lwn.git/net/ipv4/inet_connection_sock.c, branch v3.8-rc5

inet: Fix kmemleak in tcp_v4/6_syn_recv_sock and dccp_v4/6_request_recv_sock

2012-12-14T18:14:07+00:00

If in either of the above functions inet_csk_route_child_sock() or __inet_inherit_port() fails, the newsk will not be freed: unreferenced object 0xffff88022e8a92c0 (size 1592): comm "softirq", pid 0, jiffies 4294946244 (age 726.160s) hex dump (first 32 bytes): 0a 01 01 01 0a 01 01 02 00 00 00 00 a7 cc 16 00 ................ 02 00 03 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmemleak_alloc+0x21/0x3e [] kmem_cache_alloc+0xb5/0xc5 [] sk_prot_alloc.isra.53+0x2b/0xcd [] sk_clone_lock+0x16/0x21e [] inet_csk_clone_lock+0x10/0x7b [] tcp_create_openreq_child+0x21/0x481 [] tcp_v4_syn_recv_sock+0x3a/0x23b [] tcp_check_req+0x29f/0x416 [] tcp_v4_do_rcv+0x161/0x2bc [] tcp_v4_rcv+0x6c9/0x701 [] ip_local_deliver_finish+0x70/0xc4 [] ip_local_deliver+0x4e/0x7f [] ip_rcv_finish+0x1fc/0x233 [] ip_rcv+0x217/0x267 [] __netif_receive_skb+0x49e/0x553 [] netif_receive_skb+0x50/0x82 This happens, because sk_clone_lock initializes sk_refcnt to 2, and thus a single sock_put() is not enough to free the memory. Additionally, things like xfrm, memcg, cookie_values,... may have been initialized. We have to free them properly. This is fixed by forcing a call to tcp_done(), ending up in inet_csk_destroy_sock, doing the final sock_put(). tcp_done() is necessary, because it ends up doing all the cleanup on xfrm, memcg, cookie_values, xfrm,... Before calling tcp_done, we have to set the socket to SOCK_DEAD, to force it entering inet_csk_destroy_sock. To avoid the warning in inet_csk_destroy_sock, inet_num has to be set to 0. As inet_csk_destroy_sock does a dec on orphan_count, we first have to increase it. Calling tcp_done() allows us to remove the calls to tcp_clear_xmit_timer() and tcp_cleanup_congestion_control(). A similar approach is taken for dccp by calling dccp_done(). This is in the kernel since 093d282321 (tproxy: fix hash locking issue when using port redirection in __inet_inherit_port()), thus since version >= 2.6.37. Signed-off-by: Christoph Paasch Signed-off-by: David S. Miller

tcp: better retrans tracking for defer-accept

2012-11-03T18:45:00+00:00

For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng Signed-off-by: Eric Dumazet Cc: Julian Anastasov Cc: Vijay Subramanian Cc: Elliott Hughes Cc: Neal Cardwell Signed-off-by: David S. Miller

ipv4: introduce rt_uses_gateway

2012-10-08T21:42:36+00:00

Add new flag to remember when route is via gateway. We will use it to allow rt_gateway to contain address of directly connected host for the cases when DST_NOCACHE is used or when the NH exception caches per-destination route without DST_NOCACHE flag, i.e. when routes are not used for other destinations. By this way we force the neighbour resolving to work with the routed destination but we can use different address in the packet, feature needed for IPVS-DR where original packet for virtual IP is routed via route to real IP. Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller

tcp: fix TFO regression

2012-09-06T18:21:10+00:00

Fengguang Wu reported various panics and bisected to commit 8336886f786fdac (tcp: TCP Fast Open Server - support TFO listeners) Fix this by making sure socket is a TCP socket before accessing TFO data structures. [ 233.046014] kfree_debugcheck: out of range ptr ea6000000bb8h. [ 233.047399] ------------[ cut here ]------------ [ 233.048393] kernel BUG at /c/kernel-tests/src/stable/mm/slab.c:3074! [ 233.048393] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 233.048393] Modules linked in: [ 233.048393] CPU 0 [ 233.048393] Pid: 3929, comm: trinity-watchdo Not tainted 3.6.0-rc3+ #4192 Bochs Bochs [ 233.048393] RIP: 0010:[] [] kfree_debugcheck+0x27/0x2d [ 233.048393] RSP: 0018:ffff88000facbca8 EFLAGS: 00010092 [ 233.048393] RAX: 0000000000000031 RBX: 0000ea6000000bb8 RCX: 00000000a189a188 [ 233.048393] RDX: 000000000000a189 RSI: ffffffff8108ad32 RDI: ffffffff810d30f9 [ 233.048393] RBP: ffff88000facbcb8 R08: 0000000000000002 R09: ffffffff843846f0 [ 233.048393] R10: ffffffff810ae37c R11: 0000000000000908 R12: 0000000000000202 [ 233.048393] R13: ffffffff823dbd5a R14: ffff88000ec5bea8 R15: ffffffff8363c780 [ 233.048393] FS: 00007faa6899c700(0000) GS:ffff88001f200000(0000) knlGS:0000000000000000 [ 233.048393] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 233.048393] CR2: 00007faa6841019c CR3: 0000000012c82000 CR4: 00000000000006f0 [ 233.048393] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 233.048393] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 233.048393] Process trinity-watchdo (pid: 3929, threadinfo ffff88000faca000, task ffff88000faec600) [ 233.048393] Stack: [ 233.048393] 0000000000000000 0000ea6000000bb8 ffff88000facbce8 ffffffff8116ad81 [ 233.048393] ffff88000ff588a0 ffff88000ff58850 ffff88000ff588a0 0000000000000000 [ 233.048393] ffff88000facbd08 ffffffff823dbd5a ffffffff823dbcb0 ffff88000ff58850 [ 233.048393] Call Trace: [ 233.048393] [] kfree+0x5f/0xca [ 233.048393] [] inet_sock_destruct+0xaa/0x13c [ 233.048393] [] ? inet_sk_rebuild_header +0x319/0x319 [ 233.048393] [] __sk_free+0x21/0x14b [ 233.048393] [] sk_free+0x26/0x2a [ 233.048393] [] sctp_close+0x215/0x224 [ 233.048393] [] ? lock_release+0x16f/0x1b9 [ 233.048393] [] inet_release+0x7e/0x85 [ 233.048393] [] sock_release+0x1f/0x77 [ 233.048393] [] sock_close+0x27/0x2b [ 233.048393] [] __fput+0x101/0x20a [ 233.048393] [] ____fput+0xe/0x10 [ 233.048393] [] task_work_run+0x5d/0x75 [ 233.048393] [] do_exit+0x290/0x7f5 [ 233.048393] [] ? retint_swapgs+0x13/0x1b [ 233.048393] [] do_group_exit+0x7b/0xba [ 233.048393] [] sys_exit_group+0x17/0x17 [ 233.048393] [] tracesys+0xdd/0xe2 [ 233.048393] Code: 59 01 5d c3 55 48 89 e5 53 41 50 0f 1f 44 00 00 48 89 fb e8 d4 b0 f0 ff 84 c0 75 11 48 89 de 48 c7 c7 fc fa f7 82 e8 0d 0f 57 01 <0f> 0b 5f 5b 5d c3 55 48 89 e5 0f 1f 44 00 00 48 63 87 d8 00 00 [ 233.048393] RIP [] kfree_debugcheck+0x27/0x2d [ 233.048393] RSP Reported-by: Fengguang Wu Tested-by: Fengguang Wu Signed-off-by: Eric Dumazet Cc: "H.K. Jerry Chu" Acked-by: Neal Cardwell Acked-by: H.K. Jerry Chu Signed-off-by: David S. Miller

tcp: TCP Fast Open Server - support TFO listeners

2012-09-01T00:02:19+00:00

This patch builds on top of the previous patch to add the support for TFO listeners. This includes - 1. allocating, properly initializing, and managing the per listener fastopen_queue structure when TFO is enabled 2. changes to the inet_csk_accept code to support TFO. E.g., the request_sock can no longer be freed upon accept(), not until 3WHS finishes 3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg() if it's a TFO socket 4. properly closing a TFO listener, and a TFO socket before 3WHS finishes 5. supporting TCP_FASTOPEN socket option 6. modifying tcp_check_req() to use to check a TFO socket as well as request_sock 7. supporting TCP's TFO cookie option 8. adding a new SYN-ACK retransmit handler to use the timer directly off the TFO socket rather than the listener socket. Note that TFO server side will not retransmit anything other than SYN-ACK until the 3WHS is completed. The patch also contains an important function "reqsk_fastopen_remove()" to manage the somewhat complex relation between a listener, its request_sock, and the corresponding child socket. See the comment above the function for the detail. Signed-off-by: H.K. Jerry Chu Cc: Yuchung Cheng Cc: Neal Cardwell Cc: Eric Dumazet Cc: Tom Herbert Signed-off-by: David S. Miller

ipv4: Use newinet->inet_opt in inet_csk_route_child_sock()

2012-08-21T21:49:11+00:00

Since 0e734419923bd ("ipv4: Use inet_csk_route_child_sock() in DCCP and TCP."), inet_csk_route_child_sock() is called instead of inet_csk_route_req(). However, after creating the child-sock in tcp/dccp_v4_syn_recv_sock(), ireq->opt is set to NULL, before calling inet_csk_route_child_sock(). Thus, inside inet_csk_route_child_sock() opt is always NULL and the SRR-options are not respected anymore. Packets sent by the server won't have the correct destination-IP. This patch fixes it by accessing newinet->inet_opt instead of ireq->opt inside inet_csk_route_child_sock(). Reported-by: Luca Boccassi Signed-off-by: Christoph Paasch Signed-off-by: David S. Miller

ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.

2012-07-20T20:36:54+00:00

Signed-off-by: David S. Miller

ipv4: Adjust semantics of rt->rt_gateway.

2012-07-20T20:31:20+00:00

In order to allow prefixed routes, we have to adjust how rt_gateway is set and interpreted. The new interpretation is: 1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr 2) rt_gateway != 0, destination requires a nexthop gateway Abstract the fetching of the proper nexthop value using a new inline helper, rt_nexthop(), as suggested by Joe Perches. Signed-off-by: David S. Miller Tested-by: Vijay Subramanian

ipv4: fix rcu splat

2012-07-17T20:47:33+00:00

free_nh_exceptions() should use rcu_dereference_protected(..., 1) since its called after one RCU grace period. Also add some const-ification in recent code. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()

2012-07-17T10:29:28+00:00

This will be used so that we can compose a full flow key. Even though we have a route in this context, we need more. In the future the routes will be without destination address, source address, etc. keying. One ipv4 route will cover entire subnets, etc. In this environment we have to have a way to possess persistent storage for redirects and PMTU information. This persistent storage will exist in the FIB tables, and that's why we'll need to be able to rebuild a full lookup flow key here. Using that flow key will do a fib_lookup() and create/update the persistent entry. Signed-off-by: David S. Miller