From a67e128a4f40cf07abd86f92d0d3c913db2ad885 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 20 May 2014 13:55:50 +0200 Subject: [PATCH] vhdx: Handle failure for potentially large allocations Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses the allocations in the vhdx block driver. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Reviewed-by: Benoit Canet --- block/vhdx-log.c | 7 ++++++- block/vhdx.c | 13 +++++++++++-- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/block/vhdx-log.c b/block/vhdx-log.c index 0088be8747..eb5c7a097b 100644 --- a/block/vhdx-log.c +++ b/block/vhdx-log.c @@ -352,7 +352,12 @@ static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s, } desc_sectors = vhdx_compute_desc_sectors(hdr.descriptor_count); - desc_entries = qemu_blockalign(bs, desc_sectors * VHDX_LOG_SECTOR_SIZE); + desc_entries = qemu_try_blockalign(bs->file, + desc_sectors * VHDX_LOG_SECTOR_SIZE); + if (desc_entries == NULL) { + ret = -ENOMEM; + goto exit; + } ret = vhdx_log_read_sectors(bs, log, §ors_read, desc_entries, desc_sectors, false); diff --git a/block/vhdx.c b/block/vhdx.c index febce21f82..f666940db7 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -958,7 +958,12 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, } /* s->bat is freed in vhdx_close() */ - s->bat = qemu_blockalign(bs, s->bat_rt.length); + s->bat = qemu_try_blockalign(bs->file, s->bat_rt.length); + if (s->bat == NULL) { + ret = -ENOMEM; + goto fail; + } + ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); if (ret < 0) { goto fail; @@ -1587,7 +1592,11 @@ static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s, use_zero_blocks || bdrv_has_zero_init(bs) == 0) { /* for a fixed file, the default BAT entry is not zero */ - s->bat = g_malloc0(length); + s->bat = g_try_malloc0(length); + if (length && s->bat != NULL) { + ret = -ENOMEM; + goto exit; + } block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : PAYLOAD_BLOCK_NOT_PRESENT; block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;