Re: [Qemu-devel] [PATCH 4/4] qcow2: Fix leak of opts in qcow2_open

[Benoît Canet]

The Wednesday 27 Aug 2014 à 14:02:36 (+0800), Fam Zheng wrote :
> Not all the error paths release opts, fix it by moving it after the fail
> label.
> 
> Signed-off-by: Fam Zheng <address@hidden>
> ---
>  block/qcow2.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index f9e045f..b4c4a6e 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -535,7 +535,7 @@ static int qcow2_open(BlockDriverState *bs, QDict 
> *options, int flags,
>      unsigned int len, i;
>      int ret = 0;
>      QCowHeader header;
> -    QemuOpts *opts;
> +    QemuOpts *opts = NULL;
>      Error *local_err = NULL;
>      uint64_t ext_end;
>      uint64_t l1_vm_state_index;
> @@ -932,7 +932,6 @@ static int qcow2_open(BlockDriverState *bs, QDict 
> *options, int flags,
>          error_setg(errp, "Unsupported value '%s' for qcow2 option "
>                     "'overlap-check'. Allowed are either of the following: "
>                     "none, constant, cached, all", opt_overlap_check);
> -        qemu_opts_del(opts);
>          ret = -EINVAL;
>          goto fail;
>      }
> @@ -946,7 +945,6 @@ static int qcow2_open(BlockDriverState *bs, QDict 
> *options, int flags,
>                                overlap_check_template & (1 << i)) << i;
>      }
>  
> -    qemu_opts_del(opts);
>  
>      if (s->use_lazy_refcounts && s->qcow_version < 3) {
>          error_setg(errp, "Lazy refcounts require a qcow2 image with at least 
> "
> @@ -964,6 +962,7 @@ static int qcow2_open(BlockDriverState *bs, QDict 
> *options, int flags,


>      return ret;
The code is returning here in this case and the qemu_opts_del is hidden in the 
fail label.
Do we need to qemu_opts_del on success just before return like it was done 
before ?

>  
>   fail:
> +    qemu_opts_del(opts);
>      g_free(s->unknown_header_fields);
>      cleanup_unknown_header_ext(bs);
>      qcow2_free_snapshots(bs);
> -- 
> 2.1.0
> 
>