This is a note to let you know that I've just added the patch titled
sctp: handle association restarts when the socket is closed.
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sctp-handle-association-restarts-when-the-socket-is-closed.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Sun Oct 12 20:11:55 CEST 2014
From: Vlad Yasevich <vyasevich@xxxxxxxxx>
Date: Fri, 3 Oct 2014 18:16:20 -0400
Subject: sctp: handle association restarts when the socket is closed.
From: Vlad Yasevich <vyasevich@xxxxxxxxx>
[ Upstream commit bdf6fa52f01b941d4a80372d56de465bdbbd1d23 ]
Currently association restarts do not take into consideration the
state of the socket. When a restart happens, the current assocation
simply transitions into established state. This creates a condition
where a remote system, through a the restart procedure, may create a
local association that is no way reachable by user. The conditions
to trigger this are as follows:
1) Remote does not acknoledge some data causing data to remain
outstanding.
2) Local application calls close() on the socket. Since data
is still outstanding, the association is placed in SHUTDOWN_PENDING
state. However, the socket is closed.
3) The remote tries to create a new association, triggering a restart
on the local system. The association moves from SHUTDOWN_PENDING
to ESTABLISHED. At this point, it is no longer reachable by
any socket on the local system.
This patch addresses the above situation by moving the newly ESTABLISHED
association into SHUTDOWN-SENT state and bundling a SHUTDOWN after
the COOKIE-ACK chunk. This way, the restarted associate immidiately
enters the shutdown procedure and forces the termination of the
unreachable association.
Reported-by: David Laight <David.Laight@xxxxxxxxxx>
Signed-off-by: Vlad Yasevich <vyasevich@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/sctp/command.h | 2 +-
net/sctp/sm_statefuns.c | 19 ++++++++++++++++---
2 files changed, 17 insertions(+), 4 deletions(-)
--- a/include/net/sctp/command.h
+++ b/include/net/sctp/command.h
@@ -115,7 +115,7 @@ typedef enum {
* analysis of the state functions, but in reality just taken from
* thin air in the hopes othat we don't trigger a kernel panic.
*/
-#define SCTP_MAX_NUM_COMMANDS 14
+#define SCTP_MAX_NUM_COMMANDS 20
typedef union {
__s32 i32;
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -1775,9 +1775,22 @@ static sctp_disposition_t sctp_sf_do_dup
/* Update the content of current association. */
sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
- sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
- SCTP_STATE(SCTP_STATE_ESTABLISHED));
- sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ if (sctp_state(asoc, SHUTDOWN_PENDING) &&
+ (sctp_sstate(asoc->base.sk, CLOSING) ||
+ sock_flag(asoc->base.sk, SOCK_DEAD))) {
+ /* if were currently in SHUTDOWN_PENDING, but the socket
+ * has been closed by user, don't transition to ESTABLISHED.
+ * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
+ SCTP_ST_CHUNK(0), NULL,
+ commands);
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ }
return SCTP_DISPOSITION_CONSUME;
nomem_ev:
Patches currently in stable-queue which might be from vyasevich@xxxxxxxxx are
queue-3.16/ipv6-remove-rt6i_genid.patch
queue-3.16/macvtap-fix-race-between-device-delete-and-open.patch
queue-3.16/bridge-fix-br_should_learn-to-check-vlan_enabled.patch
queue-3.16/tg3-work-around-hw-fw-limitations-with-vlan-encapsulated-frames.patch
queue-3.16/bridge-check-if-vlan-filtering-is-enabled-only-once.patch
queue-3.16/tg3-allow-for-recieve-of-full-size-8021ad-frames.patch
queue-3.16/sctp-handle-association-restarts-when-the-socket-is-closed.patch
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