qcow2: Fix L1 allocation size in qcow2_snapshot_load_tmp() (CVE-2014-0145)

For the L1 table to loaded for an internal snapshot, the code allocated
only enough memory to hold the currently active L1 table. If the
snapshot's L1 table is actually larger than the current one, this leads
to a buffer overflow.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2014-03-26 13:06:05 +01:00 committed by Stefan Hajnoczi
parent 11b128f406
commit c05e4667be
3 changed files with 22 additions and 2 deletions

View file

@ -680,7 +680,7 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs,
sn = &s->snapshots[snapshot_index];
/* Allocate and read in the snapshot's L1 table */
new_l1_bytes = s->l1_size * sizeof(uint64_t);
new_l1_bytes = sn->l1_size * sizeof(uint64_t);
new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512));
ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table, new_l1_bytes);