io_uring/net: don't retry connect operation on EPOLLERR

commit 8c8492ca64e79c6e0f433e8c9d2bcbd039ef83d0 upstream.

If a socket is shutdown before the connection completes, POLLERR is set
in the poll mask. However, connect ignores this as it doesn't know, and
attempts the connection again. This may lead to a bogus -ETIMEDOUT
result, where it should have noticed the POLLERR and just returned
-ECONNRESET instead.

Have the poll logic check for whether or not POLLERR is set in the mask,
and if so, mark the request as failed. Then connect can appropriately
fail the request rather than retry it.

Reported-by: Sergey Galas <ssgalas@cloud.ru>
Cc: stable@vger.kernel.org
Link: https://github.com/axboe/liburing/discussions/1335
Fixes: 3fb1bd688172 ("io_uring/net: handle -EINPROGRESS correct for IORING_OP_CONNECT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/io_uring/net.c b/io_uring/net.c
index 7f549be9abd1e6021e1e5cc20c40010286be9528..3974c417fe2644e28105dee7209c5ed707bac2eb 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1697,6 +1697,11 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags)
        int ret;
        bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
 
+       if (unlikely(req->flags & REQ_F_FAIL)) {
+               ret = -ECONNRESET;
+               goto out;
+       }
+
        file_flags = force_nonblock ? O_NONBLOCK : 0;
 
        ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,

diff --git a/io_uring/poll.c b/io_uring/poll.c
index 17dea8aa09c9b3bbe2ef39372c395284e57b54da..b93e9ebdd87c8f9b1c6b1879dc9f6695703c322d 100644 (file)
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -315,6 +315,8 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts)
                                return IOU_POLL_REISSUE;
                        }
                }
+               if (unlikely(req->cqe.res & EPOLLERR))
+                       req_set_fail(req);
                if (req->apoll_events & EPOLLONESHOT)
                        return IOU_POLL_DONE;