1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2018 Oracle and/or its affiliates. All Rights Reserved.
3 *
4 * Regression test-case for the crash caused by over-sized SCTP chunk,
5 * fixed by upstream commit 07f2c7ab6f8d ("sctp: verify size of a new
6 * chunk in _sctp_make_chunk()")
7 */
8
9 #include <stdlib.h>
10 #include <unistd.h>
11 #include <sys/types.h>
12 #include <sys/socket.h>
13 #include <netinet/in.h>
14 #include <netinet/ip.h>
15 #include <netinet/ip6.h>
16 #include <netdb.h>
17 #include <sys/syscall.h>
18
19 #include "tst_test.h"
20 #include "tst_safe_stdio.h"
21 #include "tst_checksum.h"
22 #include "lapi/netinet_in.h"
23 #include "lapi/socket.h"
24 #include "lapi/sctp.h"
25
26 static int port;
27 static int sfd, cfd;
28 static struct sockaddr_in6 rmt, loc;
29
30 static uint8_t packet[IP_MAXPACKET];
31 static int pkt_len;
32 static char *addr_param;
33 static int addr_num = 3273;
34
setup_server(void)35 static void setup_server(void)
36 {
37 loc.sin6_family = AF_INET6;
38 loc.sin6_addr = in6addr_loopback;
39
40 sfd = SAFE_SOCKET(AF_INET6, SOCK_STREAM, IPPROTO_SCTP);
41 SAFE_BIND(sfd, (struct sockaddr *)&loc, sizeof(loc));
42
43 port = TST_GETSOCKPORT(sfd);
44 tst_res(TINFO, "sctp server listen on %d", port);
45
46 SAFE_LISTEN(sfd, 1);
47
48 srand(port);
49 }
50
update_packet_field(size_t * off,void * buf,size_t buf_len)51 static void update_packet_field(size_t *off, void *buf, size_t buf_len)
52 {
53 memcpy(packet + *off, buf, buf_len);
54 *off += buf_len;
55 }
56
setup_client(void)57 static void setup_client(void)
58 {
59 struct ip6_hdr ip6;
60 const size_t ip6_hdr_len = sizeof(ip6);
61 size_t cmn_hdr_off;
62 size_t off;
63 int i;
64
65 memset(&ip6, 0, sizeof(ip6));
66 ip6.ip6_flow = htonl(6 << 28 | 2 << 20);
67 ip6.ip6_hops = 64;
68 ip6.ip6_nxt = IPPROTO_SCTP;
69 ip6.ip6_src.s6_addr[15] = 1;
70 ip6.ip6_dst.s6_addr[15] = 1;
71 rmt.sin6_family = AF_INET6;
72 rmt.sin6_addr = in6addr_loopback;
73
74 /* SCTP common header */
75 off = ip6_hdr_len;
76
77 uint16_t src_port = htons(port - 1);
78 uint16_t dst_port = htons(port);
79 uint32_t vtag = 0;
80 uint32_t checksum = 0;
81
82 update_packet_field(&off, &src_port, 2);
83 update_packet_field(&off, &dst_port, 2);
84 update_packet_field(&off, &vtag, 4);
85 update_packet_field(&off, &checksum, 4);
86 cmn_hdr_off = off;
87
88 /* SCTP INIT chunk */
89 uint16_t chunk_len;
90
91 packet[off++] = 1;
92 packet[off++] = 0;
93 off += 2; /* chunk length, will be set in the end */
94
95 uint32_t init_tag = rand();
96 uint32_t rwnd = htonl(106496);
97 uint16_t outs = htons(10);
98 uint16_t ins = htons(65535);
99 uint32_t init_tsn = rand();
100
101 update_packet_field(&off, &init_tag, 4);
102 update_packet_field(&off, &rwnd, 4);
103 update_packet_field(&off, &outs, 2);
104 update_packet_field(&off, &ins, 2);
105 update_packet_field(&off, &init_tsn, 4);
106
107 /* SCTP optional parameter for IPv6 addresses */
108 uint16_t param_type = htons(6);
109 uint16_t param_len = htons(20);
110
111 /* IPv6(40) + SCTP_COMMON(12) + SCTP_CHUNK(20) + SCTP_OPT(65460)) */
112 for (i = 0; i < addr_num; ++i) {
113 update_packet_field(&off, ¶m_type, 2);
114 update_packet_field(&off, ¶m_len, 2);
115 packet[off + 15] = 1;
116 off += 16;
117 }
118 pkt_len = off;
119
120 tst_res(TINFO, "set chunk length %zu", pkt_len - cmn_hdr_off);
121 chunk_len = htons(pkt_len - cmn_hdr_off);
122 memcpy(packet + cmn_hdr_off + 2, &chunk_len, 2);
123
124 /* set checksum for SCTP: common header + INIT chunk */
125 uint32_t csum = tst_crc32c(packet + ip6_hdr_len, pkt_len - ip6_hdr_len);
126
127 memcpy(packet + ip6_hdr_len + 8, &csum, 4);
128
129 ip6.ip6_plen = htons(pkt_len - ip6_hdr_len);
130 memcpy(packet, &ip6, ip6_hdr_len);
131
132 cfd = SAFE_SOCKET(AF_INET6, SOCK_RAW, IPPROTO_RAW);
133 }
134
135 static const char mtu_path[] = "/sys/class/net/lo/mtu";
136 static const unsigned int max_mtu = 65535;
137 static unsigned int mtu;
138
setup(void)139 static void setup(void)
140 {
141 if (tst_parse_int(addr_param, &addr_num, 1, INT_MAX))
142 tst_brk(TBROK, "wrong address number '%s'", addr_param);
143
144 /* We don't fragment IPv6 packet here yet, check that MTU is 65535 */
145 SAFE_FILE_SCANF(mtu_path, "%d", &mtu);
146 if (mtu < max_mtu)
147 tst_brk(TCONF, "Test needs that 'lo' MTU has %d", max_mtu);
148
149 setup_server();
150 setup_client();
151 }
152
run(void)153 static void run(void)
154 {
155 int pid = SAFE_FORK();
156
157 if (!pid) {
158 struct sockaddr_in6 addr6;
159 socklen_t addr_size = sizeof(addr6);
160
161 if (accept(sfd, (struct sockaddr *)&addr6, &addr_size) < 0)
162 tst_brk(TBROK | TERRNO, "accept() failed");
163 exit(0);
164 }
165
166 SAFE_SENDTO(1, cfd, packet, pkt_len, 0, (struct sockaddr *)&rmt,
167 sizeof(rmt));
168
169 SAFE_KILL(pid, SIGKILL);
170 SAFE_WAITPID(pid, NULL, 0);
171
172 tst_res(TPASS, "test doesn't cause crash");
173 }
174
175 static struct tst_option options[] = {
176 {"a:", &addr_param, "-a number of additional IP address params"},
177 {NULL, NULL, NULL}
178 };
179
180 static struct tst_test test = {
181 .needs_root = 1,
182 .setup = setup,
183 .forks_child = 1,
184 .test_all = run,
185 .options = options,
186 .tags = (const struct tst_tag[]) {
187 {"CVE", "2018-5803"},
188 {"linux-git", "07f2c7ab6f8d"},
189 {}
190 }
191 };
192