1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/* scan3.c - scan all writable memory of a process for qwords equal to any
of the given 64-bit needles; print every hit address.
usage: scan3 PID 0xNEEDLE [0xNEEDLE ...] */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#define MAXR 4096
#define MAXN 64
static struct { uint64_t lo, hi; } wr[MAXR];
static int nwr;
static uint64_t needle[MAXN];
static int nn;
static void load_maps(int pid)
{
char path[64], line[1024];
snprintf(path, sizeof path, "/proc/%d/maps", pid);
FILE *f = fopen(path, "r");
if (!f) { perror("maps"); exit(1); }
while (fgets(line, sizeof line, f)) {
uint64_t lo, hi;
char perms[16];
if (sscanf(line, "%lx-%lx %15s", &lo, &hi, perms) < 3) continue;
if (strchr(perms, 'w') && nwr < MAXR) { wr[nwr].lo = lo; wr[nwr].hi = hi; nwr++; }
}
fclose(f);
}
int main(int argc, char **argv)
{
if (argc < 3) { fprintf(stderr, "usage: scan3 PID 0xNEEDLE [...]\n"); return 1; }
int pid = atoi(argv[1]);
for (int i = 2; i < argc && nn < MAXN; i++)
needle[nn++] = strtoull(argv[i], 0, 16);
load_maps(pid);
printf("writable=%d needles=%d\n", nwr, nn);
char mp[64];
snprintf(mp, sizeof mp, "/proc/%d/mem", pid);
int fd = open(mp, O_RDONLY);
if (fd < 0) { perror("mem"); return 1; }
size_t CH = 4 << 20;
uint8_t *buf = malloc(CH + 64);
int hits = 0;
for (int r = 0; r < nwr; r++) {
uint64_t a = wr[r].lo;
while (a < wr[r].hi) {
size_t n = (size_t)((wr[r].hi - a) < CH ? (wr[r].hi - a) : CH);
ssize_t got = pread(fd, buf, n, (off_t)a);
if (got <= 0) {
if (n > (256u << 10)) { n = 256u << 10; continue; }
a += 4096; continue;
}
if ((size_t)got < n) n = got;
n -= n % 8;
uint64_t *w = (uint64_t *)buf;
for (size_t i = 0; i < n / 8; i++) {
uint64_t v = w[i];
for (int k = 0; k < nn; k++) {
if (v == needle[k]) {
printf("hit 0x%lx = 0x%lx\n", a + i * 8, v);
hits++;
}
}
}
a += n;
}
}
printf("hits=%d\n", hits);
return 0;
}
|
