+ mm-return-an-err_ptr-from-__filemap_get_folio-fix.patch added to mm-unstable branch

+ mm-return-an-err_ptr-from-__filemap_get_folio-fix.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm-return-an-err_ptr-from-__filemap_get_folio-fix
has been added to the -mm mm-unstable branch.  Its filename is
     mm-return-an-err_ptr-from-__filemap_get_folio-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-return-an-err_ptr-from-__filemap_get_folio-fix.patch

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

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm-return-an-err_ptr-from-__filemap_get_folio-fix
Date: Fri, 10 Mar 2023 08:00:23 +0100

fix null-pointer deref

Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Naoya Horiguchi <naoya.horiguchi@linux.dev>
  Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/swap_state.c~mm-return-an-err_ptr-from-__filemap_get_folio-fix
+++ a/mm/swap_state.c
@@ -390,6 +390,8 @@ struct folio *filemap_get_incore_folio(s
 	struct swap_info_struct *si;
 	struct folio *folio = filemap_get_entry(mapping, index);
 
+	if (!folio)
+		return ERR_PTR(-ENOENT);
 	if (!xa_is_value(folio))
 		return folio;
 	if (!shmem_mapping(mapping))
_

Patches currently in -mm which might be from hch@lst.de are

ufs-dont-flush-page-immediately-for-dirsync-directories.patch
ocfs2-dont-use-write_one_page-in-ocfs2_duplicate_clusters_by_page.patch
mmjfs-move-write_one_page-folio_write_one-to-jfs.patch
mm-dont-look-at-xarray-value-entries-in-split_huge_pages_in_file.patch
mm-make-mapping_get_entry-available-outside-of-filemapc.patch
mm-use-filemap_get_entry-in-filemap_get_incore_folio.patch
shmem-remove-shmem_get_partial_folio.patch
shmem-open-code-the-page-cache-lookup-in-shmem_get_folio_gfp.patch
mm-remove-fgp_entry.patch
mm-return-an-err_ptr-from-__filemap_get_folio.patch
mm-return-an-err_ptr-from-__filemap_get_folio-fix.patch