Re: [PATCH v2 0/4] fix unexpected type conversions and potential overflows

[Qi Zheng <qi.zheng@linux.dev>]

Forgot to include the changelog:

Changes in v2:

  - modified all commit messages. (suggested-by Lorenzo Stoakes)
  - added a fix patch to resolve the unexpected massive positive number
    (pointed-by Harry Yoo and sashiko)
  - fix the print type mismatch in [PATCH 3/3]
  - collect Reviewed-by

On 3/25/26 10:13 PM, Qi Zheng wrote:
> From: Qi Zheng <zhengqi.arch@bytedance.com>
> 
> Hi all,
> 
> As Harry Yoo pointed out [1], in scenarios where massive state updates occur
> (e.g., during the reparenting of LRU folios), the values passed to memcg stat
> update functions can accumulate and exceed the upper limit of a 32-bit integer.
> 
> If the parameter types are not large enough (like 'int') or are handled
> incorrectly, it can lead to severe truncation, potential overflow issues,
> and unexpected type conversion bugs.
> 
> This series aims to address these issues by correcting the parameter types
> in the relevant functions, and fixing an implicit conversion bug in
> memcg_state_val_in_pages().
> 
> This series is based on the next-20260323.
> 
> Comments and suggestions are welcome!
> 
> Thanks,
> Qi
> 
> [1]. https://lore.kernel.org/all/acDxaEgnqPI-Z4be@hyeyoo/
> 
> Qi Zheng (4):
>    mm: memcontrol: correct the type of stats_updates to unsigned long
>    mm: memcontrol: change val type to long in
>      __mod_memcg_{lruvec_}state()
>    mm: memcontrol: correct the nr_pages parameter type of
>      mem_cgroup_update_lru_size()
>    mm: memcontrol: fix unexpected massive positive number in
>      memcg_state_val_in_pages()
> 
>   include/linux/memcontrol.h   |  2 +-
>   include/trace/events/memcg.h | 10 +++++-----
>   mm/memcontrol.c              | 37 +++++++++++++++++++-----------------
>   3 files changed, 26 insertions(+), 23 deletions(-)
>