Commit a3548077 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Fix refcount table size calculation 



A missing factor for the refcount table entry size in the calculation
could mean that too little memory was allocated for the in-memory
representation of the table, resulting in a buffer overflow.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMichael Tokarev <mjt@tls.msk.ru>
Tested-by: default avatarMichael Tokarev <mjt@tls.msk.ru>
parent 8809e289

block/qcow2-refcount.c

+2 −1
Original line number Diff line number Diff line
@@ -301,7 +301,8 @@ static int alloc_refcount_block(BlockDriverState *bs, 
    uint64_t last_table_size;

    uint64_t blocks_clusters;

    do {

        uint64_t table_clusters = size_to_clusters(s, table_size);

        uint64_t table_clusters =

            size_to_clusters(s, table_size * sizeof(uint64_t));

        blocks_clusters = 1 +

            ((table_clusters + refcount_block_clusters - 1)

            / refcount_block_clusters);