xfs: convert flex-array declarations in xfs attr shortform objects

As of 6.5-rc1, UBSAN trips over the ondisk extended attribute shortform
definitions using an array length of 1 to pretend to be a flex array.
Kernel compilers have to support unbounded array declarations, so let's
correct this.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>

diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
index b236271..f9015f8 100644 (file)
--- a/fs/xfs/libxfs/xfs_da_format.h
+++ b/fs/xfs/libxfs/xfs_da_format.h
@@ -591,7 +591,7 @@ struct xfs_attr_shortform {
                uint8_t valuelen;       /* actual length of value (no NULL) */
                uint8_t flags;  /* flags bits (see xfs_attr_leaf.h) */
                uint8_t nameval[];      /* name & value bytes concatenated */
-       } list[1];                      /* variable sized array */
+       } list[];                       /* variable sized array */
 };
 
 typedef struct xfs_attr_leaf_map {     /* RLE map of free bytes */

diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
index 37be297..c4cc99b 100644 (file)
--- a/fs/xfs/xfs_ondisk.h
+++ b/fs/xfs/xfs_ondisk.h
@@ -89,6 +89,7 @@ xfs_check_ondisk_structs(void)
        XFS_CHECK_OFFSET(xfs_attr_leaf_name_remote_t, namelen,  8);
        XFS_CHECK_OFFSET(xfs_attr_leaf_name_remote_t, name,     9);
        XFS_CHECK_STRUCT_SIZE(xfs_attr_leafblock_t,             32);
+       XFS_CHECK_STRUCT_SIZE(struct xfs_attr_shortform,        4);
        XFS_CHECK_OFFSET(struct xfs_attr_shortform, hdr.totsize, 0);
        XFS_CHECK_OFFSET(struct xfs_attr_shortform, hdr.count,   2);
        XFS_CHECK_OFFSET(struct xfs_attr_shortform, list[0].namelen,    4);