xfs: sb_spino_align is not verified

commit 59e43f5479cce106d71c0b91a297c7ad1913176c upstream.

It's just read in from the superblock and used without doing any
validity checks at all on the value.

Fixes: fb4f2b4e5a82 ("xfs: add sparse inode chunk alignment superblock field")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
[djwong: actually tag for 6.12 because upstream maintainer ignored cc-stable tag]
Link: https://lore.kernel.org/linux-xfs/20241024165544.GI21853@frogsfrogsfrogs/
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 02ebcbc4882f5b74f2baadf62e22bd70c234e786..9e0ae312bc8035d2b11a592e999753d150ac1f8c 100644 (file)
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -391,6 +391,20 @@ xfs_validate_sb_common(
                                         sbp->sb_inoalignmt, align);
                                return -EINVAL;
                        }
+
+                       if (!sbp->sb_spino_align ||
+                           sbp->sb_spino_align > sbp->sb_inoalignmt ||
+                           (sbp->sb_inoalignmt % sbp->sb_spino_align) != 0) {
+                               xfs_warn(mp,
+                               "Sparse inode alignment (%u) is invalid.",
+                                       sbp->sb_spino_align);
+                               return -EINVAL;
+                       }
+               } else if (sbp->sb_spino_align) {
+                       xfs_warn(mp,
+                               "Sparse inode alignment (%u) should be zero.",
+                               sbp->sb_spino_align);
+                       return -EINVAL;
                }
        } else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
                                XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {