linux.git/net/x25, branch v5.11

net: x25: Remove unimplemented X.25-over-LLC code stubs

2020-12-13T01:15:33+00:00

According to the X.25 documentation, there was a plan to implement
X.25-over-802.2-LLC. It never finished but left various code stubs in the
X.25 code. At this time it is unlikely that it would ever finish so it
may be better to remove those code stubs.

Also change the documentation to make it clear that this is not a ongoing
plan anymore. Change words like "will" to "could", "would", etc.

Cc: Martin Schiller 
Signed-off-by: Xie He 
Link: https://lore.kernel.org/r/20201209033346.83742-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski

net: x25: Fix handling of Restart Request and Restart Confirmation

2020-12-10T03:34:25+00:00

1. When the x25 module gets loaded, layer 2 may already be running and
connected. In this case, although we are in X25_LINK_STATE_0, we still
need to handle the Restart Request received, rather than ignore it.

2. When we are in X25_LINK_STATE_2, we have already sent a Restart Request
and is waiting for the Restart Confirmation with t20timer. t20timer will
restart itself repeatedly forever so it will always be there, as long as we
are in State 2. So we don't need to check x25_t20timer_pending again.

Fixes: d023b2b9ccc2 ("net/x25: fix restart request/confirm handling")
Cc: Martin Schiller 
Signed-off-by: Xie He 
Acked-by: Martin Schiller 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-12-03T23:44:09+00:00

Conflicts:
	drivers/net/ethernet/ibm/ibmvnic.c

Signed-off-by: Jakub Kicinski

net/x25: prevent a couple of overflows

2020-12-03T01:26:36+00:00

The .x25_addr[] address comes from the user and is not necessarily
NUL terminated.  This leads to a couple problems.  The first problem is
that the strlen() in x25_bind() can read beyond the end of the buffer.

The second problem is more subtle and could result in memory corruption.
The call tree is:
  x25_connect()
  --> x25_write_internal()
      --> x25_addr_aton()

The .x25_addr[] buffers are copied to the "addresses" buffer from
x25_write_internal() so it will lead to stack corruption.

Verify that the strings are NUL terminated and return -EINVAL if they
are not.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: a9288525d2ae ("X25: Dont let x25_bind use addresses containing characters")
Reported-by: "kiyin(尹亮)" 
Signed-off-by: Dan Carpenter 
Acked-by: Martin Schiller 
Link: https://lore.kernel.org/r/X8ZeAKm8FnFpN//B@mwanda
Signed-off-by: Jakub Kicinski

net/x25: remove x25_kill_by_device()

2020-11-28T01:22:51+00:00

Remove obsolete function x25_kill_by_device(). It's not used any more.

Signed-off-by: Martin Schiller 
Signed-off-by: Jakub Kicinski

net/x25: fix restart request/confirm handling

2020-11-28T01:22:51+00:00

We have to take the actual link state into account to handle
restart requests/confirms well.

Signed-off-by: Martin Schiller 
Signed-off-by: Jakub Kicinski

net/x25: handle additional netdev events

2020-11-28T01:22:51+00:00

1. Add / remove x25_link_device by NETDEV_REGISTER/UNREGISTER and also
   by NETDEV_POST_TYPE_CHANGE/NETDEV_PRE_TYPE_CHANGE.

   This change is needed so that the x25_neigh struct for an interface
   is already created when it shows up and is kept independently if the
   interface goes UP or DOWN.

   This is used in an upcomming commit, where x25 params of an neighbour
   will get configurable through ioctls.

2. NETDEV_CHANGE event makes it possible to handle carrier loss and
   detection. If carrier is lost, clean up everything related to this
   neighbour by calling x25_link_terminated().

3. Also call x25_link_terminated() for NETDEV_DOWN events and remove the
   call to x25_clear_forward_by_dev() in x25_route_device_down(), as
   this is already called by x25_kill_by_neigh() which gets called by
   x25_link_terminated().

4. Do nothing for NETDEV_UP and NETDEV_GOING_DOWN events, as these will
   be handled in layer 2 (LAPB) and layer3 (X.25) will be informed by
   layer2 when layer2 link is established and layer3 link should be
   initiated.

Signed-off-by: Martin Schiller 
Signed-off-by: Jakub Kicinski

net: x25: Increase refcnt of "struct x25_neigh" in x25_rx_call_request

2020-11-13T02:01:40+00:00

The x25_disconnect function in x25_subr.c would decrease the refcount of
"x25->neighbour" (struct x25_neigh) and reset this pointer to NULL.

However, the x25_rx_call_request function in af_x25.c, which is called
when we receive a connection request, does not increase the refcount when
it assigns the pointer.

Fix this issue by increasing the refcount of "struct x25_neigh" in
x25_rx_call_request.

This patch fixes frequent kernel crashes when using AF_X25 sockets.

Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect")
Cc: Martin Schiller 
Signed-off-by: Xie He 
Link: https://lore.kernel.org/r/20201112103506.5875-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski

net/x25: Fix null-ptr-deref in x25_connect

2020-11-11T22:53:56+00:00

This fixes a regression for blocking connects introduced by commit
4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect").

The x25->neighbour is already set to "NULL" by x25_disconnect() now,
while a blocking connect is waiting in
x25_wait_for_connection_establishment(). Therefore x25->neighbour must
not be accessed here again and x25->state is also already set to
X25_STATE_0 by x25_disconnect().

Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect")
Signed-off-by: Martin Schiller 
Reviewed-by: Xie He 
Link: https://lore.kernel.org/r/20201109065449.9014-1-ms@dev.tdt.de
Signed-off-by: Jakub Kicinski

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva