[3/3] xfs: convert flex-array declarations in xfs attr shortform objects

Commit Message

Darrick J. Wong July 14, 2023, 2:42 p.m. UTC

From: Darrick J. Wong <[e-mail]>

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 <[e-mail]>
---
 fs/xfs/libxfs/xfs_da_format.h |    2 +-
 fs/xfs/xfs_ondisk.h           |    1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
index b2362717c42e..f9015f88eca7 100644
--- 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 37be297f2532..c4cc99b70dd3 100644
--- 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);