Merge tag 'io_uring-5.5-2020-01-22' of git://git.kernel.dk/linux-block

Pull io_uring fix from Jens Axboe:
"This was supposed to have gone in last week, but due to a brain fart
on my part, I forgot that we made this struct addition in the 5.5
cycle. So here it is for 5.5, to prevent having a 32 vs 64-bit
compatability issue with the files_update command"

* tag 'io_uring-5.5-2020-01-22' of git://git.kernel.dk/linux-block:
io_uring: fix compat for IORING_REGISTER_FILES_UPDATE

fs/io_uring.c

···
 		return -EINVAL;
 	if (copy_from_user(&up, arg, sizeof(up)))
 		return -EFAULT;
+	if (up.resv)
+		return -EINVAL;
 	if (check_add_overflow(up.offset, nr_args, &done))
 		return -EOVERFLOW;
 	if (done > ctx->nr_user_files)
 		return -EINVAL;
 
 	done = 0;
-	fds = (__s32 __user *) up.fds;
+	fds = u64_to_user_ptr(up.fds);
 	while (nr_args) {
 		struct fixed_file_table *table;
 		unsigned index;

include/uapi/linux/io_uring.h

···
 
 struct io_uring_files_update {
 	__u32 offset;
-	__s32 *fds;
+	__u32 resv;
+	__aligned_u64 /* __s32 * */ fds;
 };
 
 #endif