From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D65413AC4 for ; Mon, 26 Jun 2023 18:29:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F915C433CB; Mon, 26 Jun 2023 18:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804141; bh=SesFy4arrJuGxDVjfRSOZoNezECgi4DJkjPU9W0ROvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hX1F+qPOcJvOIi2Kl2mt0TwX3VVpYKen3Kt9bPcrMoytiHR9+a4IDgZCYlD96Q/xL glsKEgiW2hP2IonB6LBc38/5/Zn4OPDolUcWOTDPKdeCFe2M0EWqD3WFPZGdUm2huI RPQ35ziJjygp2UODhsg8Jf94nEFTLNq66fQcxHJs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stefan Metzmacher , Jens Axboe Subject: [PATCH 6.1 056/170] io_uring/net: disable partial retries for recvmsg with cmsg Date: Mon, 26 Jun 2023 20:10:25 +0200 Message-ID: <20230626180803.093850140@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180800.476539630@linuxfoundation.org> References: <20230626180800.476539630@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jens Axboe commit 78d0d2063bab954d19a1696feae4c7706a626d48 upstream. We cannot sanely handle partial retries for recvmsg if we have cmsg attached. If we don't, then we'd just be overwriting the initial cmsg header on retries. Alternatively we could increment and handle this appropriately, but it doesn't seem worth the complication. Move the MSG_WAITALL check into the non-multishot case while at it, since MSG_WAITALL is explicitly disabled for multishot anyway. Link: https://lore.kernel.org/io-uring/0b0d4411-c8fd-4272-770b-e030af6919a0@kernel.dk/ Cc: stable@vger.kernel.org # 5.10+ Reported-by: Stefan Metzmacher Reviewed-by: Stefan Metzmacher Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/net.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/io_uring/net.c +++ b/io_uring/net.c @@ -781,16 +781,19 @@ retry_multishot: flags = sr->msg_flags; if (force_nonblock) flags |= MSG_DONTWAIT; - if (flags & MSG_WAITALL) - min_ret = iov_iter_count(&kmsg->msg.msg_iter); kmsg->msg.msg_get_inq = 1; - if (req->flags & REQ_F_APOLL_MULTISHOT) + if (req->flags & REQ_F_APOLL_MULTISHOT) { ret = io_recvmsg_multishot(sock, sr, kmsg, flags, &mshot_finished); - else + } else { + /* disable partial retry for recvmsg with cmsg attached */ + if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen) + min_ret = iov_iter_count(&kmsg->msg.msg_iter); + ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg, kmsg->uaddr, flags); + } if (ret < min_ret) { if (ret == -EAGAIN && force_nonblock) {