From: Pavel Begunkov asml.silence@gmail.com
commit 8579538c89e33ce78be2feb41e07489c8cbf8f31 upstream.
IORING_SETUP_R_DISABLED rings don't have the submitter task set, so it's not always safe to use ->submitter_task. Disallow posting msg_ring messaged to disabled rings. Also add task NULL check for loosy sync around testing for IORING_SETUP_R_DISABLED.
Cc: stable@vger.kernel.org Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/msg_ring.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -30,6 +30,8 @@ static int io_msg_ring_data(struct io_ki
if (msg->src_fd || msg->dst_fd || msg->flags) return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD;
if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0, true)) return 0; @@ -84,6 +86,8 @@ static int io_msg_send_fd(struct io_kioc
if (target_ctx == ctx) return -EINVAL; + if (target_ctx->flags & IORING_SETUP_R_DISABLED) + return -EBADFD;
ret = io_double_lock_ctx(ctx, target_ctx, issue_flags); if (unlikely(ret))