diff options
| author | Max Reitz <mreitz@redhat.com> | 2014-10-16 15:25:56 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2014-10-23 15:34:02 +0200 |
| commit | a1391444fe1cfef14976458f3293a2c6945e725c (patch) | |
| tree | a66c7c2da73dbf2ef603487f5cf79240ad2ac9d3 /block | |
| parent | 925bb3238d498172e8ee9a57842320b1d1bfc3a5 (diff) | |
qcow2: Do not overflow when writing an L1 sector
While writing an L1 table sector, qcow2_write_l1_entry() copies the
respective range from s->l1_table to the local "buf" array. The size of
s->l1_table does not have to be a multiple of L1_ENTRIES_PER_SECTOR;
thus, limit the index which is used for copying all entries to the L1
size.
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-cluster.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index f7dd8c0985..4d888c785f 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -164,12 +164,14 @@ static int l2_load(BlockDriverState *bs, uint64_t l2_offset, int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index) { BDRVQcowState *s = bs->opaque; - uint64_t buf[L1_ENTRIES_PER_SECTOR]; + uint64_t buf[L1_ENTRIES_PER_SECTOR] = { 0 }; int l1_start_index; int i, ret; l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); - for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { + for (i = 0; i < L1_ENTRIES_PER_SECTOR && l1_start_index + i < s->l1_size; + i++) + { buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); } |