Revision b3118bdc91876cbc04b7e81dcf7bea71d86ce4f8 authored by Shawn O. Pearce on 14 October 2009, 14:23:51 UTC, committed by Junio C Hamano on 14 October 2009, 20:39:37 UTC
Some types of corruption to a pack may confuse the deflate stream which stores an object. In Andy's reported case a 36 byte region of the pack was overwritten, leading to what appeared to be a valid deflate stream that was trying to produce a result larger than our allocated output buffer could accept. Z_BUF_ERROR is returned from inflate() if either the input buffer needs more input bytes, or the output buffer has run out of space. Previously we only considered the former case, as it meant we needed to move the stream's input buffer to the next window in the pack. We now abort the loop if inflate() returns Z_BUF_ERROR without consuming the entire input buffer it was given, or has filled the entire output buffer but has not yet returned Z_STREAM_END. Either state is a clear indicator that this loop is not working as expected, and should not continue. This problem cannot occur with loose objects as we open the entire loose object as a single buffer and treat Z_BUF_ERROR as an error. Reported-by: Andy Isaacson <adi@hexapodia.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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hash.c
/*
* Some generic hashing helpers.
*/
#include "cache.h"
#include "hash.h"
/*
* Look up a hash entry in the hash table. Return the pointer to
* the existing entry, or the empty slot if none existed. The caller
* can then look at the (*ptr) to see whether it existed or not.
*/
static struct hash_table_entry *lookup_hash_entry(unsigned int hash, const struct hash_table *table)
{
unsigned int size = table->size, nr = hash % size;
struct hash_table_entry *array = table->array;
while (array[nr].ptr) {
if (array[nr].hash == hash)
break;
nr++;
if (nr >= size)
nr = 0;
}
return array + nr;
}
/*
* Insert a new hash entry pointer into the table.
*
* If that hash entry already existed, return the pointer to
* the existing entry (and the caller can create a list of the
* pointers or do anything else). If it didn't exist, return
* NULL (and the caller knows the pointer has been inserted).
*/
static void **insert_hash_entry(unsigned int hash, void *ptr, struct hash_table *table)
{
struct hash_table_entry *entry = lookup_hash_entry(hash, table);
if (!entry->ptr) {
entry->ptr = ptr;
entry->hash = hash;
table->nr++;
return NULL;
}
return &entry->ptr;
}
static void grow_hash_table(struct hash_table *table)
{
unsigned int i;
unsigned int old_size = table->size, new_size;
struct hash_table_entry *old_array = table->array, *new_array;
new_size = alloc_nr(old_size);
new_array = xcalloc(sizeof(struct hash_table_entry), new_size);
table->size = new_size;
table->array = new_array;
table->nr = 0;
for (i = 0; i < old_size; i++) {
unsigned int hash = old_array[i].hash;
void *ptr = old_array[i].ptr;
if (ptr)
insert_hash_entry(hash, ptr, table);
}
free(old_array);
}
void *lookup_hash(unsigned int hash, const struct hash_table *table)
{
if (!table->array)
return NULL;
return lookup_hash_entry(hash, table)->ptr;
}
void **insert_hash(unsigned int hash, void *ptr, struct hash_table *table)
{
unsigned int nr = table->nr;
if (nr >= table->size/2)
grow_hash_table(table);
return insert_hash_entry(hash, ptr, table);
}
int for_each_hash(const struct hash_table *table, int (*fn)(void *))
{
int sum = 0;
unsigned int i;
unsigned int size = table->size;
struct hash_table_entry *array = table->array;
for (i = 0; i < size; i++) {
void *ptr = array->ptr;
array++;
if (ptr) {
int val = fn(ptr);
if (val < 0)
return val;
sum += val;
}
}
return sum;
}
void free_hash(struct hash_table *table)
{
free(table->array);
table->array = NULL;
table->size = 0;
table->nr = 0;
}
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