tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849
stack backtrace:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7+ #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1af/0x295 lib/dump_stack.c:113
print_deadlock_bug kernel/locking/lockdep.c:1759 [inline]
check_deadlock kernel/locking/lockdep.c:1803 [inline]
validate_chain kernel/locking/lockdep.c:2399 [inline]
__lock_acquire+0xf1e/0x3c60 kernel/locking/lockdep.c:3411
lock_acquire+0x1db/0x520 kernel/locking/lockdep.c:3900
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850
tipc_link_bc_create+0xb5/0x1f0 net/tipc/link.c:526
tipc_bcast_init+0x59b/0xab0 net/tipc/bcast.c:521
tipc_init_net+0x472/0x610 net/tipc/core.c:82
ops_init+0xf7/0x520 net/core/net_namespace.c:129
__register_pernet_operations net/core/net_namespace.c:940 [inline]
register_pernet_operations+0x453/0xac0 net/core/net_namespace.c:1011
register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1052
tipc_init+0x83/0x104 net/tipc/core.c:140
do_one_initcall+0x109/0x70a init/main.c:885
do_initcall_level init/main.c:953 [inline]
do_initcalls init/main.c:961 [inline]
do_basic_setup init/main.c:979 [inline]
kernel_init_freeable+0x4bd/0x57f init/main.c:1144
kernel_init+0x13/0x180 init/main.c:1063
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
The reason why the noise above was complained by LOCKDEP is because we
nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset
function. In fact it's unnecessary to move skb buffer from l->wakeupq
queue to l->inputq queue while holding the two locks at the same time.
Instead, we can move skb buffers in l->wakeupq queue to a temporary
list first and then move the buffers of the temporary list to l->inputq
queue, which is also safe for us.
Fixes: 3f32d0be6c ("tipc: lock wakeup & inputq at tipc_link_reset()")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In tipc_sk_filter_rcv(), when we detect protocol messages with error we
call tipc_sk_conn_proto_rcv() and let it reset the connection and notify
the socket by calling sk->sk_state_change().
However, tipc_sk_filter_rcv() may have been called from the function
tipc_backlog_rcv(), in which case the socket lock is held and the socket
already awake. This means that the sk_state_change() call is ignored and
the error notification lost. Now the receive queue will remain empty and
the socket sleeps forever.
In this commit, we convert the protocol message into a connection abort
message and enqueue it into the socket's receive queue. By this addition
to the above state change we cover all conditions.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the patch referred to below we added link tolerance as an additional
criteria for declaring broadcast transmission "stale" and resetting the
affected links.
However, the 'tolerance' field of the broadcast link is never set, and
remains at zero. This renders the whole commit without the intended
improving effect, but luckily also with no negative effect.
In this commit we add the missing initialization.
Fixes: a4dc70d46c ("tipc: extend link reset criteria for stale packet retransmission")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor conflict in net/core/rtnetlink.c, David Ahern's bug fix in 'net'
overlapped the renaming of a netlink attribute in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
The initial session number when a link is created is based on a random
value, taken from struct tipc_net->random. It is then incremented for
each link reset to avoid mixing protocol messages from different link
sessions.
However, when a bearer is reset all its links are deleted, and will
later be re-created using the same random value as the first time.
This means that if the link never went down between creation and
deletion we will still sometimes have two subsequent sessions with
the same session number. In virtual environments with potentially
long transmission times this has turned out to be a real problem.
We now fix this by randomizing the session number each time a link
is created.
With a session number size of 16 bits this gives a risk of session
collision of 1/64k. To reduce this further, we also introduce a sanity
check on the very first STATE message arriving at a link. If this has
an acknowledge value differing from 0, which is logically impossible,
we ignore the message. The final risk for session collision is hence
reduced to 1/4G, which should be sufficient.
Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We see the following scenario:
1) Link endpoint B on node 1 discovers that its peer endpoint is gone.
Since there is a second working link, failover procedure is started.
2) Link endpoint A on node 1 sends a FAILOVER message to peer endpoint
A on node 2. The node item 1->2 goes to state FAILINGOVER.
3) Linke endpoint A/2 receives the failover, and is supposed to take
down its parallell link endpoint B/2, while producing a FAILOVER
message to send back to A/1.
4) However, B/2 has already been deleted, so no FAILOVER message can
created.
5) Node 1->2 remains in state FAILINGOVER forever, refusing to receive
any messages that can bring B/1 up again. We are left with a non-
redundant link between node 1 and 2.
We fix this with letting endpoint A/2 build a dummy FAILOVER message
to send to back to A/1, so that the situation can be resolved.
Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Default socket receive buffer size for a listener socket is 2Mb. For
each arriving empty SYN, the linux kernel allocates a 768 bytes buffer.
This means that a listener socket can serve maximum 2700 simultaneous
empty connection setup requests before it hits a receive buffer
overflow, and much fewer if the SYN is carrying any significant
amount of data.
When this happens the setup request is rejected, and the client
receives an ECONNREFUSED error.
This commit mitigates this problem by letting the client socket try to
retransmit the SYN message multiple times when it sees it rejected with
the code TIPC_ERR_OVERLOAD. Retransmission is done at random intervals
in the range of [100 ms, setup_timeout / 4], as many times as there is
room for within the setup timeout limit.
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Messages intended for intitating a connection are currently
indistinguishable from regular datagram messages. The TIPC
protocol specification defines bit 17 in word 0 as a SYN bit
to allow sanity check of such messages in the listening socket,
but this has so far never been implemented.
We do that in this commit.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We refactor the function tipc_sk_filter_connect(), both to make it
more readable and as a preparation for the next commit.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function tipc_msg_reverse() is reversing the header of a message
while reusing the original buffer. We have seen at several occasions
that this may have unfortunate side effects when the buffer to be
reversed is a clone.
In one of the following commits we will again need to reverse cloned
buffers, so this is the right time to permanently eliminate this
problem. In this commit we let the said function always consume the
original buffer and replace it with a new one when applicable.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In tipc_link_reset() we copy the wakeup queue to input queue using
skb_queue_splice_init(link->wakeupq, link->inputq).
This is performed without holding any locks. The lists might be
simultaneously be accessed by other cpu threads in tipc_sk_rcv(),
something leading to to random missing packets.
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the case of implicit connect message with data > 1K, the flow
control accounting is incorrect. At this state, the socket does not
know the peer nodes capability and falls back to legacy flow control
by return 1, however the receiver of this message will perform the
new block accounting. This leads to a slack and eventually traffic
disturbance.
In this commit, we perform tipc_node_get_capabilities() at implicit
connect and perform accounting based on the peer's capability.
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An SKB is not on a list if skb->next is NULL.
Codify this convention into a helper function and use it
where we are dequeueing an SKB and need to mark it as such.
Signed-off-by: David S. Miller <davem@davemloft.net>
__tipc_nl_compat_dumpit() uses a netlink_callback on stack,
so the only way to align it with other ->dumpit() call path
is calling tipc_dump_start() and tipc_dump_done() directly
inside it. Otherwise ->dumpit() would always get NULL from
cb->args[].
But tipc_dump_start() uses sock_net(cb->skb->sk) to retrieve
net pointer, the cb->skb here doesn't set skb->sk, the net pointer
is saved in msg->net instead, so introduce a helper function
__tipc_dump_start() to pass in msg->net.
Ying pointed out cb->args[0...3] are already used by other
callbacks on this call path, so we can't use cb->args[0] any
more, use cb->args[4] instead.
Fixes: 9a07efa9ae ("tipc: switch to rhashtable iterator")
Reported-and-tested-by: syzbot+e93a2c41f91b8e2c7d9b@syzkaller.appspotmail.com
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
