Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC
The `struct attr_stack` tracks the stack of all patterns together with their attributes. When parsing a gitattributes file that has more than 2^31 such patterns though we may trigger multiple out-of-bounds reads on 64 bit platforms. This is because while the `num_matches` variable is an unsigned integer, we always use a signed integer to iterate over them. I have not been able to reproduce this issue due to memory constraints on my systems. But despite the out-of-bounds reads, the worst thing that can seemingly happen is to call free(3P) with a garbage pointer when calling `attr_stack_free()`. Fix this bug by using unsigned integers to iterate over the array. While this makes the iteration somewhat awkward when iterating in reverse, it is at least better than knowingly running into an out-of-bounds read. While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
hex.c
#include "cache.h"
const signed char hexval_table[256] = {
-1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
-1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
-1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
-1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
-1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
-1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
-1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
-1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
-1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
};
int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
{
for (; len; len--, hex += 2) {
unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
if (val & ~0xff)
return -1;
*binary++ = val;
}
return 0;
}
static int get_hash_hex_algop(const char *hex, unsigned char *hash,
const struct git_hash_algo *algop)
{
int i;
for (i = 0; i < algop->rawsz; i++) {
int val = hex2chr(hex);
if (val < 0)
return -1;
*hash++ = val;
hex += 2;
}
return 0;
}
int get_sha1_hex(const char *hex, unsigned char *sha1)
{
return get_hash_hex_algop(hex, sha1, the_hash_algo);
}
int get_oid_hex_algop(const char *hex, struct object_id *oid,
const struct git_hash_algo *algop)
{
return get_hash_hex_algop(hex, oid->hash, algop);
}
/*
* NOTE: This function relies on hash algorithms being in order from shortest
* length to longest length.
*/
int get_oid_hex_any(const char *hex, struct object_id *oid)
{
int i;
for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
if (!get_hash_hex_algop(hex, oid->hash, &hash_algos[i]))
return i;
}
return GIT_HASH_UNKNOWN;
}
int get_oid_hex(const char *hex, struct object_id *oid)
{
return get_oid_hex_algop(hex, oid, the_hash_algo);
}
int parse_oid_hex_algop(const char *hex, struct object_id *oid,
const char **end,
const struct git_hash_algo *algop)
{
int ret = get_hash_hex_algop(hex, oid->hash, algop);
if (!ret)
*end = hex + algop->hexsz;
return ret;
}
int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end)
{
int ret = get_oid_hex_any(hex, oid);
if (ret)
*end = hex + hash_algos[ret].hexsz;
return ret;
}
int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
return parse_oid_hex_algop(hex, oid, end, the_hash_algo);
}
char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
const struct git_hash_algo *algop)
{
static const char hex[] = "0123456789abcdef";
char *buf = buffer;
int i;
for (i = 0; i < algop->rawsz; i++) {
unsigned int val = *hash++;
*buf++ = hex[val >> 4];
*buf++ = hex[val & 0xf];
}
*buf = '\0';
return buffer;
}
char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
}
char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
{
static int bufno;
static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
}
char *hash_to_hex(const unsigned char *hash)
{
return hash_to_hex_algop(hash, the_hash_algo);
}
char *oid_to_hex(const struct object_id *oid)
{
return hash_to_hex_algop(oid->hash, the_hash_algo);
}
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