If the recv returns zero, or an error, then it doesn't matter if more data has already been received for this buffer. A condition like that should terminate the multishot receive. Rather than pass in the collected return value, pass in whether to terminate or keep the recv going separately. Note that this isn't a bug right now, as the only way to get there is via setting MSG_WAITALL with multishot receive. And if an application does that, then -EINVAL is returned anyway. But it seems like an easy bug to introduce, so let's make it a bit more explicit. Link: https://github.com/axboe/liburing/issues/1246 Cc: stable@xxxxxxxxxxxxxxx Fixes: b3fdea6ecb55 ("io_uring: multishot recv") Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> diff --git a/io_uring/net.c b/io_uring/net.c index f10f5a22d66a..18507658a921 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -1133,6 +1133,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) int ret, min_ret = 0; bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; size_t len = sr->len; + bool mshot_finished; if (!(req->flags & REQ_F_POLLED) && (sr->flags & IORING_RECVSEND_POLL_FIRST)) @@ -1187,6 +1188,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) req_set_fail(req); } + mshot_finished = ret <= 0; if (ret > 0) ret += sr->done_io; else if (sr->done_io) @@ -1194,7 +1196,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) else io_kbuf_recycle(req, issue_flags); - if (!io_recv_finish(req, &ret, kmsg, ret <= 0, issue_flags)) + if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags)) goto retry_multishot; return ret;
