found by valgrind. Command: ./qemu-img convert -f parallels -O qcow2 1.hds 1.img Invalid read of size 4 at 0x17D0EF: parallels_co_read (parallels.c:357) by 0x11FEE4: bdrv_aio_rw_vector (block.c:4640) by 0x11FFBF: bdrv_aio_readv_em (block.c:4652) by 0x11F55F: bdrv_co_readv_em (block.c:4862) by 0x123428: bdrv_aligned_preadv (block.c:3056) by 0x1239FA: bdrv_co_do_preadv (block.c:3162) by 0x125424: bdrv_rw_co_entry (block.c:2706) by 0x155DD9: coroutine_trampoline (coroutine-ucontext.c:118) by 0x6975B6F: ??? (in /lib/x86_64-linux-gnu/libc-2.19.so)
The problem is that s->catalog_bitmap is allocated/filled as gmalloc(s->catalog_size) thus index validity check must be inclusive, i.e. index >= s->catalog_size is invalid. Signed-off-by: Denis V. Lunev <d...@openvz.org> Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> CC: Jeff Cody <jc...@redhat.com> CC: Kevin Wolf <kw...@redhat.com> CC: Stefan Hajnoczi <stefa...@redhat.com> --- block/parallels.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/parallels.c b/block/parallels.c index 2a814f3..4f9cd8d 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -155,7 +155,7 @@ static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num) offset = sector_num % s->tracks; /* not allocated */ - if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0)) + if ((index >= s->catalog_size) || (s->catalog_bitmap[index] == 0)) return -1; return ((uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset) * 512; -- 1.9.1