kernel/linux.git/net/rds/tcp.c, branch linux-4.4.y

RDS:TCP: Synchronize rds_tcp_accept_one with rds_send_xmit when resetting t_sock

2020-05-10T08:26:01+00:00

commit eb192840266fab3e3da644018121eed30153355d upstream. There is a race condition between rds_send_xmit -> rds_tcp_xmit and the code that deals with resolution of duelling syns added by commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an outgoing socket in rds_tcp_accept_one()"). Specifically, we may end up derefencing a null pointer in rds_send_xmit if we have the interleaving sequence: rds_tcp_accept_one rds_send_xmit conn is RDS_CONN_UP, so invoke rds_tcp_xmit tc = conn->c_transport_data rds_tcp_restore_callbacks /* reset t_sock */ null ptr deref from tc->t_sock The race condition can be avoided without adding the overhead of additional locking in the xmit path: have rds_tcp_accept_one wait for rds_tcp_xmit threads to complete before resetting callbacks. The synchronization can be done in the same manner as rds_conn_shutdown(). First set the rds_conn_state to something other than RDS_CONN_UP (so that new threads cannot get into rds_tcp_xmit()), then wait for RDS_IN_XMIT to be cleared in the conn->c_flags indicating that any threads in rds_tcp_xmit are done. Fixes: 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an outgoing socket in rds_tcp_accept_one()") Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: rds: Fix NULL ptr use in rds_tcp_kill_sock

2019-10-05T10:27:38+00:00

After the commit c4e97b06cfdc ("net: rds: force to destroy connection if t_sock is NULL in rds_tcp_kill_sock()."), it introduced null-ptr-deref in rds_tcp_kill_sock as below: BUG: KASAN: null-ptr-deref on address 0000000000000020 Read of size 8 by task kworker/u16:10/910 CPU: 3 PID: 910 Comm: kworker/u16:10 Not tainted 4.4.178+ #3 Hardware name: linux,dummy-virt (DT) Workqueue: netns cleanup_net Call trace: [] dump_backtrace+0x0/0x618 [] show_stack+0x38/0x60 [] dump_stack+0x1a8/0x230 [] kasan_report_error+0xc8c/0xfc0 [] kasan_report+0x94/0xd8 [] __asan_load8+0x88/0x150 [] rds_tcp_dev_event+0x734/0xb48 [] raw_notifier_call_chain+0x150/0x1e8 [] call_netdevice_notifiers_info+0x90/0x110 [] netdev_run_todo+0x2f4/0xb08 [] rtnl_unlock+0x2c/0x48 [] default_device_exit_batch+0x444/0x528 [] ops_exit_list+0x1c0/0x240 [] cleanup_net+0x738/0xbf8 [] process_one_work+0x96c/0x13e0 [] worker_thread+0x7e0/0x1910 [] kthread+0x304/0x390 [] ret_from_fork+0x10/0x50 If the first loop add the tc->t_sock = NULL to the tmp_list, 1). list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) then the second loop is to find connections to destroy, tc->t_sock might equal NULL, and tc->t_sock->sk happens null-ptr-deref. 2). list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) Fixes: c4e97b06cfdc ("net: rds: force to destroy connection if t_sock is NULL in rds_tcp_kill_sock().") Signed-off-by: Mao Wenan Signed-off-by: Greg Kroah-Hartman

net: rds: force to destroy connection if t_sock is NULL in rds_tcp_kill_sock().

2019-04-27T07:33:54+00:00

[ Upstream commit cb66ddd156203daefb8d71158036b27b0e2caf63 ] When it is to cleanup net namespace, rds_tcp_exit_net() will call rds_tcp_kill_sock(), if t_sock is NULL, it will not call rds_conn_destroy(), rds_conn_path_destroy() and rds_tcp_conn_free() to free connection, and the worker cp_conn_w is not stopped, afterwards the net is freed in net_drop_ns(); While cp_conn_w rds_connect_worker() will call rds_tcp_conn_path_connect() and reference 'net' which has already been freed. In rds_tcp_conn_path_connect(), rds_tcp_set_callbacks() will set t_sock = sock before sock->ops->connect, but if connect() is failed, it will call rds_tcp_restore_callbacks() and set t_sock = NULL, if connect is always failed, rds_connect_worker() will try to reconnect all the time, so rds_tcp_kill_sock() will never to cancel worker cp_conn_w and free the connections. Therefore, the condition !tc->t_sock is not needed if it is going to do cleanup_net->rds_tcp_exit_net->rds_tcp_kill_sock, because tc->t_sock is always NULL, and there is on other path to cancel cp_conn_w and free connection. So this patch is to fix this. rds_tcp_kill_sock(): ... if (net != c_net || !tc->t_sock) ... Acked-by: Santosh Shilimkar ================================================================== BUG: KASAN: use-after-free in inet_create+0xbcc/0xd28 net/ipv4/af_inet.c:340 Read of size 4 at addr ffff8003496a4684 by task kworker/u8:4/3721 CPU: 3 PID: 3721 Comm: kworker/u8:4 Not tainted 5.1.0 #11 Hardware name: linux,dummy-virt (DT) Workqueue: krdsd rds_connect_worker Call trace: dump_backtrace+0x0/0x3c0 arch/arm64/kernel/time.c:53 show_stack+0x28/0x38 arch/arm64/kernel/traps.c:152 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x120/0x188 lib/dump_stack.c:113 print_address_description+0x68/0x278 mm/kasan/report.c:253 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x21c/0x348 mm/kasan/report.c:409 __asan_report_load4_noabort+0x30/0x40 mm/kasan/report.c:429 inet_create+0xbcc/0xd28 net/ipv4/af_inet.c:340 __sock_create+0x4f8/0x770 net/socket.c:1276 sock_create_kern+0x50/0x68 net/socket.c:1322 rds_tcp_conn_path_connect+0x2b4/0x690 net/rds/tcp_connect.c:114 rds_connect_worker+0x108/0x1d0 net/rds/threads.c:175 process_one_work+0x6e8/0x1700 kernel/workqueue.c:2153 worker_thread+0x3b0/0xdd0 kernel/workqueue.c:2296 kthread+0x2f0/0x378 kernel/kthread.c:255 ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:1117 Allocated by task 687: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xd4/0x180 mm/kasan/kasan.c:553 kasan_slab_alloc+0x14/0x20 mm/kasan/kasan.c:490 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc_node mm/slub.c:2705 [inline] slab_alloc mm/slub.c:2713 [inline] kmem_cache_alloc+0x14c/0x388 mm/slub.c:2718 kmem_cache_zalloc include/linux/slab.h:697 [inline] net_alloc net/core/net_namespace.c:384 [inline] copy_net_ns+0xc4/0x2d0 net/core/net_namespace.c:424 create_new_namespaces+0x300/0x658 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xa0/0x198 kernel/nsproxy.c:206 ksys_unshare+0x340/0x628 kernel/fork.c:2577 __do_sys_unshare kernel/fork.c:2645 [inline] __se_sys_unshare kernel/fork.c:2643 [inline] __arm64_sys_unshare+0x38/0x58 kernel/fork.c:2643 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall arch/arm64/kernel/syscall.c:47 [inline] el0_svc_common+0x168/0x390 arch/arm64/kernel/syscall.c:83 el0_svc_handler+0x60/0xd0 arch/arm64/kernel/syscall.c:129 el0_svc+0x8/0xc arch/arm64/kernel/entry.S:960 Freed by task 264: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x114/0x220 mm/kasan/kasan.c:521 kasan_slab_free+0x10/0x18 mm/kasan/kasan.c:528 slab_free_hook mm/slub.c:1370 [inline] slab_free_freelist_hook mm/slub.c:1397 [inline] slab_free mm/slub.c:2952 [inline] kmem_cache_free+0xb8/0x3a8 mm/slub.c:2968 net_free net/core/net_namespace.c:400 [inline] net_drop_ns.part.6+0x78/0x90 net/core/net_namespace.c:407 net_drop_ns net/core/net_namespace.c:406 [inline] cleanup_net+0x53c/0x6d8 net/core/net_namespace.c:569 process_one_work+0x6e8/0x1700 kernel/workqueue.c:2153 worker_thread+0x3b0/0xdd0 kernel/workqueue.c:2296 kthread+0x2f0/0x378 kernel/kthread.c:255 ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:1117 The buggy address belongs to the object at ffff8003496a3f80 which belongs to the cache net_namespace of size 7872 The buggy address is located 1796 bytes inside of 7872-byte region [ffff8003496a3f80, ffff8003496a5e40) The buggy address belongs to the page: page:ffff7e000d25a800 count:1 mapcount:0 mapping:ffff80036ce4b000 index:0x0 compound_mapcount: 0 flags: 0xffffe0000008100(slab|head) raw: 0ffffe0000008100 dead000000000100 dead000000000200 ffff80036ce4b000 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8003496a4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8003496a4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8003496a4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8003496a4700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8003496a4780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fixes: 467fa15356ac("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") Reported-by: Hulk Robot Signed-off-by: Mao Wenan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

RDS: fix rds_tcp_init() error path

2016-08-10T09:49:29+00:00

commit 3dad5424adfb346c871847d467f97dcdca64ea97 upstream. If register_pernet_subsys() fails, we shouldn't try to call unregister_pernet_subsys(). Fixes: 467fa15356 ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.") Cc: Sowmini Varadhan Cc: David S. Miller Signed-off-by: Vegard Nossum Acked-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

RDS-TCP: Do not bloat sndbuf/rcvbuf in rds_tcp_tune

2015-10-05T10:34:53+00:00

Using the value of RDS_TCP_DEFAULT_BUFSIZE (128K) clobbers efficient use of TSO because it inflates the size_goal that is computed in tcp_sendmsg/tcp_sendpage and skews packet latency, and the default values for these parameters actually results in significantly better performance. In request-response tests using rds-stress with a packet size of 100K with 16 threads (test parameters -q 100000 -a 256 -t16 -d16) between a single pair of IP addresses achieves a throughput of 6-8 Gbps. Without this patch, throughput maxes at 2-3 Gbps under equivalent conditions on these platforms. Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller

RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.

2015-08-07T18:29:58+00:00

Register pernet subsys init/stop functions that will set up and tear down per-net RDS-TCP listen endpoints. Unregister pernet subusys functions on 'modprobe -r' to clean up these end points. Enable keepalive on both accept and connect socket endpoints. The keepalive timer expiration will ensure that client socket endpoints will be removed as appropriate from the netns when an interface is removed from a namespace. Register a device notifier callback that will clean up all sockets (and thus avoid the need to wait for keepalive timeout) when the loopback device is unregistered from the netns indicating that the netns is getting deleted. Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller

RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than init_net

2015-08-07T18:29:57+00:00

Open the sockets calling sock_create_kern() with the correct struct net pointer, and use that struct net pointer when verifying the address passed to rds_bind(). Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller

net: Fix files explicitly needing to include module.h

2011-10-31T23:30:28+00:00

With calls to modular infrastructure, these files really needs the full module.h header. Call it out so some of the cleanups of implicit and unrequired includes elsewhere can be cleaned up. Signed-off-by: Paul Gortmaker

rds: Remove kfreed tcp conn from list

2010-11-04T01:50:07+00:00

All the rds_tcp_connection objects are stored list, but when being freed it should be removed from there. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller

rds: make local functions/variables static

2010-10-21T11:26:39+00:00

The RDS protocol has lots of functions that should be declared static. rds_message_get/add_version_extension is removed since it defined but never used. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller