From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43140) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ez0MZ-00064u-Jf for qemu-devel@nongnu.org; Thu, 22 Mar 2018 09:34:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ez0MY-0006ml-Os for qemu-devel@nongnu.org; Thu, 22 Mar 2018 09:34:39 -0400 From: yuchenlin@synology.com Date: Thu, 22 Mar 2018 21:33:37 +0800 Message-Id: <20180322133337.28024-1-yuchenlin@synology.com> Subject: [Qemu-devel] [PATCH v3] vmdk: return ERROR when cluster sector is larger than vmdk limitation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: famz@redhat.com, kwolf@redhat.com, mreitz@redhat.com, qemu-block@nongnu.org, eblake@redhat.com, yuchenlin From: yuchenlin 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 --- v2->v3: - use (1ULL << 32) to clearly show the limitation of offset is 2^32. thanks block/vmdk.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/block/vmdk.c b/block/vmdk.c index f94c49a9c0..84f8bbe480 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 (1ULL << 32) + #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