Merge branch 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap fix from Darrick Wong:
 "A single fix to the iomap code which fixes some drama when someone
  gives us a {de,ma}liciously fragmented swap file"

* 'iomap-5.12-fixes' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Fix negative assignment to unsigned sis->pages in iomap_swapfile_activate

diff --git a/fs/iomap/swapfile.c b/fs/iomap/swapfile.c
index a648dbf..a5e478d 100644 (file)
--- a/fs/iomap/swapfile.c
+++ b/fs/iomap/swapfile.c
@@ -170,6 +170,16 @@ int iomap_swapfile_activate(struct swap_info_struct *sis,
                        return ret;
        }
 
+       /*
+        * If this swapfile doesn't contain even a single page-aligned
+        * contiguous range of blocks, reject this useless swapfile to
+        * prevent confusion later on.
+        */
+       if (isi.nr_pages == 0) {
+               pr_warn("swapon: Cannot find a single usable page in file.\n");
+               return -EINVAL;
+       }
+
        *pagespan = 1 + isi.highest_ppage - isi.lowest_ppage;
        sis->max = isi.nr_pages;
        sis->pages = isi.nr_pages - 1;