6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jens Axboe axboe@kernel.dk
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 --- io_uring/net.c | 5 +++++ io_uring/poll.c | 2 ++ 2 files changed, 7 insertions(+)
--- a/io_uring/net.c +++ b/io_uring/net.c @@ -1486,6 +1486,11 @@ int io_connect(struct io_kiocb *req, uns io = &__io; }
+ 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->address, --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -288,6 +288,8 @@ static int io_poll_check_events(struct i return IOU_POLL_REISSUE; } } + if (unlikely(req->cqe.res & EPOLLERR)) + req_set_fail(req); if (req->apoll_events & EPOLLONESHOT) return IOU_POLL_DONE; if (io_is_uring_fops(req->file))