Date:2010-04-28 10:47:21 (12 years 5 months ago)
Author:Wei Yongjun
Commit:a8170c35e738d62e9919ce5b109cf4ed66e95bde
Message:sctp: fix to calc the INIT/INIT-ACK chunk length correctly is set

When calculating the INIT/INIT-ACK chunk length, we should not
only account the length of parameters, but also the parameters
zero padding length, such as AUTH HMACS parameter and CHUNKS
parameter. Without the parameters zero padding length we may get
following oops.

skb_over_panic: text:ce2068d2 len:130 put:6 head:cac3fe00 data:cac3fe00 tail:0xcac3fe82 end:0xcac3fe80 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:127!
invalid opcode: 0000 [#2] SMP
last sysfs file: /sys/module/aes_generic/initstate
Modules linked in: authenc ......

Pid: 4102, comm: sctp_darn Tainted: G D 2.6.34-rc2 #6
EIP: 0060:[<c0607630>] EFLAGS: 00010282 CPU: 0
EIP is at skb_over_panic+0x37/0x3e
EAX: 00000078 EBX: c07c024b ECX: c07c02b9 EDX: cb607b78
ESI: 00000000 EDI: cac3fe7a EBP: 00000002 ESP: cb607b74
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process sctp_darn (pid: 4102, ti=cb607000 task=cabdc990 task.ti=cb607000)
Stack:
c07c02b9 ce2068d2 00000082 00000006 cac3fe00 cac3fe00 cac3fe82 cac3fe80
<0> c07c024b cac3fe7c cac3fe7a c0608dec ca986e80 ce2068d2 00000006 0000007a
<0> cb8120ca ca986e80 cb812000 00000003 cb8120c4 ce208a25 cb8120ca cadd9400
Call Trace:
[<ce2068d2>] ? sctp_addto_chunk+0x45/0x85 [sctp]
[<c0608dec>] ? skb_put+0x2e/0x32
[<ce2068d2>] ? sctp_addto_chunk+0x45/0x85 [sctp]
[<ce208a25>] ? sctp_make_init+0x279/0x28c [sctp]
[<c0686a92>] ? apic_timer_interrupt+0x2a/0x30
[<ce1fdc0b>] ? sctp_sf_do_prm_asoc+0x2b/0x7b [sctp]
[<ce202823>] ? sctp_do_sm+0xa0/0x14a [sctp]
[<ce2133b9>] ? sctp_pname+0x0/0x14 [sctp]
[<ce211d72>] ? sctp_primitive_ASSOCIATE+0x2b/0x31 [sctp]
[<ce20f3cf>] ? sctp_sendmsg+0x7a0/0x9eb [sctp]
[<c064eb1e>] ? inet_sendmsg+0x3b/0x43
[<c04244b7>] ? task_tick_fair+0x2d/0xd9
[<c06031e1>] ? sock_sendmsg+0xa7/0xc1
[<c0416afe>] ? smp_apic_timer_interrupt+0x6b/0x75
[<c0425123>] ? dequeue_task_fair+0x34/0x19b
[<c0446abb>] ? sched_clock_local+0x17/0x11e
[<c052ea87>] ? _copy_from_user+0x2b/0x10c
[<c060ab3a>] ? verify_iovec+0x3c/0x6a
[<c06035ca>] ? sys_sendmsg+0x186/0x1e2
[<c042176b>] ? __wake_up_common+0x34/0x5b
[<c04240c2>] ? __wake_up+0x2c/0x3b
[<c057e35c>] ? tty_wakeup+0x43/0x47
[<c04430f2>] ? remove_wait_queue+0x16/0x24
[<c0580c94>] ? n_tty_read+0x5b8/0x65e
[<c042be02>] ? default_wake_function+0x0/0x8
[<c0604e0e>] ? sys_socketcall+0x17f/0x1cd
[<c040264c>] ? sysenter_do_call+0x12/0x22
Code: 0f 45 de 53 ff b0 98 00 00 00 ff b0 94 ......
EIP: [<c0607630>] skb_over_panic+0x37/0x3e SS:ESP 0068:cb607b74

To reproduce:

# modprobe sctp
# echo 1 > /proc/sys/net/sctp/addip_enable
# echo 1 > /proc/sys/net/sctp/auth_enable
# sctp_test -H 3ffe:501:ffff:100:20c:29ff:fe4d:f37e -P 800 -l
# sctp_darn -H 3ffe:501:ffff:100:20c:29ff:fe4d:f37e -P 900 -h 192.168.0.21 -p 800 -I -s -t
sctp_darn ready to send...
3ffe:501:ffff:100:20c:29ff:fe4d:f37e:900-192.168.0.21:800 Interactive mode> bindx-add=192.168.0.21
3ffe:501:ffff:100:20c:29ff:fe4d:f37e:900-192.168.0.21:800 Interactive mode> bindx-add=192.168.1.21
3ffe:501:ffff:100:20c:29ff:fe4d:f37e:900-192.168.0.21:800 Interactive mode> snd=10

------------------------------------------------------------------
eth0 has addresses: 3ffe:501:ffff:100:20c:29ff:fe4d:f37e and 192.168.0.21
eth1 has addresses: 192.168.1.21
------------------------------------------------------------------

Reported-by: George Cheimonidis <gchimon@gmail.com>
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Files: net/sctp/sm_make_chunk.c (5 diffs)

Change Details

net/sctp/sm_make_chunk.c
208208    sp = sctp_sk(asoc->base.sk);
209209    num_types = sp->pf->supported_addrs(sp, types);
210210
211    chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
211    chunksize = sizeof(init) + addrs_len;
212    chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
212213    chunksize += sizeof(ecap_param);
213214
214215    if (sctp_prsctp_enable)
...... 
238239        /* Add HMACS parameter length if any were defined */
239240        auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
240241        if (auth_hmacs->length)
241            chunksize += ntohs(auth_hmacs->length);
242            chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
242243        else
243244            auth_hmacs = NULL;
244245
245246        /* Add CHUNKS parameter length */
246247        auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
247248        if (auth_chunks->length)
248            chunksize += ntohs(auth_chunks->length);
249            chunksize += WORD_ROUND(ntohs(auth_chunks->length));
249250        else
250251            auth_chunks = NULL;
251252
...... 
255256
256257    /* If we have any extensions to report, account for that */
257258    if (num_ext)
258        chunksize += sizeof(sctp_supported_ext_param_t) + num_ext;
259        chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
260                    num_ext);
259261
260262    /* RFC 2960 3.3.2 Initiation (INIT) (1)
261263     *
...... 
397399
398400        auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
399401        if (auth_hmacs->length)
400            chunksize += ntohs(auth_hmacs->length);
402            chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
401403        else
402404            auth_hmacs = NULL;
403405
404406        auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
405407        if (auth_chunks->length)
406            chunksize += ntohs(auth_chunks->length);
408            chunksize += WORD_ROUND(ntohs(auth_chunks->length));
407409        else
408410            auth_chunks = NULL;
409411
...... 
412414    }
413415
414416    if (num_ext)
415        chunksize += sizeof(sctp_supported_ext_param_t) + num_ext;
417        chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
418                    num_ext);
416419
417420    /* Now allocate and fill out the chunk. */
418421    retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);

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