The new pagemap ioctl contains a fast path for wr-protections without
looking into category masks. It forgets to check PM_SCAN_WP_MATCHING
before applying the wr-protections. It can cause, e.g., pte markers
installed on archs that do not even support uffd wr-protect.
WARNING: CPU: 0 PID: 5059 at mm/memory.c:1520 zap_pte_range mm/memory.c:1520 [inline]
Link: https://lkml.kernel.org/r/20231116201547.536857-3-peterx@redhat.com
Fixes: 12f6b01a0b ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+7ca4b2719dc742b8d0a4@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>