linux-stable.git/net/tipc/name_table.c, branch linux-4.17.y

tipc: fix use-after-free in tipc_nametbl_stop

2018-04-18T17:48:43+00:00

When we delete a service item in tipc_nametbl_stop() we loop over
all service ranges in the service's RB tree, and for each service
range we loop over its pertaining publications while calling
tipc_service_remove_publ() for each of them.

However, tipc_service_remove_publ() has the side effect that it also
removes the comprising service range item when there are no publications
left. This leads to a "use-after-free" access when the inner loop
continues to the next iteration, since the range item holding the list
we are looping no longer exists.

We fix this by moving the delete of the service range item outside
the said function. Instead, we now let the two functions calling it
test if the list is empty and perform the removal when that is the
case.

Reported-by: syzbot+d64b64afc55660106556@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: fix unbalanced reference counter

2018-04-13T01:46:10+00:00

When a topology subscription is created, we may encounter (or KASAN
may provoke) a failure to create a corresponding service instance in
the binding table. Instead of letting the tipc_nametbl_subscribe()
report the failure back to the caller, the function just makes a warning
printout and returns, without incrementing the subscription reference
counter as expected by the caller.

This makes the caller believe that the subscription was successful, so
it will at a later moment try to unsubscribe the item. This involves
a sub_put() call. Since the reference counter never was incremented
in the first place, we get a premature delete of the subscription item,
followed by a "use-after-free" warning.

We fix this by adding a return value to tipc_nametbl_subscribe() and
make the caller aware of the failure to subscribe.

This bug seems to always have been around, but this fix only applies
back to the commit shown below. Given the low risk of this happening
we believe this to be sufficient.

Fixes: commit 218527fe27ad ("tipc: replace name table service range
array with rb tree")
Reported-by: syzbot+aa245f26d42b8305d157@syzkaller.appspotmail.com

Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: permit overlapping service ranges in name table

2018-04-01T02:19:52+00:00

With the new RB tree structure for service ranges it becomes possible to
solve an old problem; - we can now allow overlapping service ranges in
the table.

When inserting a new service range to the tree, we use 'lower' as primary
key, and when necessary 'upper' as secondary key.

Since there may now be multiple service ranges matching an indicated
'lower' value, we must also add the 'upper' value to the functions
used for removing publications, so that the correct, corresponding
range item can be found.

These changes guarantee that a well-formed publication/withdrawal item
from a peer node never will be rejected, and make it possible to
eliminate the problematic backlog functionality we currently have for
handling such cases.

Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: refactor name table translate function

2018-04-01T02:19:52+00:00

The function tipc_nametbl_translate() function is ugly and hard to
follow. This can be improved somewhat by introducing a stack variable
for holding the publication list to be used and re-ordering the if-
clauses for selection of algorithm.

Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: replace name table service range array with rb tree

2018-04-01T02:19:52+00:00

The current design of the binding table has an unnecessary memory
consuming and complex data structure. It aggregates the service range
items into an array, which is expanded by a factor two every time it
becomes too small to hold a new item. Furthermore, the arrays never
shrink when the number of ranges diminishes.

We now replace this array with an RB tree that is holding the range
items as tree nodes, each range directly holding a list of bindings.

This, along with a few name changes, improves both readability and
volume of the code, as well as reducing memory consumption and hopefully
improving cache hit rate.

Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: remove direct accesses to own_addr field in struct tipc_net

2018-03-23T17:12:18+00:00

As a preparation to changing the addressing structure of TIPC we replace
all direct accesses to the tipc_net::own_addr field with the function
dedicated for this, tipc_own_addr().

There are no changes to program logics in this commit.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: allow closest-first lookup algorithm when legacy address is configured

2018-03-23T17:12:18+00:00

The removal of an internal structure of the node address has an unwanted
side effect.
- Currently, if a user is sending an anycast message with destination
  domain 0, the tipc_namebl_translate() function will use the 'closest-
  first' algorithm to first look for a node local destination, and only
  when no such is found, will it resort to the cluster global 'round-
  robin' lookup algorithm.
- Current users can get around this, and enforce unconditional use of
  global round-robin by indicating a destination as Z.0.0 or Z.C.0.
- This option disappears when we make the node address flat, since the
  lookup algorithm has no way of recognizing this case. So, as long as
  there are node local destinations, the algorithm will always select
  one of those, and there is nothing the sender can do to change this.

We solve this by eliminating the 'closest-first' option, which was never
a good idea anyway, for non-legacy users, but only for those. To
distinguish between legacy users and non-legacy users we introduce a new
flag 'legacy_addr_format' in struct tipc_core, to be set when the user
configures a legacy-style Z.C.N node address. Hence, when a legacy user
indicates a zero lookup domain 'closest-first' is selected, and in all
other cases we use 'round-robin'.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: some name changes

2018-03-17T21:11:46+00:00

We rename some lists and fields in struct publication both to make
the naming more consistent and to better reflect their roles. We
also update the descriptions of those lists.

node_list -> local_publ
cluster_list -> all_publ
pport_list -> binding_sock
ref -> port

There are no functional changes in this commit.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: remove zone_list member in struct publication

2018-03-17T21:11:46+00:00

As a further consequence of the previous commits, we can also remove
the member 'zone_list 'in struct name_info and struct publication.
Instead, we now let the member cluster_list take over the role a
container of all publications of a given .
We also remove the counters for the size of those lists, since
they don't serve any purpose.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: remove zone publication list in name table

2018-03-17T21:11:46+00:00

As a consequence of the previous commit we nan now eliminate zone scope
related lists in the name table. We start with name_table::publ_list[3],
which can now be replaced with two lists, one for node scope publications
and one for cluster scope publications.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller