From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: [NETFILTER]: H.323 helper: fix use of uninitialized data Date: Fri, 28 Apr 2006 16:19:23 +0200 Message-ID: <4452246B.6090704@trash.net> Mime-Version: 1.0 Content-Type: text/plain; name="x2" Content-Transfer-Encoding: 7bit Cc: Netfilter Development Mailinglist Return-path: To: Jing Min Zhao Content-Disposition: inline; filename="x2" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org [NETFILTER]: H.323 helper: fix use of uninitialized data When a Choice element contains an unsupported choice no error is returned and parsing continues normally, but the choice value is not set and contains data from the last parsed message. This may in turn lead to parsing of more stale data and following crashes. Fixes a crash triggered by testcase 0003243 from the PROTOS c07-h2250v4 testsuite following random other testcases: CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00210646 (2.6.17-rc2 #3) EIP is at memmove+0x19/0x22 eax: d7be0307 ebx: d7be0307 ecx: e841fcf9 edx: d7be0307 esi: bfffffff edi: bfffffff ebp: da5eb980 esp: c0347e2c ds: 007b es: 007b ss: 0068 Process events/0 (pid: 4, threadinfo=c0347000 task=dff86a90) Stack: <0>00000006 c0347ea6 d7be0301 e09a6b2c 00000006 da5eb980 d7be003e d7be0052 c0347f6c e09a6d9c 00000006 c0347ea6 00000006 00000000 d7b9a548 00000000 c0347f6c d7b9a548 00000004 e0a1a119 0000028f 00000006 c0347ea6 00000006 Call Trace: [] mangle_contents+0x40/0xd8 [ip_nat] [] ip_nat_mangle_tcp_packet+0xa1/0x191 [ip_nat] [] set_addr+0x60/0x14d [ip_nat_h323] [] q931_help+0x2da/0x71a [ip_conntrack_h323] [] q931_help+0x30c/0x71a [ip_conntrack_h323] [] ip_conntrack_help+0x22/0x2f [ip_conntrack] [] nf_iterate+0x2e/0x5f [] xfrm4_output_finish+0x0/0x39f [] nf_hook_slow+0x42/0xb0 [] xfrm4_output_finish+0x0/0x39f [] xfrm4_output+0x3c/0x4e [] xfrm4_output_finish+0x0/0x39f [] ip_forward+0x1c2/0x1fa [] ip_rcv+0x388/0x3b5 [] netif_receive_skb+0x2bc/0x2ec [] process_backlog+0x6b/0xd0 [] net_rx_action+0x4b/0xb7 [] __do_softirq+0x35/0x7d [] do_softirq+0x38/0x3f Signed-off-by: Patrick McHardy --- commit 462f3ddd384045c731b3268a1b9c91c834a5a68a tree c32b3381fbfdb579e1a88f80b99a34a0a12aa060 parent 5074fd5f2344bc58355868c75c8abcd4145cde84 author Patrick McHardy Fri, 28 Apr 2006 15:56:05 +0200 committer Patrick McHardy Fri, 28 Apr 2006 15:56:05 +0200 net/ipv4/netfilter/ip_conntrack_helper_h323_asn1.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/netfilter/ip_conntrack_helper_h323_asn1.c b/net/ipv4/netfilter/ip_conntrack_helper_h323_asn1.c index 491cd9b..355a53a 100644 --- a/net/ipv4/netfilter/ip_conntrack_helper_h323_asn1.c +++ b/net/ipv4/netfilter/ip_conntrack_helper_h323_asn1.c @@ -703,6 +703,10 @@ int decode_choice(bitstr_t * bs, field_t type = get_bits(bs, f->sz); } + /* Write Type */ + if (base) + *(unsigned *) base = type; + /* Check Range */ if (type >= f->ub) { /* Newer version? */ BYTE_ALIGN(bs); @@ -712,10 +716,6 @@ int decode_choice(bitstr_t * bs, field_t return H323_ERROR_NONE; } - /* Write Type */ - if (base) - *(unsigned *) base = type; - /* Transfer to son level */ son = &f->fields[type]; if (son->attr & STOP) {