From: Joonwon Kang <kjw1627@xxxxxxxxx> commit 60f2c82ed20bde57c362e66f796cf9e0e38a6dbb upstream. While no uses in the kernel triggered this case, it was possible to have a false negative where a struct contains other structs which contain only function pointers because of unreachable code in is_pure_ops_struct(). Signed-off-by: Joonwon Kang <kjw1627@xxxxxxxxx> Link: https://lore.kernel.org/r/20190727155841.GA13586@host Fixes: 313dd1b62921 ("gcc-plugins: Add the randstruct plugin") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- scripts/gcc-plugins/randomize_layout_plugin.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -443,13 +443,13 @@ static int is_pure_ops_struct(const_tree if (node == fieldtype) continue; - if (!is_fptr(fieldtype)) - return 0; - - if (code != RECORD_TYPE && code != UNION_TYPE) + if (code == RECORD_TYPE || code == UNION_TYPE) { + if (!is_pure_ops_struct(fieldtype)) + return 0; continue; + } - if (!is_pure_ops_struct(fieldtype)) + if (!is_fptr(fieldtype)) return 0; }
