The patch titled Subject: mm/migrate.c: fix do_pages_stat to use compat_uptr_t has been added to the -mm mm-hotfixes-unstable branch. Its filename is fix-do_pages_stat-to-use-compat_uptr_t.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days

------------------------------------------------------ From: Christoph Berg myon@debian.org Subject: mm/migrate.c: fix do_pages_stat to use compat_uptr_t Date: Wed, 25 Jun 2025 17:24:14 +0200

For arrays with more than 16 entries, the old code would incorrectly advance the pages pointer by 16 words instead of 16 compat_uptr_t.

Link: https://lkml.kernel.org/r/aFwUnu7ObizycCZ8@msg.df7cb.de Signed-off-by: Christoph Berg myon@debian.org Suggested-by: Bertrand Drouvot bertranddrouvot.pg@gmail.com Cc: Alistair Popple apopple@nvidia.com Cc: Byungchul Park byungchul@sk.com Cc: David Hildenbrand david@redhat.com Cc: Gregory Price gourry@gourry.net Cc: "Huang, Ying" ying.huang@linux.alibaba.com Cc: Joshua Hahn joshua.hahnjy@gmail.com Cc: Mathew Brost matthew.brost@intel.com Cc: Rakie Kim rakie.kim@sk.com Cc: Zi Yan ziy@nvidia.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/migrate.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/mm/migrate.c~fix-do_pages_stat-to-use-compat_uptr_t +++ a/mm/migrate.c @@ -2444,7 +2444,13 @@ static int do_pages_stat(struct mm_struc if (copy_to_user(status, chunk_status, chunk_nr * sizeof(*status))) break;

- pages += chunk_nr; + if (in_compat_syscall()) { + compat_uptr_t __user *pages32 = (compat_uptr_t __user *)pages; + + pages32 += chunk_nr; + pages = (const void __user * __user *) pages32; + } else + pages += chunk_nr; status += chunk_nr; nr_pages -= chunk_nr; } _

Patches currently in -mm which might be from myon@debian.org are

fix-do_pages_stat-to-use-compat_uptr_t.patch