[merged mm-stable] mm-userfaultfd-add-new-uffdio_poison-ioctl-fix.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: mm: userfaultfd: add new UFFDIO_POISON ioctl: fix
has been removed from the -mm tree.  Its filename was
     mm-userfaultfd-add-new-uffdio_poison-ioctl-fix.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: mm: userfaultfd: add new UFFDIO_POISON ioctl: fix
Date: Tue, 11 Jul 2023 18:27:17 -0700 (PDT)

Smatch has observed that pte_offset_map_lock() is now allowed to fail, and
then ptl should not be unlocked.  Use -EAGAIN here like elsewhere.

Link: https://lkml.kernel.org/r/bc7bba61-d34f-ad3a-ccf1-c191585ef851@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/userfaultfd.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/mm/userfaultfd.c~mm-userfaultfd-add-new-uffdio_poison-ioctl-fix
+++ a/mm/userfaultfd.c
@@ -300,7 +300,10 @@ static int mfill_atomic_pte_poison(pmd_t
 	spinlock_t *ptl;
 
 	_dst_pte = make_pte_marker(PTE_MARKER_POISONED);
+	ret = -EAGAIN;
 	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
+	if (!dst_pte)
+		goto out;
 
 	if (mfill_file_over_size(dst_vma, dst_addr)) {
 		ret = -EFAULT;
@@ -319,6 +322,7 @@ static int mfill_atomic_pte_poison(pmd_t
 	ret = 0;
 out_unlock:
 	pte_unmap_unlock(dst_pte, ptl);
+out:
 	return ret;
 }
 
_

Patches currently in -mm which might be from hughd@google.com are