io_uring/net: fix accept multishot handling

Commit f6a89bf5278d6e15016a736db67043560d1b50d5 upstream.

REQ_F_APOLL_MULTISHOT doesn't guarantee it's executed from the multishot
context, so a multishot accept may get executed inline, fail
io_req_post_cqe(), and ask the core code to kill the request with
-ECANCELED by returning IOU_STOP_MULTISHOT even when a socket has been
accepted and installed.

Cc: stable@vger.kernel.org
Fixes: 390ed29b5e425 ("io_uring: add IORING_ACCEPT_MULTISHOT for accept")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/51c6deb01feaa78b08565ca8f24843c017f5bc80.1740331076.git.asml.silence@gmail.com
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 1a0e98e19dc0ed1a285dbcdf97fc49aeb0b43140..4948a67bbac4805f6de92d5b1505cd7570ef9075 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1438,6 +1438,8 @@ retry:
                goto retry;
 
        io_req_set_res(req, ret, 0);
+       if (!(issue_flags & IO_URING_F_MULTISHOT))
+               return IOU_OK;
        return IOU_STOP_MULTISHOT;
 }