Merge tag 'jfs-6.3' of https://github.com/kleikamp/linux-shaggy

Pull jfs update from Dave Kleikamp:
 "Just one simple sanity check"

* tag 'jfs-6.3' of https://github.com/kleikamp/linux-shaggy:
  fs/jfs: fix shift exponent db_agl2size negative

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 765838578a722ca034b151f9ce6596123422752f..a3eb1e82694778e907658fd6ea79f0d8d2eee724 100644 (file)
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -193,7 +193,8 @@ int dbMount(struct inode *ipbmap)
        bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
        bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
        bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
-       if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG) {
+       if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG ||
+           bmp->db_agl2size < 0) {
                err = -EINVAL;
                goto err_release_metapage;
        }