Change the types of variables in allocate_clusters() to int64_t so we do
not have to worry about potential overflows.
Add an assertion that our accesses to s->bat[] do not result in a buffer
overflow and that the implicit conversion performed when invoking
bat_entry_off() does not result in an integer overflow.
Coverity-id:
1307776
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id:
20170331170512.10381-1-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
int nb_sectors, int *pnum)
{
BDRVParallelsState *s = bs->opaque;
int nb_sectors, int *pnum)
{
BDRVParallelsState *s = bs->opaque;
- uint32_t idx, to_allocate, i;
- int64_t pos, space;
+ int64_t pos, space, idx, to_allocate, i;
pos = block_status(s, sector_num, nb_sectors, pnum);
if (pos > 0) {
pos = block_status(s, sector_num, nb_sectors, pnum);
if (pos > 0) {
}
idx = sector_num / s->tracks;
}
idx = sector_num / s->tracks;
- if (idx >= s->bat_size) {
- return -EINVAL;
- }
-
to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
+
+ /* This function is called only by parallels_co_writev(), which will never
+ * pass a sector_num at or beyond the end of the image (because the block
+ * layer never passes such a sector_num to that function). Therefore, idx
+ * is always below s->bat_size.
+ * block_status() will limit *pnum so that sector_num + *pnum will not
+ * exceed the image end. Therefore, idx + to_allocate cannot exceed
+ * s->bat_size.
+ * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
+ * will always fit into a uint32_t. */
+ assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
+
space = to_allocate * s->tracks;
if (s->data_end + space > bdrv_getlength(bs->file->bs) >> BDRV_SECTOR_BITS) {
int ret;
space = to_allocate * s->tracks;
if (s->data_end + space > bdrv_getlength(bs->file->bs) >> BDRV_SECTOR_BITS) {
int ret;