[kernel] r15588 - in dists/sid/linux-2.6/debian: . patches/bugfix/all patches/series
Dann Frazier
dannf at alioth.debian.org
Fri Apr 30 06:04:40 UTC 2010
Author: dannf
Date: Fri Apr 30 06:04:07 2010
New Revision: 15588
Log:
sctp: Fix skb_over_panic resulting from multiple invalid parameter
errors (CVE-2010-1173)
Added:
dists/sid/linux-2.6/debian/patches/bugfix/all/sctp-fix-skb_over_panic-resulting-from-multiple-invalid-parameter-errors.patch
Modified:
dists/sid/linux-2.6/debian/changelog
dists/sid/linux-2.6/debian/patches/series/12
Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog Fri Apr 30 03:14:24 2010 (r15587)
+++ dists/sid/linux-2.6/debian/changelog Fri Apr 30 06:04:07 2010 (r15588)
@@ -62,6 +62,8 @@
[ dann frazier ]
* Add DRBD backport
+ * sctp: Fix skb_over_panic resulting from multiple invalid parameter
+ errors (CVE-2010-1173)
[ Aurelien Jarno ]
* [sh4] Add a sh7751r flavour.
Added: dists/sid/linux-2.6/debian/patches/bugfix/all/sctp-fix-skb_over_panic-resulting-from-multiple-invalid-parameter-errors.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/all/sctp-fix-skb_over_panic-resulting-from-multiple-invalid-parameter-errors.patch Fri Apr 30 06:04:07 2010 (r15588)
@@ -0,0 +1,218 @@
+commit 5fa782c2f5ef6c2e4f04d3e228412c9b4a4c8809
+Author: Neil Horman <nhorman at tuxdriver.com>
+Date: Wed Apr 28 10:30:59 2010 +0000
+
+ 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 at tuxdriver.com>
+ Acked-by: Vlad Yasevich <vladislav.yasevich at hp.com>
+ Signed-off-by: David S. Miller <davem at davemloft.net>
+
+diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
+index ff30177..597f8e2 100644
+--- a/include/net/sctp/structs.h
++++ b/include/net/sctp/structs.h
+@@ -778,6 +778,7 @@ int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
+ struct iovec *data);
+ void sctp_chunk_free(struct sctp_chunk *);
+ void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
++void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
+ struct sctp_chunk *sctp_chunkify(struct sk_buff *,
+ const struct sctp_association *,
+ struct sock *);
+diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
+index 0fd5b4c..30c1767 100644
+--- a/net/sctp/sm_make_chunk.c
++++ b/net/sctp/sm_make_chunk.c
+@@ -108,7 +108,7 @@ static const struct sctp_paramhdr prsctp_param = {
+ cpu_to_be16(sizeof(struct sctp_paramhdr)),
+ };
+
+-/* A helper to initialize to initialize an op error inside a
++/* A helper to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk.
+ */
+@@ -125,6 +125,29 @@ void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
+ chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
+ }
+
++/* A helper to initialize an op error inside a
++ * provided chunk, as most cause codes will be embedded inside an
++ * abort chunk. Differs from sctp_init_cause in that it won't oops
++ * if there isn't enough space in the op error chunk
++ */
++int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
++ size_t paylen)
++{
++ sctp_errhdr_t err;
++ __u16 len;
++
++ /* Cause code constants are now defined in network order. */
++ err.cause = cause_code;
++ len = sizeof(sctp_errhdr_t) + paylen;
++ err.length = htons(len);
++
++ if (skb_tailroom(chunk->skb) > len)
++ return -ENOSPC;
++ chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
++ sizeof(sctp_errhdr_t),
++ &err);
++ return 0;
++}
+ /* 3.3.2 Initiation (INIT) (1)
+ *
+ * This chunk is used to initiate a SCTP association between two
+@@ -1132,6 +1155,24 @@ nodata:
+ return retval;
+ }
+
++/* Create an Operation Error chunk of a fixed size,
++ * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
++ * This is a helper function to allocate an error chunk for
++ * for those invalid parameter codes in which we may not want
++ * to report all the errors, if the incomming chunk is large
++ */
++static inline struct sctp_chunk *sctp_make_op_error_fixed(
++ const struct sctp_association *asoc,
++ const struct sctp_chunk *chunk)
++{
++ size_t size = asoc ? asoc->pathmtu : 0;
++
++ if (!size)
++ size = SCTP_DEFAULT_MAXSEGMENT;
++
++ return sctp_make_op_error_space(asoc, chunk, size);
++}
++
+ /* Create an Operation Error chunk. */
+ struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+@@ -1374,6 +1415,18 @@ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
+ return target;
+ }
+
++/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
++ * space in the chunk
++ */
++void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
++ int len, const void *data)
++{
++ if (skb_tailroom(chunk->skb) > len)
++ return sctp_addto_chunk(chunk, len, data);
++ else
++ return NULL;
++}
++
+ /* Append bytes from user space to the end of a chunk. Will panic if
+ * chunk is not big enough.
+ * Returns a kernel err value.
+@@ -1977,13 +2030,12 @@ static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
+ * returning multiple unknown parameters.
+ */
+ if (NULL == *errp)
+- *errp = sctp_make_op_error_space(asoc, chunk,
+- ntohs(chunk->chunk_hdr->length));
++ *errp = sctp_make_op_error_fixed(asoc, chunk);
+
+ if (*errp) {
+- sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
++ sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+ WORD_ROUND(ntohs(param.p->length)));
+- sctp_addto_chunk(*errp,
++ sctp_addto_chunk_fixed(*errp,
+ WORD_ROUND(ntohs(param.p->length)),
+ param.v);
+ } else {
Modified: dists/sid/linux-2.6/debian/patches/series/12
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/12 Fri Apr 30 03:14:24 2010 (r15587)
+++ dists/sid/linux-2.6/debian/patches/series/12 Fri Apr 30 06:04:07 2010 (r15588)
@@ -59,3 +59,4 @@
+ bugfix/all/libiscsi-regression-fix-header-digest-errors.patch
+ bugfix/all/revert-percpu-stable-changes.patch
+ bugfix/all/virtio_net-Make-delayed-refill-more-reliable.patch
++ bugfix/all/sctp-fix-skb_over_panic-resulting-from-multiple-invalid-parameter-errors.patch
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