Revision 9c5a8433cee3f03ecd67de0046c41ed9b01d1993 authored by Eric Blake on 11 June 2018, 21:39:26 UTC, committed by Michael Roth on 21 June 2018, 01:45:07 UTC
Commit a290f085 exposed a latent bug in qemu-img map introduced during the conversion of block status to be byte-based. Earlier in commit 5e344dd8, the internal interface get_block_status() switched to take byte-based parameters, but still called a sector-based block layer function; as such, rounding was added in the lone caller to obey the contract. However, commit 237d78f8 changed get_block_status() to truly be byte-based, at which point rounding to sector boundaries can result in calling bdrv_block_status() with 'bytes == 0' (a coding error) when the boundary between data and a hole falls mid-sector (true for the past-EOF implicit hole present in POSIX files). Fix things by removing the rounding that is now no longer necessary. See also https://bugzilla.redhat.com/1589738 Fixes: 237d78f8 Reported-by: Dan Kenigsberg <danken@redhat.com> Reported-by: Nir Soffer <nsoffer@redhat.com> Reported-by: Maor Lipchuk <mlipchuk@redhat.com> CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> (cherry picked from commit e0b371ed5e2db079051139136fd0478728b6a58f) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
1 parent d8a919f
json-streamer.c
/*
* JSON streaming support
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qapi/qmp/json-lexer.h"
#include "qapi/qmp/json-streamer.h"
#define MAX_TOKEN_SIZE (64ULL << 20)
#define MAX_TOKEN_COUNT (2ULL << 20)
#define MAX_NESTING (1ULL << 10)
static void json_message_free_token(void *token, void *opaque)
{
g_free(token);
}
static void json_message_free_tokens(JSONMessageParser *parser)
{
if (parser->tokens) {
g_queue_foreach(parser->tokens, json_message_free_token, NULL);
g_queue_free(parser->tokens);
parser->tokens = NULL;
}
}
static void json_message_process_token(JSONLexer *lexer, GString *input,
JSONTokenType type, int x, int y)
{
JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
JSONToken *token;
GQueue *tokens;
switch (type) {
case JSON_LCURLY:
parser->brace_count++;
break;
case JSON_RCURLY:
parser->brace_count--;
break;
case JSON_LSQUARE:
parser->bracket_count++;
break;
case JSON_RSQUARE:
parser->bracket_count--;
break;
default:
break;
}
token = g_malloc(sizeof(JSONToken) + input->len + 1);
token->type = type;
memcpy(token->str, input->str, input->len);
token->str[input->len] = 0;
token->x = x;
token->y = y;
parser->token_size += input->len;
g_queue_push_tail(parser->tokens, token);
if (type == JSON_ERROR) {
goto out_emit_bad;
} else if (parser->brace_count < 0 ||
parser->bracket_count < 0 ||
(parser->brace_count == 0 &&
parser->bracket_count == 0)) {
goto out_emit;
} else if (parser->token_size > MAX_TOKEN_SIZE ||
g_queue_get_length(parser->tokens) > MAX_TOKEN_COUNT ||
parser->bracket_count + parser->brace_count > MAX_NESTING) {
/* Security consideration, we limit total memory allocated per object
* and the maximum recursion depth that a message can force.
*/
goto out_emit_bad;
}
return;
out_emit_bad:
/*
* Clear out token list and tell the parser to emit an error
* indication by passing it a NULL list
*/
json_message_free_tokens(parser);
out_emit:
/* send current list of tokens to parser and reset tokenizer */
parser->brace_count = 0;
parser->bracket_count = 0;
/* parser->emit takes ownership of parser->tokens. Remove our own
* reference to parser->tokens before handing it out to parser->emit.
*/
tokens = parser->tokens;
parser->tokens = g_queue_new();
parser->emit(parser, tokens);
parser->token_size = 0;
}
void json_message_parser_init(JSONMessageParser *parser,
void (*func)(JSONMessageParser *, GQueue *))
{
parser->emit = func;
parser->brace_count = 0;
parser->bracket_count = 0;
parser->tokens = g_queue_new();
parser->token_size = 0;
json_lexer_init(&parser->lexer, json_message_process_token);
}
int json_message_parser_feed(JSONMessageParser *parser,
const char *buffer, size_t size)
{
return json_lexer_feed(&parser->lexer, buffer, size);
}
int json_message_parser_flush(JSONMessageParser *parser)
{
return json_lexer_flush(&parser->lexer);
}
void json_message_parser_destroy(JSONMessageParser *parser)
{
json_lexer_destroy(&parser->lexer);
json_message_free_tokens(parser);
}
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