| Message ID | 20180322062447.16537-1-yuchenlin@synology.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 03/22 14:24, yuchenlin@synology.com wrote: > From: yuchenlin <yuchenlin@synology.com> > > 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 <yuchenlin@synology.com> > --- > 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 <famz@redhat.com>
On 03/22/2018 02:41 AM, Fam Zheng wrote: > On Thu, 03/22 14:24, yuchenlin@synology.com wrote: >> From: yuchenlin <yuchenlin@synology.com> >> >> 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 <yuchenlin@synology.com> >> --- >> +++ 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) >> + Hmm, with sectors instead of bytes, you don't want to use Phillipe's '2 * T_BYTE' macro after all; but it would still look better spelled as '(1ULL << 32)' or '(4ULL * 1024 * 1024 * 1024)'. Most importantly, since the value does NOT fit in a 32-bit unsigned integer, I think you NEED to use the ULL suffix to make your intent clear. >> #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. Also, CC'ing qemu-block, as all block-related patches should go through there. > > Reviewed-by: Fam Zheng <famz@redhat.com> > > >
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;