linux/include/net/sctp/structs.h

2017 lines
63 KiB

sctp: Fix skb_over_panic resulting from multiple invalid parameter errors (CVE-2010-1173) (v4) 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>
2010-04-28 10:30:59 +00:00
sctp: Fix a race between ICMP protocol unreachable and connect() ICMP protocol unreachable handling completely disregarded the fact that the user may have locked the socket. It proceeded to destroy the association, even though the user may have held the lock and had a ref on the association. This resulted in the following: Attempt to release alive inet socket f6afcc00 ========================= [ BUG: held lock freed! ] ------------------------- somenu/2672 is freeing memory f6afcc00-f6afcfff, with a lock still held there! (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c 1 lock held by somenu/2672: #0: (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c stack backtrace: Pid: 2672, comm: somenu Not tainted 2.6.32-telco #55 Call Trace: [<c1232266>] ? printk+0xf/0x11 [<c1038553>] debug_check_no_locks_freed+0xce/0xff [<c10620b4>] kmem_cache_free+0x21/0x66 [<c1185f25>] __sk_free+0x9d/0xab [<c1185f9c>] sk_free+0x1c/0x1e [<c1216e38>] sctp_association_put+0x32/0x89 [<c1220865>] __sctp_connect+0x36d/0x3f4 [<c122098a>] ? sctp_connect+0x13/0x4c [<c102d073>] ? autoremove_wake_function+0x0/0x33 [<c12209a8>] sctp_connect+0x31/0x4c [<c11d1e80>] inet_dgram_connect+0x4b/0x55 [<c11834fa>] sys_connect+0x54/0x71 [<c103a3a2>] ? lock_release_non_nested+0x88/0x239 [<c1054026>] ? might_fault+0x42/0x7c [<c1054026>] ? might_fault+0x42/0x7c [<c11847ab>] sys_socketcall+0x6d/0x178 [<c10da994>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002959>] syscall_call+0x7/0xb This was because the sctp_wait_for_connect() would aqcure the socket lock and then proceed to release the last reference count on the association, thus cause the fully destruction path to finish freeing the socket. The simplest solution is to start a very short timer in case the socket is owned by user. When the timer expires, we can do some verification and be able to do the release properly. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-06 00:56:07 -07:00