Use flex_cpy() instead of memcpy() to copy the bui_fmt flexible array structure, which will perform bounds checking internally. Avoids the false positive warning seen under FORTIFY_SOURCE: memcpy: detected field-spanning write (size 48) of single field "dst_bui_fmt" at fs/xfs/xfs_bmap_item.c:628 (size 16) Reported-by: Zorro Lang <zlang@xxxxxxxxxx> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216563 Cc: "Darrick J. Wong" <djwong@xxxxxxxxxx> Cc: linux-xfs@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- fs/xfs/xfs_bmap_item.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c index 51f66e982484..5f135893df66 100644 --- a/fs/xfs/xfs_bmap_item.c +++ b/fs/xfs/xfs_bmap_item.c @@ -24,6 +24,7 @@ #include "xfs_error.h" #include "xfs_log_priv.h" #include "xfs_log_recover.h" +#include <linux/flex_array.h> struct kmem_cache *xfs_bui_cache; struct kmem_cache *xfs_bud_cache; @@ -624,10 +625,10 @@ xfs_bui_copy_format( src_bui_fmt = buf->i_addr; len = xfs_bui_log_format_sizeof(src_bui_fmt->bui_nextents); - if (buf->i_len == len) { - memcpy(dst_bui_fmt, src_bui_fmt, len); + if (buf->i_len == len && + __flex_cpy(dst_bui_fmt, src_bui_fmt, + bui_extents, bui_nextents, __passthru) == 0) return 0; - } XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL); return -EFSCORRUPTED; } -- 2.34.1
