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Ok, version 4 Change Notes: 1) Minor cleanups, from Vlads notes Summary: Hey- Recently, it was reported to me that the kernel could oops in the following way: <5> kernel BUG at net/core/skbuff.c:91! <5> invalid operand: 0000 [#1] <5> Modules linked in: sctp netconsole nls_utf8 autofs4 sunrpc iptable_filter ip_tables cpufreq_powersave parport_pc lp parport vmblock(U) vsock(U) vmci(U) vmxnet(U) vmmemctl(U) vmhgfs(U) acpiphp dm_mirror dm_mod button battery ac md5 ipv6 uhci_hcd ehci_hcd snd_ens1371 snd_rawmidi snd_seq_device snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc snd_ac97_codec snd soundcore pcnet32 mii floppy ext3 jbd ata_piix libata mptscsih mptsas mptspi mptscsi mptbase sd_mod scsi_mod <5> CPU: 0 <5> EIP: 0060:[<c02bff27>] Not tainted VLI <5> EFLAGS: 00010216 (2.6.9-89.0.25.EL) <5> EIP is at skb_over_panic+0x1f/0x2d <5> eax: 0000002c ebx: c033f461 ecx: c0357d96 edx: c040fd44 <5> esi: c033f461 edi: df653280 ebp: 00000000 esp: c040fd40 <5> ds: 007b es: 007b ss: 0068 <5> Process swapper (pid: 0, threadinfo=c040f000 task=c0370be0) <5> Stack: c0357d96 e0c29478 00000084 00000004 c033f461 df653280 d7883180 e0c2947d <5> 00000000 00000080 df653490 00000004 de4f1ac0 de4f1ac0 00000004 df653490 <5> 00000001 e0c2877a 08000800 de4f1ac0 df653490 00000000 e0c29d2e 00000004 <5> Call Trace: <5> [<e0c29478>] sctp_addto_chunk+0xb0/0x128 [sctp] <5> [<e0c2947d>] sctp_addto_chunk+0xb5/0x128 [sctp] <5> [<e0c2877a>] sctp_init_cause+0x3f/0x47 [sctp] <5> [<e0c29d2e>] sctp_process_unk_param+0xac/0xb8 [sctp] <5> [<e0c29e90>] sctp_verify_init+0xcc/0x134 [sctp] <5> [<e0c20322>] sctp_sf_do_5_1B_init+0x83/0x28e [sctp] <5> [<e0c25333>] sctp_do_sm+0x41/0x77 [sctp] <5> [<c01555a4>] cache_grow+0x140/0x233 <5> [<e0c26ba1>] sctp_endpoint_bh_rcv+0xc5/0x108 [sctp] <5> [<e0c2b863>] sctp_inq_push+0xe/0x10 [sctp] <5> [<e0c34600>] sctp_rcv+0x454/0x509 [sctp] <5> [<e084e017>] ipt_hook+0x17/0x1c [iptable_filter] <5> [<c02d005e>] nf_iterate+0x40/0x81 <5> [<c02e0bb9>] ip_local_deliver_finish+0x0/0x151 <5> [<c02e0c7f>] ip_local_deliver_finish+0xc6/0x151 <5> [<c02d0362>] nf_hook_slow+0x83/0xb5 <5> [<c02e0bb2>] ip_local_deliver+0x1a2/0x1a9 <5> [<c02e0bb9>] ip_local_deliver_finish+0x0/0x151 <5> [<c02e103e>] ip_rcv+0x334/0x3b4 <5> [<c02c66fd>] netif_receive_skb+0x320/0x35b <5> [<e0a0928b>] init_stall_timer+0x67/0x6a [uhci_hcd] <5> [<c02c67a4>] process_backlog+0x6c/0xd9 <5> [<c02c690f>] net_rx_action+0xfe/0x1f8 <5> [<c012a7b1>] __do_softirq+0x35/0x79 <5> [<c0107efb>] handle_IRQ_event+0x0/0x4f <5> [<c01094de>] do_softirq+0x46/0x4d Its an skb_over_panic BUG halt that results from processing an init chunk in which too many of its variable length parameters are in some way malformed. The problem is in sctp_process_unk_param: if (NULL == *errp) *errp = sctp_make_op_error_space(asoc, chunk, ntohs(chunk->chunk_hdr->length)); if (*errp) { sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, WORD_ROUND(ntohs(param.p->length))); sctp_addto_chunk(*errp, WORD_ROUND(ntohs(param.p->length)), param.v); When we allocate an error chunk, we assume that the worst case scenario requires that we have chunk_hdr->length data allocated, which would be correct nominally, given that we call sctp_addto_chunk for the violating parameter. Unfortunately, we also, in sctp_init_cause insert a sctp_errhdr_t structure into the error chunk, so the worst case situation in which all parameters are in violation requires chunk_hdr->length+(sizeof(sctp_errhdr_t)*param_count) bytes of data. The result of this error is that a deliberately malformed packet sent to a listening host can cause a remote DOS, described in CVE-2010-1173: http://cve.mitre.org/cgi-bin/cvename.cgi?name=2010-1173 I've tested the below fix and confirmed that it fixes the issue. We move to a strategy whereby we allocate a fixed size error chunk and ignore errors we don't have space to report. Tested by me successfully Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| auth.h | ||
| checksum.h | ||
| command.h | ||
| constants.h | ||
| sctp.h | ||
| sm.h | ||
| structs.h | ||
| tsnmap.h | ||
| ulpevent.h | ||
| ulpqueue.h | ||
| user.h | ||