From: Pavel Begunkov asml.silence@gmail.com
commit edf81438799ccead7122948446d7e44b083e788d upstream.
If a protocol doesn't support zerocopy it will silently fall back to copying. This type of behaviour has always been a source of troubles so it's better to fail such requests instead.
Cc: stable@vger.kernel.org # 6.0 Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://lore.kernel.org/r/2db3c7f16bb6efab4b04569cd16e6242b40c5cb3.166634642... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/net.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/io_uring/net.c +++ b/io_uring/net.c @@ -1001,6 +1001,8 @@ int io_send_zc(struct io_kiocb *req, uns sock = sock_from_file(req->file); if (unlikely(!sock)) return -ENOTSOCK; + if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags)) + return -EOPNOTSUPP;
msg.msg_name = NULL; msg.msg_control = NULL;