From 4d7c5f8335dad1aac9bf00704dab5409b9a9f4db Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 8 Oct 2024 17:47:08 +0100 Subject: [PATCH] block/vdi.c: Make SECTOR_SIZE constant 64-bits Make the VDI SECTOR_SIZE define be a 64-bit constant; this matches how we define BDRV_SECTOR_SIZE. The benefit is that it means that we don't need to carefully cast to 64-bits when doing operations like "n_sectors * SECTOR_SIZE" to avoid doing a 32x32->32 multiply, which might overflow, and which Coverity and other static analysers tend to warn about. The specific potential overflow Coverity is highlighting is the one at the end of vdi_co_pwritev() where we write out n_sectors sectors to the block map. This is very unlikely to actually overflow, since the block map has 4 bytes per block and the maximum number of blocks in the image must fit into a 32-bit integer. So this commit is not fixing a real-world bug. An inspection of all the places currently using SECTOR_SIZE in the file shows none which care about the change in its type, except for one call to error_setg() which needs the format string adjusting. Resolves: Coverity CID 1508076 Suggested-by: Kevin Wolf Message-ID: <20241008164708.2966400-5-peter.maydell@linaro.org> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/vdi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/vdi.c b/block/vdi.c index 149e15c831..26f7638f1f 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -87,7 +87,7 @@ /* Command line option for static images. */ #define BLOCK_OPT_STATIC "static" -#define SECTOR_SIZE 512 +#define SECTOR_SIZE 512ULL #define DEFAULT_CLUSTER_SIZE 1048576 /* Note: can't use 1 * MiB, because it's passed to stringify() */ @@ -442,7 +442,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } else if (header.sector_size != SECTOR_SIZE) { error_setg(errp, "unsupported VDI image (sector size %" PRIu32 - " is not %u)", header.sector_size, SECTOR_SIZE); + " is not %llu)", header.sector_size, SECTOR_SIZE); ret = -ENOTSUP; goto fail; } else if (header.block_size != DEFAULT_CLUSTER_SIZE) {