io_uring: check for valid register opcode earlier

We only check the register opcode value inside the restricted ring
section, move it into the main io_uring_register() function instead
and check it up front.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ac5d39eeb3d1eaffea0c68ed40efa9d2e76b59dd..58ac13b69dc8dc8a9ae54497091c12be55ec1d48 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -4020,8 +4020,6 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
                return -EEXIST;
 
        if (ctx->restricted) {
-               if (opcode >= IORING_REGISTER_LAST)
-                       return -EINVAL;
                opcode = array_index_nospec(opcode, IORING_REGISTER_LAST);
                if (!test_bit(opcode, ctx->restrictions.register_op))
                        return -EACCES;
@@ -4177,6 +4175,9 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
        long ret = -EBADF;
        struct fd f;
 
+       if (opcode >= IORING_REGISTER_LAST)
+               return -EINVAL;
+
        f = fdget(fd);
        if (!f.file)
                return -EBADF;