From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 63C05288D0; Wed, 17 Jun 2026 12:11:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781698261; cv=none; b=QAFTw/5QvZLWYEJY3ixxpg9Yg0YZrc8W4fqWJoY80jUN9JZN9SeGOqnRll3G3jqJVLQAAlmJrSXCfKqcAfjN7DVKy7vHfC9vXvb28kuxY22cW5dCNTRgv2yWZje2ZXxxSoX4gbWf/9j5bBEK/9V/lDV3XKbyNB3/4zpPLEBUTow= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781698261; c=relaxed/simple; bh=X6HpM5Za44X7ZepaSExNy+W5QBtUM4vthFa/g0qfZHE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=h+bhZNJCvZ0LAbua9+CEJS2A9hh92dqn+iMo4clrZ9pqYAKLlG4i2sKOS0dF1ASFcbTfyTLR0MDYdhC706vuc+4+dlfH1sCPih2LBRB8Z7MeOgpl0/qpKYszc+sl99fJ03hp9TwGJNyTsYdfSz14EKNfdHudU7K3hbMvn7823rc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LXsOIYKr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LXsOIYKr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 595821F000E9; Wed, 17 Jun 2026 12:10:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781698260; bh=oGH4exJeiKznSQXGrDnbISb7qf5M+zPLl1Qxv/C3Ccc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=LXsOIYKrowM0PHEHQ13vCxCeNrgzz1Ps4BvrtD9w1HLpOQHKCefO4seANf/coE8QS fOjTK2Jc7G8HmX71gKBZMiXOVXpVg/2V+NbLDBrRq1deTedyBJmMWgDWTZrCjphBYV nnPlzvpqCFt8v6FE70tCgTPIfQLZOriSeXCbMs3rpCwIpX0NWKypopE1EDFSVYlxsr j2O6mbNiCAZKgfqNaVpJTGzpB+cOly+a0+/MMeT1LKNJhi7YS6wrOfg/rE1giBM0eI GSQFWiXBwEPbkh/VszliGVCnZgZAg94aPpXXurhKqvQrmPPHoZUTNUDAk7szjyFKIU NP5DLvgoQMaMQ== Date: Wed, 17 Jun 2026 15:10:55 +0300 From: Leon Romanovsky To: Zhenhao Wan Cc: "Md. Haris Iqbal" , Jack Wang , Jason Gunthorpe , Danil Kipnis , Jack Wang , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Yuhao Jiang , stable@vger.kernel.org Subject: Re: [PATCH] RDMA/rtrs-srv: Reject usr_len larger than off in process_{read,write} Message-ID: <20260617121055.GY327369@unreal> References: <20260617-rtrs-srv-usr-len-underflow-v1-1-942e6414150a@gmail.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260617-rtrs-srv-usr-len-underflow-v1-1-942e6414150a@gmail.com> On Wed, Jun 17, 2026 at 12:52:00AM +0800, Zhenhao Wan wrote: > process_read() and process_write() derive the data length of an I/O > request as: > > usr_len = le16_to_cpu(req->usr_len); > data_len = off - usr_len; > > off comes from the RDMA-Write-with-imm immediate and is only bounded > above (off < max_chunk_size) in rtrs_srv_rdma_done(). usr_len is read > from the chunk buffer the remote peer fills over RDMA, so it is peer > controlled over the full u16 range and is not checked against off. > > If a peer sends usr_len > off, the size_t subtraction underflows and > the pointer data + data_len passed to the ->rdma_ev() callback points > before the chunk. The in-tree consumer rnbd_srv_rdma_ev() dereferences > it as the message header (le16_to_cpu(hdr->type)) before validating it; > this is an out-of-bounds read reachable from a remote peer. > > Reject usr_len > off before computing data_len in both paths, via the > existing send_err_msg path. For a well-formed request off is the total > length data_len + usr_len, so usr_len <= off holds and valid requests > are unaffected. > > Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality") > Reported-by: Yuhao Jiang > Cc: stable@vger.kernel.org > Signed-off-by: Zhenhao Wan > --- > drivers/infiniband/ulp/rtrs/rtrs-srv.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) It is already fixed in the commit 54bf38b27afc ("RDMA/rtrs-srv: Fix integer underflow in process_read and process_write") Thanks