Hello, the previous patch did not correctly check and release the
relevant pointers. Version 2 has fixed these issues. Thank you for
your response.
On Thu, Nov 7, 2024 at 8:53 PM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> On 07.11.24 13:41, Qiu-ji Chen wrote:
> > The function call alloc_percpu() returns a pointer to the memory address,
> > but it hasn't been checked. Our static analysis tool indicates that null
> > pointer dereference may exist in pointer zone->per_cpu_pageset. It is
> > always safe to judge the null pointer before use.
> >
> > Signed-off-by: Qiu-ji Chen <chenqiuji666@xxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c")
> > ---
> > V2:
> > Fixed the incorrect code logic.
> > Thanks David Hildenbrand for helpful suggestion.
> > ---
> > mm/page_alloc.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 8afab64814dc..7c8a74fd02d6 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -5703,8 +5703,14 @@ void __meminit setup_zone_pageset(struct zone *zone)
> > /* Size may be 0 on !SMP && !NUMA */
> > if (sizeof(struct per_cpu_zonestat) > 0)
> > zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat);
> > + if (!zone->per_cpu_zonestats)
> > + return;
> >
> > zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages);
> > + if (!zone->per_cpu_pageset) {
> > + free_percpu(zone->per_cpu_zonestats);
> > + return;
> > + }
> > for_each_possible_cpu(cpu) {
> > struct per_cpu_pages *pcp;
> > struct per_cpu_zonestat *pzstats;
>
> Unmodified patch, likely not what you wanted to send?
>
>
> --
> Cheers,
>
> David / dhildenb
>
