On Thu, May 6, 2021 at 4:57 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> On Thu, May 06, 2021 at 04:22:10PM +0200, Uladzislau Rezki wrote:
> > Seems like vmalloc() is called with zero size passed:
> >
> > <snip>
> > void *__vmalloc_node_range(unsigned long size, unsigned long align,
> > unsigned long start, unsigned long end, gfp_t gfp_mask,
> > pgprot_t prot, unsigned long vm_flags, int node,
> > const void *caller)
> > {
> > struct vm_struct *area;
> > void *addr;
> > unsigned long real_size = size;
> > unsigned long real_align = align;
> > unsigned int shift = PAGE_SHIFT;
> >
> > 2873 if (WARN_ON_ONCE(!size))
> > return NULL;
> > <snip>
> >
> > from the dvb_dmx_init() driver:
> >
> > <snip>
> > int dvb_dmx_init(struct dvb_demux *dvbdemux)
> > {
> > int i;
> > struct dmx_demux *dmx = &dvbdemux->dmx;
> >
> > dvbdemux->cnt_storage = NULL;
> > dvbdemux->users = 0;
> > 1251 dvbdemux->filter = vmalloc(array_size(sizeof(struct dvb_demux_filter),
> > <snip> dvbdemux->filternum));
>
> Indeed.
>
> It is a mystery because array_size() should never return less than
> sizeof(struct dvb_demux_filter). That's the whole point of the
> array_size() function is that it returns ULONG_MAX if there is an
> integer overflow.
But it will return 0 if dvbdemux->filternum==0, right?
