From c9a442e45094e693da45f0e3d03746d68e4460ec Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Tue, 6 Mar 2018 18:14:08 +0200 Subject: qcow2: Check L1 table parameters in qcow2_expand_zero_clusters() This function iterates over all snapshots of a qcow2 file in order to expand all zero clusters, but it does not validate the snapshots' L1 tables first. We now have a function to take care of this, so let's use it. We can also take the opportunity to replace the sector-based bdrv_read() with bdrv_pread(). Cc: Eric Blake Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'block') diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 98908c4264..1aee726c6a 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -25,6 +25,7 @@ #include "qemu/osdep.h" #include +#include "qapi/error.h" #include "qemu-common.h" #include "block/block_int.h" #include "block/qcow2.h" @@ -2092,11 +2093,21 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, } for (i = 0; i < s->nb_snapshots; i++) { - int l1_sectors = DIV_ROUND_UP(s->snapshots[i].l1_size * - sizeof(uint64_t), BDRV_SECTOR_SIZE); + int l1_size2; + uint64_t *new_l1_table; + Error *local_err = NULL; + + ret = qcow2_validate_table(bs, s->snapshots[i].l1_table_offset, + s->snapshots[i].l1_size, sizeof(uint64_t), + QCOW_MAX_L1_SIZE, "Snapshot L1 table", + &local_err); + if (ret < 0) { + error_report_err(local_err); + goto fail; + } - uint64_t *new_l1_table = - g_try_realloc(l1_table, l1_sectors * BDRV_SECTOR_SIZE); + l1_size2 = s->snapshots[i].l1_size * sizeof(uint64_t); + new_l1_table = g_try_realloc(l1_table, l1_size2); if (!new_l1_table) { ret = -ENOMEM; @@ -2105,9 +2116,8 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, l1_table = new_l1_table; - ret = bdrv_read(bs->file, - s->snapshots[i].l1_table_offset / BDRV_SECTOR_SIZE, - (void *)l1_table, l1_sectors); + ret = bdrv_pread(bs->file, s->snapshots[i].l1_table_offset, + l1_table, l1_size2); if (ret < 0) { goto fail; } -- cgit v1.2.3