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 C67998465 for ; Wed, 20 Sep 2023 11:51:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4783EC433CB; Wed, 20 Sep 2023 11:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695210692; bh=lC0320bE+MUSpYUq1M4XR00wOSdL0QPTABCw/MWwoNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l8vPaivs7I5pVP9nZGEtgsStaRmkg/2jIIHMnLT2tujNvjfJt1LamLEasLGnWjAuk pZ3D8JSKOPxQciBH+eRHb+7A97b7R+q9QrJ7DcY/MLgqZz44mDrc6sVD3OvOhgJ8pn pLWa0ar9HJewlsnVkBy6x82/em2dYSGDQMWcLSs0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+a4c6e5ef999b68b26ed1@syzkaller.appspotmail.com, Pavel Begunkov , Jens Axboe Subject: [PATCH 6.5 170/211] io_uring/net: fix iter retargeting for selected buf Date: Wed, 20 Sep 2023 13:30:14 +0200 Message-ID: <20230920112851.160600434@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112845.859868994@linuxfoundation.org> References: <20230920112845.859868994@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Begunkov commit c21a8027ad8a68c340d0d58bf1cc61dcb0bc4d2f upstream. When using selected buffer feature, io_uring delays data iter setup until later. If io_setup_async_msg() is called before that it might see not correctly setup iterator. Pre-init nr_segs and judge from its state whether we repointing. Cc: stable@vger.kernel.org Reported-by: syzbot+a4c6e5ef999b68b26ed1@syzkaller.appspotmail.com Fixes: 0455d4ccec548 ("io_uring: add POLL_FIRST support for send/sendmsg and recv/recvmsg") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/0000000000002770be06053c7757@google.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/net.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/io_uring/net.c +++ b/io_uring/net.c @@ -183,6 +183,10 @@ static int io_setup_async_msg(struct io_ memcpy(async_msg, kmsg, sizeof(*kmsg)); if (async_msg->msg.msg_name) async_msg->msg.msg_name = &async_msg->addr; + + if ((req->flags & REQ_F_BUFFER_SELECT) && !async_msg->msg.msg_iter.nr_segs) + return -EAGAIN; + /* if were using fast_iov, set it to the new one */ if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) { size_t fast_idx = iter_iov(&kmsg->msg.msg_iter) - kmsg->fast_iov; @@ -542,6 +546,7 @@ static int io_recvmsg_copy_hdr(struct io struct io_async_msghdr *iomsg) { iomsg->msg.msg_name = &iomsg->addr; + iomsg->msg.msg_iter.nr_segs = 0; #ifdef CONFIG_COMPAT if (req->ctx->compat)