From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752081AbeEOTAu (ORCPT ); Tue, 15 May 2018 15:00:50 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:52228 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751219AbeEOTAs (ORCPT ); Tue, 15 May 2018 15:00:48 -0400 Date: Tue, 15 May 2018 16:00:33 -0300 From: Mauro Carvalho Chehab To: "Gustavo A. R. Silva" Cc: Dan Carpenter , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/11] media: tm6000: fix potential Spectre variant 1 Message-ID: <20180515160033.156f119c@vento.lan> In-Reply-To: References: <3d4973141e218fb516422d3d831742d55aaa5c04.1524499368.git.gustavo@embeddedor.com> <20180423152455.363d285c@vento.lan> <3ab9c4c9-0656-a08e-740e-394e2e509ae9@embeddedor.com> <20180423161742.66f939ba@vento.lan> <99e158c0-1273-2500-da9e-b5ab31cba889@embeddedor.com> <20180426204241.03a42996@vento.lan> <20180515085953.65bfa107@vento.lan> <20180515141655.idzuh2jfdkuu5grs@mwanda> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, 15 May 2018 12:29:10 -0500 "Gustavo A. R. Silva" escreveu: > On 05/15/2018 09:16 AM, Dan Carpenter wrote: > >>> > >>> I'm curious about how you finally resolved to handle these issues. > >>> > >>> I noticed Smatch is no longer reporting them. > >> > >> There was no direct fix for it, but maybe this patch has something > >> to do with the smatch error report cleanup: > >> > >> commit 3ad3b7a2ebaefae37a7eafed0779324987ca5e56 > >> Author: Sami Tolvanen > >> Date: Tue May 8 13:56:12 2018 -0400 > >> > >> media: v4l2-ioctl: replace IOCTL_INFO_STD with stub functions > >> > >> This change removes IOCTL_INFO_STD and adds stub functions where > >> needed using the DEFINE_V4L_STUB_FUNC macro. This fixes indirect call > >> mismatches with Control-Flow Integrity, caused by calling standard > >> ioctls using a function pointer that doesn't match the function type. > >> > >> Signed-off-by: Sami Tolvanen > >> Signed-off-by: Hans Verkuil > >> Signed-off-by: Mauro Carvalho Chehab > >> > > Thanks, Mauro. > > > > > Possibly... There was an ancient bug in Smatch's function pointer > > handling. I just pushed a fix for it now so the warning is there on > > linux-next. > > > > Dan, > > These are all the Spectre media issues I see smatch is reporting in > linux-next-20180515: Yeah, that's the same I'm getting from media upstream. > drivers/media/cec/cec-pin-error-inj.c:170 cec_pin_error_inj_parse_line() > warn: potential spectre issue 'pin->error_inj_args' This one seems a false positive, as the index var is u8 and the array has 256 elements, as the userspace input from 'op' is initialized with: u8 v; u32 op; if (!kstrtou8(token, 0, &v)) op = v; > drivers/media/dvb-core/dvb_ca_en50221.c:1479 dvb_ca_en50221_io_write() > warn: potential spectre issue 'ca->slot_info' (local cap) This one seems a real issue to me. Sent a patch for it. > drivers/media/dvb-core/dvb_net.c:252 handle_one_ule_extension() warn: > potential spectre issue 'p->ule_next_hdr' I failed to see what's wrong here, or if this is exploited. > > I pulled the latest changes from the smatch repository and compiled it. > > I'm running smatch v0.5.0-4459-g2f66d40 now. Is this the latest version? > > I wonder if there is anything I might be missing. Here, I'm at this commit: commit 2f66d40cbf57b0bd581fe75447d2a8625fc7bb1d (origin/master, origin/HEAD) Author: Dan Carpenter Date: Tue May 15 16:35:20 2018 +0300 db: make call_implies rows unique Plus the diff below (that won't affect Spectre errors). Regards, Mauro > > Thanks > -- > Gustavo > diff --git a/check_missing_break.c b/check_missing_break.c index 434b7283fc94..5bba6e919521 100644 --- a/check_missing_break.c +++ b/check_missing_break.c @@ -73,7 +73,7 @@ static void print_missing_break(struct expression *expr) last_print_expr = get_switch_expr(); name = expr_to_var(expr); - sm_msg("warn: missing break? reassigning '%s'", name); +// sm_msg("warn: missing break? reassigning '%s'", name); free_string(name); } diff --git a/smatch_flow.c b/smatch_flow.c index dc0e78824370..cd72a9ded375 100644 --- a/smatch_flow.c +++ b/smatch_flow.c @@ -1005,8 +1005,7 @@ void __split_stmt(struct statement *stmt) __bail_on_rest_of_function = 1; final_pass = 1; - sm_msg("Function too hairy. Giving up. %lu seconds", - stop.tv_sec - fn_start_time.tv_sec); + sm_msg("__split_smt: function too hairy. Giving up."); fake_a_return(); final_pass = 0; /* turn off sm_msg() from here */ return; diff --git a/smatch_implied.c b/smatch_implied.c index 3588816361fe..f3ccd4b6d79e 100644 --- a/smatch_implied.c +++ b/smatch_implied.c @@ -594,7 +594,7 @@ static void separate_and_filter(struct sm_state *sm, int comparison, struct rang gettimeofday(&time_after, NULL); sec = time_after.tv_sec - time_before.tv_sec; - if (sec > 20) { + if (sec > 60) { sm->nr_children = 4000; sm_msg("Function too hairy. Ignoring implications after %d seconds.", sec); } diff --git a/smatch_slist.c b/smatch_slist.c index e1eb1b999b2a..2f8ba34a4b9a 100644 --- a/smatch_slist.c +++ b/smatch_slist.c @@ -237,12 +237,14 @@ char *alloc_sname(const char *str) int out_of_memory(void) { /* - * I decided to use 50M here based on trial and error. + * I decided to use 6GB here based on trial and error. * It works out OK for the kernel and so it should work * for most other projects as well. */ - if (sm_state_counter * sizeof(struct sm_state) >= 100000000) + if (sm_state_counter * sizeof(struct sm_state) >= 6000000000) { + sm_msg("Out of memory"); return 1; + } return 0; } Thanks, Mauro