CVE-2014-7841 sctp: NULL ptr deref on malformed packet (rhbz 1163087 1163095)

This commit is contained in:
Josh Boyer 2014-11-12 09:24:30 -05:00
parent d74e638376
commit b3a8f8f907
2 changed files with 86 additions and 0 deletions

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@ -619,6 +619,9 @@ Patch26065: sched-Remove-lockdep-check-in-sched_move_task.patch
#rhbz 1161805
Patch26066: ahci-disable-MSI-instead-of-NCQ-on-Samsung-pci-e-SSD.patch
#CVE-2014-7841 rhbz 1163087 1163095
Patch26067: net-sctp-fix-NULL-pointer-dereference-in-af-from_add.patch
# git clone ssh://git.fedorahosted.org/git/kernel-arm64.git, git diff master...devel
Patch30000: kernel-arm64.patch
@ -1347,6 +1350,9 @@ ApplyPatch sched-Remove-lockdep-check-in-sched_move_task.patch
#rhbz 1161805
ApplyPatch ahci-disable-MSI-instead-of-NCQ-on-Samsung-pci-e-SSD.patch
#CVE-2014-7841 rhbz 1163087 1163095
ApplyPatch net-sctp-fix-NULL-pointer-dereference-in-af-from_add.patch
%if 0%{?aarch64patches}
ApplyPatch kernel-arm64.patch
%ifnarch aarch64 # this is stupid, but i want to notice before secondary koji does.
@ -2215,6 +2221,9 @@ fi
# ||----w |
# || ||
%changelog
* Wed Nov 12 2014 Josh Boyer <jwboyer@fedoraproject.org>
- CVE-2014-7841 sctp: NULL ptr deref on malformed packet (rhbz 1163087 1163095)
* Tue Nov 11 2014 Kyle McMartin <kyle@fedoraproject.org> - 3.18.0-0.rc4.git0.2
- Re-enable kernel-arm64.patch, and fix up merge conflicts with 3.18-rc4

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@ -0,0 +1,77 @@
From: Daniel Borkmann <dborkman@redhat.com>
Date: Mon, 10 Nov 2014 17:54:26 +0100
Subject: [PATCH] net: sctp: fix NULL pointer dereference in
af->from_addr_param on malformed packet
An SCTP server doing ASCONF will panic on malformed INIT ping-of-death
in the form of:
------------ INIT[PARAM: SET_PRIMARY_IP] ------------>
While the INIT chunk parameter verification dissects through many things
in order to detect malformed input, it misses to actually check parameters
inside of parameters. E.g. RFC5061, section 4.2.4 proposes a 'set primary
IP address' parameter in ASCONF, which has as a subparameter an address
parameter.
So an attacker may send a parameter type other than SCTP_PARAM_IPV4_ADDRESS
or SCTP_PARAM_IPV6_ADDRESS, param_type2af() will subsequently return 0
and thus sctp_get_af_specific() returns NULL, too, which we then happily
dereference unconditionally through af->from_addr_param().
The trace for the log:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
IP: [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
PGD 0
Oops: 0000 [#1] SMP
[...]
Pid: 0, comm: swapper Not tainted 2.6.32-504.el6.x86_64 #1 Bochs Bochs
RIP: 0010:[<ffffffffa01e9c62>] [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
[...]
Call Trace:
<IRQ>
[<ffffffffa01f2add>] ? sctp_bind_addr_copy+0x5d/0xe0 [sctp]
[<ffffffffa01e1fcb>] sctp_sf_do_5_1B_init+0x21b/0x340 [sctp]
[<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
[<ffffffffa01e5c09>] ? sctp_endpoint_lookup_assoc+0xc9/0xf0 [sctp]
[<ffffffffa01e61f6>] sctp_endpoint_bh_rcv+0x116/0x230 [sctp]
[<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
[<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
[<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
[<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[...]
A minimal way to address this is to check for NULL as we do on all
other such occasions where we know sctp_get_af_specific() could
possibly return with NULL.
Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/sctp/sm_make_chunk.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index ab734be8cb20..9f32741abb1c 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2609,6 +2609,9 @@ do_addr_param:
addr_param = param.v + sizeof(sctp_addip_param_t);
af = sctp_get_af_specific(param_type2af(param.p->type));
+ if (af == NULL)
+ break;
+
af->from_addr_param(&addr, addr_param,
htons(asoc->peer.port), 0);
--
1.9.3