Commit f6250e20 authored Jul 10, 2023 by Darrick J. Wong

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>

parent a49bbce5

fs/xfs/libxfs/xfs_da_format.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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 */

fs/xfs/xfs_ondisk.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);