io_uring: fix 32-bit compatability with sendmsg/recvmsg

We must set MSG_CMSG_COMPAT if we're in compatability mode, otherwise
the iovec import for these commands will not do the right thing and fail
the command with -EINVAL.

Found by running the test suite compiled as 32-bit.

Cc: stable@vger.kernel.org
Fixes: aa1fa28fc73e ("io_uring: add support for recvmsg()")
Fixes: 0fa03c624d8f ("io_uring: add support for sendmsg()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 05eea06..6a595c1 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3001,6 +3001,11 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
        sr->len = READ_ONCE(sqe->len);
 
+#ifdef CONFIG_COMPAT
+       if (req->ctx->compat)
+               sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+
        if (!io || req->opcode == IORING_OP_SEND)
                return 0;
        /* iovec is already imported */
@@ -3153,6 +3158,11 @@ static int io_recvmsg_prep(struct io_kiocb *req,
        sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
        sr->len = READ_ONCE(sqe->len);
 
+#ifdef CONFIG_COMPAT
+       if (req->ctx->compat)
+               sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+
        if (!io || req->opcode == IORING_OP_RECV)
                return 0;
        /* iovec is already imported */