2.6.32 2013 local root ~ mr.hawqal

5/17/2018 2.6.32 2013 Local RoOt ~ Mr.HaWQaL

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===============================================Linux Kernel 2.6.32 Local Root Exploit (x86_64)| Mr.HaWQaL | ~ | sEc4Ever|===============================================

#define _GNU_SOURCE

#include #include

#include #include

#define KSYM_NAME_LEN 127

struct sym_entry {unsigned long long addr;unsigned int len;unsigned char *sym;

};

static struct sym_entry *table;static unsigned int table_size, table_cnt;static unsigned long long _text, _stext, _etext, _sinittext, _einittext, _***tratext, _eextratext;static int all_symbols = 0;static char symbol_prefix_char = '\0';

int token_profit[0x10000];

/* the table that holds the result of the compression */unsigned char best_table[256][2];unsigned char best_table_len[256];

static void usage(void){

fprintf(stderr, "Usage: kallsyms [--all-symbols] [--symbol-prefix=] < in.map > out.S\n");

exit(1);}

/** This ignores the intensely annoying "mapping symbols" found* in ARM ELF files: $a, $t and $d.*/static inline int is_arm_mapping_symbol(const char *str)

{return str[0] == '$' && strchr("atd", str[1]) && (str[2] == '\0' || str[2] == '.');

}

static int read_symbol(FILE *in, struct sym_entry *s){

char str[500];char *sym, stype;int rc;


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rc = fscanf(in, "%llx %c %499s\n", &s->addr, &stype, str);if (rc != 3) {

if (rc != EOF) {/* skip line */fgets(str, 500, in);

}return -1;

}

sym = str;

/* skip prefix char */if (symbol_prefix_char && str[0] == symbol_prefix_char)sym++;

/* Ignore most absolute/undefined (?) symbols. */if (strcmp(sym, "_text") == 0)

_text = s->addr;else if (strcmp(sym, "_stext") == 0)

_stext = s->addr;else if (strcmp(sym, "_etext") == 0)

_etext = s->addr;else if (strcmp(sym, "_sinittext") == 0)

_sinittext = s->addr;

else if (strcmp(sym, "_einittext") == 0)_einittext = s->addr;else if (strcmp(sym, "_***tratext") == 0)

_***tratext = s->addr;else if (strcmp(sym, "_eextratext") == 0)

_eextratext = s->addr;else if (toupper(stype) == 'A'){

/* Keep these useful absolute symbols */if (strcmp(sym, "__kernel_syscall_via_break") && strcmp(sym, "__kernel_syscall_via_epc") && strcmp(sym, "__kernel_sigtramp") && strcmp(sym, "__gp"))

return -1;

}else if (toupper(stype) == 'U' ||

is_arm_mapping_symbol(sym))return -1;

/* exclude also MIPS ELF local symbols ($L123 instead of .L123) */else if (str[0] == '$')

return -1;

/* include the type field in the symbol name, so that it gets* compressed together */s->len = strlen(str) + 1;

s->sym = malloc(s->len + 1);if (!s->sym) {

fprintf(stderr, "kallsyms failure: ""unable to allocate required amount of memory\n");

exit(EXIT_FAILURE);}strcpy((char *)s->sym + 1, str);s->sym[0] = stype;

return 0;


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}

static int symbol_valid(struct sym_entry *s){

/* Symbols which vary between passes. Passes 1 and 2 must have* identical symbol lists. The kallsyms_* symbols below are only added* after pass 1, they would be included in pass 2 when --all-symbols is* specified so exclude them to get a stable symbol list.*/static char *special_symbols[] = {

"kallsyms_addresses",

"kallsyms_num_syms","kallsyms_names","kallsyms_markers","kallsyms_token_table","kallsyms_token_index",

/* Exclude linker generated symbols which vary between passes */"_SDA_BASE_", /* ppc */"_SDA2_BASE_", /* ppc */NULL };

int i;int offset = 1;

/* skip prefix char */if (symbol_prefix_char && *(s->sym + 1) == symbol_prefix_char)offset++;

/* if --all-symbols is not specified, then symbols outside the text* and inittext sections are discarded */if (!all_symbols) {

if ((s->addr < _stext || s->addr > _etext) && (s->addr < _sinittext || s->addr > _einittext) && (s->addr < _***tratext || s->addr > _eextratext))

return 0;/* Corner case. Discard any symbols with the same value as* _etext _einittext or _eextratext; they can move between pass

* 1 and 2 when the kallsyms data are added. If these symbols* move then they may get dropped in pass 2, which breaks the* kallsyms rules.*/if ((s->addr == _etext && strcmp((char*)s->sym + offset, "_etext

")) || (s->addr == _einittext && strcmp((char*)s->sym + offset, "_e

inittext")) || (s->addr == _eextratext && strcmp((char*)s->sym + offset, "_

eextratext")))return 0;

}

/* Exclude symbols which vary between passes. */if (strstr((char *)s->sym + offset, "_compiled."))

return 0;

for (i = 0; special_symbols[i]; i++)if( strcmp((char *)s->sym + offset, special_symbols[i]) == 0 )

return 0;

return 1;}


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static void read_map(FILE *in){

while (!feof(in)) {if (table_cnt >= table_size) {

table_size += 10000;table = realloc(table, sizeof(*table) * table_size);if (!table) {

fprintf(stderr, "out of memory\n");exit (1);

}

}if (read_symbol(in, &table[table_cnt]) == 0)table_cnt++;

}}

static void output_label(char *label){

if (symbol_prefix_char)printf(".globl %c%s\n", symbol_prefix_char, label);

elseprintf(".globl %s\n", label);

printf("\tALGN\n");

if (symbol_prefix_char)printf("%c%s:\n", symbol_prefix_char, label);else

printf("%s:\n", label);}

/* uncompress a compressed symbol. When this function is called, the best table* might still be compressed itself, so the function needs to be recursive */static int expand_symbol(unsigned char *data, int len, char *result){

int c, rlen, total=0;

while (len) {

c = *data;/* if the table holds a single char that is the same as the one* we are looking for, then end the search */if (best_table[c][0]==c && best_table_len[c]==1) {

*result++ = c;total++;

} else {/* if not, recurse and expand */rlen = expand_symbol(best_table[c], best_table_len[c], r

esult);total += rlen;result += rlen;

}

data++;len--;

}*result=0;

return total;}

static void write_src(void){


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unsigned int i, k, off;unsigned int best_idx[256];unsigned int *markers;char buf[KSYM_NAME_LEN+1];

printf("#include \n");printf("#if BITS_PER_LONG == 64\n");printf("#define PTR .quad\n");printf("#define ALGN .align 8\n");printf("#else\n");printf("#define PTR .long\n");

printf("#define ALGN .align 4\n");printf("#endif\n");

printf(".data\n");

/* Provide proper symbols relocatability by their '_text'* relativeness. The symbol names cannot be used to construct* normal symbol references as the list of symbols contains* symbols that are declared static and are private to their* .o files. This prevents .tmp_kallsyms.o or any other* object from referencing them.*/output_label("kallsyms_addresses");

for (i = 0; i < table_cnt; i++) {if (toupper(table[i].sym[0]) != 'A') {printf("\tPTR\t_text + %#llx\n",

table[i].addr - _text);} else {

printf("\tPTR\t%#llx\n", table[i].addr);}

}printf("\n");

output_label("kallsyms_num_syms");printf("\tPTR\t%d\n", table_cnt);printf("\n");

/* table of offset markers, that give the offset in the compressed stream

* every 256 symbols */markers = malloc(sizeof(unsigned int) * ((table_cnt + 255) / 256));if (!markers) {

fprintf(stderr, "kallsyms failure: ""unable to allocate required memory\n");

exit(EXIT_FAILURE);}

output_label("kallsyms_names");off = 0;

for (i = 0; i < table_cnt; i++) {if ((i & 0xFF) == 0)

markers[i >> 8] = off;

printf("\t.byte 0x%02x", table[i].len);for (k = 0; k < table[i].len; k++)

printf(", 0x%02x", table[i].sym[k]);printf("\n");

off += table[i].len + 1;


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}printf("\n");

output_label("kallsyms_markers");for (i = 0; i < ((table_cnt + 255) >> 8); i++)

printf("\tPTR\t%d\n", markers[i]);printf("\n");

free(markers);

output_label("kallsyms_token_table");

off = 0;for (i = 0; i < 256; i++) {best_idx[i] = off;expand_symbol(best_table[i], best_table_len[i], buf);printf("\t.asciz\t\"%s\"\n", buf);off += strlen(buf) + 1;

}printf("\n");

output_label("kallsyms_token_index");for (i = 0; i < 256; i++)

printf("\t.short\t%d\n", best_idx[i]);printf("\n");

}

/* table lookup compression functions */

/* count all the possible tokens in a symbol */static void learn_symbol(unsigned char *symbol, int len){

int i;

for (i = 0; i < len - 1; i++)token_profit[ symbol[i] + (symbol[i + 1]


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}}table_cnt = pos;

}

/* replace a given token in all the valid symbols. Use the sampled symbols* to update the counts */static void compress_symbols(unsigned char *str, int idx){

unsigned int i, len, size;unsigned char *p1, *p2;

for (i = 0; i < table_cnt; i++) {

len = table[i].len;p1 = table[i].sym;

/* find the token on the symbol */p2 = memmem(p1, len, str, 2);if (!p2) continue;

/* decrease the counts for this symbol's tokens */forget_symbol(table[i].sym, len);

size = len;

do {*p2 = idx;p2++;size -= (p2 - p1);memmove(p2, p2 + 1, size);p1 = p2;len--;

if (size < 2) break;

/* find the token on the symbol */

p2 = memmem(p1, size, str, 2);

} while (p2);

table[i].len = len;

/* increase the counts for this symbol's new tokens */learn_symbol(table[i].sym, len);

}}

/* search the token with the maximum profit */static int find_best_token(void)

{int i, best, bestprofit;

bestprofit=-10000;best = 0;

for (i = 0; i < 0x10000; i++) {if (token_profit[i] > bestprofit) {

best = i;bestprofit = token_profit[i];


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}}return best;

}

/* this is the core of the algorithm: calculate the "best" table */static void optimize_result(void){

int i, best;

/* using the '\0' symbol last allows compress_symbols to use standard

* fast string functions */for (i = 255; i >= 0; i--) {

/* if this table slot is empty (it is not used by an actual* original char code */if (!best_table_len[i]) {

/* find the token with the breates profit value */best = find_best_token();

/* place it in the "best" table */best_table_len[i] = 2;best_table[i][0] = best & 0xFF;

best_table[i][1] = (best >> 8) & 0xFF;

/* replace this token in all the valid symbols */compress_symbols(best_table[i], i);

}}

}

/* start by placing the symbols that are actually used on the table */static void insert_real_symbols_in_table(void){

unsigned int i, j, c;

memset(best_table, 0, sizeof(best_table));memset(best_table_len, 0, sizeof(best_table_len));

for (i = 0; i < table_cnt; i++) {for (j = 0; j < table[i].len; j++) {

c = table[i].sym[j];best_table[c][0]=c;best_table_len[c]=1;

}}

}

static void optimize_token_table(void)

{build_initial_tok_table();

insert_real_symbols_in_table();

/* When valid symbol is not registered, exit to error */if (!table_cnt) {

fprintf(stderr, "No valid symbol.\n");exit(1);

}


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optimize_result();}

int main(int argc, char **argv){

if (argc >= 2) {int i;for (i = 1; i < argc; i++) {

if(strcmp(argv[i], "--all-symbols") == 0)

all_symbols = 1;else if (strncmp(argv[i], "--symbol-prefix=", 16) == 0){

char *p = &argv[i][16];/* skip quote */if ((*p == '"' && *(p+2) == '"') || (*p == '\''

&& *(p+2) == '\''))p++;

symbol_prefix_char = *p;} else

usage();}

} else if (argc != 1)

usage();

read_map(stdin);optimize_token_table();write_src();

return 0;}

2.6.32 2013 local root ~ mr.hawqal

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