The quilt patch titled Subject: mm/pagemap: fix wr-protect even if PM_SCAN_WP_MATCHING not set has been removed from the -mm tree. Its filename was mm-pagemap-fix-wr-protect-even-if-pm_scan_wp_matching-not-set.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Peter Xu <peterx@xxxxxxxxxx> Subject: mm/pagemap: fix wr-protect even if PM_SCAN_WP_MATCHING not set Date: Thu, 16 Nov 2023 15:15:46 -0500 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@xxxxxxxxxx Fixes: 12f6b01a0bcb ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag") Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reported-by: syzbot+7ca4b2719dc742b8d0a4@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Andrei Vagin <avagin@xxxxxxxxx> Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/proc/task_mmu.c~mm-pagemap-fix-wr-protect-even-if-pm_scan_wp_matching-not-set +++ a/fs/proc/task_mmu.c @@ -2156,7 +2156,7 @@ static int pagemap_scan_pmd_entry(pmd_t return 0; } - if (!p->vec_out) { + if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) { /* Fast path for performing exclusive WP */ for (addr = start; addr != end; pte++, addr += PAGE_SIZE) { if (pte_uffd_wp(ptep_get(pte))) _ Patches currently in -mm which might be from peterx@xxxxxxxxxx are fs-kconfig-make-hugetlbfs-a-menuconfig.patch mm-gup-fix-follow_devmap_pd-on-page==null-handling.patch