Re: [Qemu-devel] [PATCH] scsi: Don't check uninitialized local variable

[Peter Lieven <pl@kamp.de>]

Am 08.01.2018 um 04:09 schrieb Fam Zheng:
> After the out label there is a check on iTask.task but it is not
> initialized yet.
>
> Fixes: e38bc23454ef763deb4405ebdee6a1081aa00bc8
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>   block/iscsi.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 5c0a9e55b6..1cb8cc93c5 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -659,8 +659,7 @@ static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
>       int64_t ret;
>   
>       if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
> -        ret = -EINVAL;
> -        goto out;
> +        return -EINVAL;
>       }
>   
>       /* default to all sectors allocated */

If lbpme is 0 we run into the same error. And this is even more likely than an unaligned request.

I think the right patch is to move the init of iTask up again where it was:


diff --git a/block/iscsi.c b/block/iscsi.c
index 5c0a9e5..6a1c537 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -658,6 +658,8 @@ static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
      uint64_t lba;
      int64_t ret;

+    iscsi_co_init_iscsitask(iscsilun, &iTask);
+
      if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
          ret = -EINVAL;
          goto out;
@@ -675,7 +677,6 @@ static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,

      lba = sector_qemu2lun(sector_num, iscsilun);

-    iscsi_co_init_iscsitask(iscsilun, &iTask);
      qemu_mutex_lock(&iscsilun->mutex);
  retry:
      if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,


Peter




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Peter Lieven

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