On Fri, Nov 29, 2024 at 5:14 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
>
> vm_module_tags_populate() calculation of the populated area assumes that
> area starts at a page boundary and therefore when new pages are allocation,
> the end of the area is page-aligned as well. If the start of the area is
> not page-aligned then allocating a page and incrementing the end of the
> area by PAGE_SIZE leads to an area at the end but within the area boundary
> which is not populated. Accessing this are will lead to a kernel panic.
> Fix the calculation by down-aligning the start of the area and using that
> as the location allocated pages are mapped to.
>
> Fixes: 0f9b685626da ("alloc_tag: populate memory for module tags as needed")
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-lkp/202411132111.6a221562-lkp@xxxxxxxxx
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Acked-by: Yu Zhao <yuzhao@xxxxxxxxxx>
