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>
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strmap.h
#ifndef STRMAP_H
#define STRMAP_H
#include "hashmap.h"
struct mem_pool;
struct strmap {
struct hashmap map;
struct mem_pool *pool;
unsigned int strdup_strings:1;
};
struct strmap_entry {
struct hashmap_entry ent;
const char *key;
void *value;
/* strmap_entry may be allocated extra space to store the key at end */
};
int cmp_strmap_entry(const void *hashmap_cmp_fn_data,
const struct hashmap_entry *entry1,
const struct hashmap_entry *entry2,
const void *keydata);
#define STRMAP_INIT { \
.map = HASHMAP_INIT(cmp_strmap_entry, NULL), \
.strdup_strings = 1, \
}
#define STRINTMAP_INIT { \
.map = STRMAP_INIT, \
.default_value = 0, \
}
#define STRSET_INIT { .map = STRMAP_INIT }
/*
* Initialize the members of the strmap. Any keys added to the strmap will
* be strdup'ed with their memory managed by the strmap.
*/
void strmap_init(struct strmap *map);
/*
* Same as strmap_init, but for those who want to control the memory management
* carefully instead of using the default of strdup_strings=1 and pool=NULL.
*/
void strmap_init_with_options(struct strmap *map,
struct mem_pool *pool,
int strdup_strings);
/*
* Remove all entries from the map, releasing any allocated resources.
*/
void strmap_clear(struct strmap *map, int free_values);
/*
* Similar to strmap_clear() but leaves map->map->table allocated and
* pre-sized so that subsequent uses won't need as many rehashings.
*/
void strmap_partial_clear(struct strmap *map, int free_values);
/*
* Insert "str" into the map, pointing to "data".
*
* If an entry for "str" already exists, its data pointer is overwritten, and
* the original data pointer returned. Otherwise, returns NULL.
*/
void *strmap_put(struct strmap *map, const char *str, void *data);
/*
* Return the strmap_entry mapped by "str", or NULL if there is not such
* an item in map.
*/
struct strmap_entry *strmap_get_entry(struct strmap *map, const char *str);
/*
* Return the data pointer mapped by "str", or NULL if the entry does not
* exist.
*/
void *strmap_get(struct strmap *map, const char *str);
/*
* Return non-zero iff "str" is present in the map. This differs from
* strmap_get() in that it can distinguish entries with a NULL data pointer.
*/
int strmap_contains(struct strmap *map, const char *str);
/*
* Remove the given entry from the strmap. If the string isn't in the
* strmap, the map is not altered.
*/
void strmap_remove(struct strmap *map, const char *str, int free_value);
/*
* Return how many entries the strmap has.
*/
static inline unsigned int strmap_get_size(struct strmap *map)
{
return hashmap_get_size(&map->map);
}
/*
* Return whether the strmap is empty.
*/
static inline int strmap_empty(struct strmap *map)
{
return strmap_get_size(map) == 0;
}
/*
* iterate through @map using @iter, @var is a pointer to a type strmap_entry
*/
#define strmap_for_each_entry(mystrmap, iter, var) \
hashmap_for_each_entry(&(mystrmap)->map, iter, var, ent)
/*
* strintmap:
* A map of string -> int, typecasting the void* of strmap to an int.
*
* Primary differences:
* 1) Since the void* value is just an int in disguise, there is no value
* to free. (Thus one fewer argument to strintmap_clear)
* 2) strintmap_get() returns an int, or returns the default_value if the
* key is not found in the strintmap.
* 3) No strmap_put() equivalent; strintmap_set() and strintmap_incr()
* instead.
*/
struct strintmap {
struct strmap map;
int default_value;
};
#define strintmap_for_each_entry(mystrmap, iter, var) \
strmap_for_each_entry(&(mystrmap)->map, iter, var)
static inline void strintmap_init(struct strintmap *map, int default_value)
{
strmap_init(&map->map);
map->default_value = default_value;
}
static inline void strintmap_init_with_options(struct strintmap *map,
int default_value,
struct mem_pool *pool,
int strdup_strings)
{
strmap_init_with_options(&map->map, pool, strdup_strings);
map->default_value = default_value;
}
static inline void strintmap_clear(struct strintmap *map)
{
strmap_clear(&map->map, 0);
}
static inline void strintmap_partial_clear(struct strintmap *map)
{
strmap_partial_clear(&map->map, 0);
}
static inline int strintmap_contains(struct strintmap *map, const char *str)
{
return strmap_contains(&map->map, str);
}
static inline void strintmap_remove(struct strintmap *map, const char *str)
{
strmap_remove(&map->map, str, 0);
}
static inline int strintmap_empty(struct strintmap *map)
{
return strmap_empty(&map->map);
}
static inline unsigned int strintmap_get_size(struct strintmap *map)
{
return strmap_get_size(&map->map);
}
/*
* Returns the value for str in the map. If str isn't found in the map,
* the map's default_value is returned.
*/
static inline int strintmap_get(struct strintmap *map, const char *str)
{
struct strmap_entry *result = strmap_get_entry(&map->map, str);
if (!result)
return map->default_value;
return (intptr_t)result->value;
}
static inline void strintmap_set(struct strintmap *map, const char *str,
intptr_t v)
{
strmap_put(&map->map, str, (void *)v);
}
/*
* Increment the value for str by amt. If str isn't in the map, add it and
* set its value to default_value + amt.
*/
void strintmap_incr(struct strintmap *map, const char *str, intptr_t amt);
/*
* strset:
* A set of strings.
*
* Primary differences with strmap:
* 1) The value is always NULL, and ignored. As there is no value to free,
* there is one fewer argument to strset_clear
* 2) No strset_get() because there is no value.
* 3) No strset_put(); use strset_add() instead.
*/
struct strset {
struct strmap map;
};
#define strset_for_each_entry(mystrset, iter, var) \
strmap_for_each_entry(&(mystrset)->map, iter, var)
static inline void strset_init(struct strset *set)
{
strmap_init(&set->map);
}
static inline void strset_init_with_options(struct strset *set,
struct mem_pool *pool,
int strdup_strings)
{
strmap_init_with_options(&set->map, pool, strdup_strings);
}
static inline void strset_clear(struct strset *set)
{
strmap_clear(&set->map, 0);
}
static inline void strset_partial_clear(struct strset *set)
{
strmap_partial_clear(&set->map, 0);
}
static inline int strset_contains(struct strset *set, const char *str)
{
return strmap_contains(&set->map, str);
}
static inline void strset_remove(struct strset *set, const char *str)
{
strmap_remove(&set->map, str, 0);
}
static inline int strset_empty(struct strset *set)
{
return strmap_empty(&set->map);
}
static inline unsigned int strset_get_size(struct strset *set)
{
return strmap_get_size(&set->map);
}
/* Returns 1 if str is added to the set; returns 0 if str was already in set */
int strset_add(struct strset *set, const char *str);
#endif /* STRMAP_H */
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