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Re: [Qemu-devel] [PATCH v2] vmdk: return ERROR when cluster sector is la
From: |
Fam Zheng |
Subject: |
Re: [Qemu-devel] [PATCH v2] vmdk: return ERROR when cluster sector is larger than vmdk limitation |
Date: |
Thu, 22 Mar 2018 15:41:29 +0800 |
User-agent: |
Mutt/1.9.2 (2017-12-15) |
On Thu, 03/22 14:24, address@hidden wrote:
> From: yuchenlin <address@hidden>
>
> VMDK has a hard limitation of extent size, which is due to the size of grain
> table entry is 32 bits. It means it can only point to a grain located at
> offset = 2^32. To avoid writing the user data beyond limitation and record a
> useless offset
> in grain table. We should return ERROR here.
>
> Signed-off-by: yuchenlin <address@hidden>
> ---
> v1->v2:
> - change commit message
> - check before allocating
> - should be >=
> - the unit is sector now
>
> thanks
>
> block/vmdk.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/block/vmdk.c b/block/vmdk.c
> index f94c49a9c0..a1c21dbbba 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -47,6 +47,8 @@
> #define VMDK4_FLAG_MARKER (1 << 17)
> #define VMDK4_GD_AT_END 0xffffffffffffffffULL
>
> +#define VMDK_EXTENT_MAX_SECTORS (4294967296)
> +
> #define VMDK_GTE_ZEROED 0x1
>
> /* VMDK internal error codes */
> @@ -1250,6 +1252,10 @@ static int get_cluster_offset(BlockDriverState *bs,
> return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
> }
>
> + if (extent->next_cluster_sector >= VMDK_EXTENT_MAX_SECTORS) {
> + return VMDK_ERROR;
> + }
> +
> cluster_sector = extent->next_cluster_sector;
> extent->next_cluster_sector += extent->cluster_sectors;
>
> --
> 2.16.2
>
Cc'ing Kevin and Max who merge block/ patches.
Reviewed-by: Fam Zheng <address@hidden>