From: Sean Young <sean@xxxxxxxx> commit 8a866fee3909c49738e1c4429a8d2b9bf27e015d upstream. If you try to store u64 in a kfifo (or a struct with u64 members), then the buf member of __STRUCT_KFIFO_PTR will cause 4 bytes padding due to alignment (note that struct __kfifo is 20 bytes on 32 bit). That in turn causes the __is_kfifo_ptr() to fail, which is caught by kfifo_alloc(), which now returns EINVAL. So, ensure that __is_kfifo_ptr() compares to the right structure. Signed-off-by: Sean Young <sean@xxxxxxxx> Acked-by: Stefani Seibold <stefani@xxxxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> Signed-off-by: Matthew Weber <matthew.weber@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/kfifo.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/kfifo.h +++ b/include/linux/kfifo.h @@ -113,7 +113,8 @@ struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PT * array is a part of the structure and the fifo type where the array is * outside of the fifo structure. */ -#define __is_kfifo_ptr(fifo) (sizeof(*fifo) == sizeof(struct __kfifo)) +#define __is_kfifo_ptr(fifo) \ + (sizeof(*fifo) == sizeof(STRUCT_KFIFO_PTR(typeof(*(fifo)->type)))) /** * DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
