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Date: Mon, 10 Oct 2016 13:28:33 +0200
From: Greg Kurz <groug@kaod.org>
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Subject: Re: [Qemu-devel] [PATCH] 9pfs: fix memory leak in v9fs_xattrcreate
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To: Li Qiang <liq3ea@gmail.com>
Cc: qemu-devel@nongnu.org, Li Qiang <liqiang6-s@360.cn>

On Mon, 10 Oct 2016 13:20:51 +0200
Greg Kurz <groug@kaod.org> wrote:

> On Mon, 10 Oct 2016 03:41:38 -0700
> Li Qiang <liq3ea@gmail.com> wrote:
> 
> > From: Li Qiang <liqiang6-s@360.cn>
> > 
> > The 'fs.xattr.value' field in V9fsFidState object doesn't consider the
> > situation that this field has been allocated previously. Every time, it
> > will be allocated directly. This leads a host memory leak issue. This
> > patch fix this.
> > 
> > Signed-off-by: Li Qiang <liqiang6-s@360.cn>
> > ---  
> 
> I'll add to the changelog that this may happen if the client sends a
> Txattrcreate message with the same fid number before the fid was
> clunked.
> 
> Reviewed-by: Greg Kurz <groug@kaod.org>
> 

Oops I may have answered to fast... what about xattr_fidp->fs.xattr.name ?
It looks like it is leaked the same way...

> >  hw/9pfs/9p.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> > index 8751c19..e4040dc 100644
> > --- a/hw/9pfs/9p.c
> > +++ b/hw/9pfs/9p.c
> > @@ -3282,6 +3282,7 @@ static void v9fs_xattrcreate(void *opaque)
> >      xattr_fidp->fs.xattr.flags = flags;
> >      v9fs_string_init(&xattr_fidp->fs.xattr.name);
> >      v9fs_string_copy(&xattr_fidp->fs.xattr.name, &name);
> > +    g_free(xattr_fidp->fs.xattr.value);
> >      xattr_fidp->fs.xattr.value = g_malloc0(size);
> >      err = offset;
> >      put_fid(pdu, file_fidp);  
>