block: update string sizes for filename,backing_file,exact_filename

The string field entries 'filename', 'backing_file', and
'exact_filename' in the BlockDriverState struct are defined as 1024
bytes.

However, many places that use these values accept a maximum of PATH_MAX
bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations.
This patch makes the BlockDriverStruct field string sizes match usage.

This patch also does a few fixes related to the size that needs to
happen now:

    * the block qapi driver is updated to use PATH_MAX bytes
    * the qcow and qcow2 drivers have an additional safety check
    * the block vvfat driver is updated to use PATH_MAX bytes
      for the size of backing_file, for systems where PATH_MAX is < 1024
      bytes.
    * qemu-img uses PATH_MAX rather than 1024.  These instances were not
      changed to be dynamically allocated, however, as the extra
      temporary 3K in stack usage for qemu-img does not seem worrisome.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Jeff Cody 2015-01-22 08:03:30 -05:00 committed by Kevin Wolf
parent 1d33936ea8
commit 9a29e18f7d
6 changed files with 13 additions and 12 deletions

View File

@ -210,10 +210,10 @@ void bdrv_query_image_info(BlockDriverState *bs,
backing_filename = bs->backing_file;
if (backing_filename[0] != '\0') {
char *backing_filename2 = g_malloc0(1024);
char *backing_filename2 = g_malloc0(PATH_MAX);
info->backing_filename = g_strdup(backing_filename);
info->has_backing_filename = true;
bdrv_get_full_backing_filename(bs, backing_filename2, 1024, &err);
bdrv_get_full_backing_filename(bs, backing_filename2, PATH_MAX, &err);
if (err) {
error_propagate(errp, err);
qapi_free_ImageInfo(info);

View File

@ -215,7 +215,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
/* read the backing file name */
if (header.backing_file_offset != 0) {
len = header.backing_file_size;
if (len > 1023) {
if (len > 1023 || len > sizeof(bs->backing_file)) {
error_setg(errp, "Backing file name too long");
ret = -EINVAL;
goto fail;

View File

@ -868,7 +868,8 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
/* read the backing file name */
if (header.backing_file_offset != 0) {
len = header.backing_file_size;
if (len > MIN(1023, s->cluster_size - header.backing_file_offset)) {
if (len > MIN(1023, s->cluster_size - header.backing_file_offset) ||
len > sizeof(bs->backing_file)) {
error_setg(errp, "Backing file name too long");
ret = -EINVAL;
goto fail;

View File

@ -2909,8 +2909,8 @@ static int enable_write_target(BDRVVVFATState *s, Error **errp)
array_init(&(s->commits), sizeof(commit_t));
s->qcow_filename = g_malloc(1024);
ret = get_tmp_filename(s->qcow_filename, 1024);
s->qcow_filename = g_malloc(PATH_MAX);
ret = get_tmp_filename(s->qcow_filename, PATH_MAX);
if (ret < 0) {
error_setg_errno(errp, -ret, "can't create temporary file");
goto err;

View File

@ -339,13 +339,13 @@ struct BlockDriverState {
* regarding this BDS's context */
QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
char filename[1024];
char backing_file[1024]; /* if non zero, the image is a diff of
char filename[PATH_MAX];
char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
this file image */
char backing_format[16]; /* if non-zero and backing_file exists */
QDict *full_open_options;
char exact_filename[1024];
char exact_filename[PATH_MAX];
BlockDriverState *backing_hd;
BlockDriverState *file;

View File

@ -2556,7 +2556,7 @@ static int img_rebase(int argc, char **argv)
/* For safe rebasing we need to compare old and new backing file */
if (!unsafe) {
char backing_name[1024];
char backing_name[PATH_MAX];
blk_old_backing = blk_new_with_bs("old_backing", &error_abort);
bs_old_backing = blk_bs(blk_old_backing);
@ -2614,7 +2614,7 @@ static int img_rebase(int argc, char **argv)
}
old_backing_num_sectors = bdrv_nb_sectors(bs_old_backing);
if (old_backing_num_sectors < 0) {
char backing_name[1024];
char backing_name[PATH_MAX];
bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
error_report("Could not get size of '%s': %s",