linux-kernel - Re: [PATCH] perf ftrace: Fix undefined behavior in cmp_profile

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAM9d7cj4_8LHHq22Gh-9BOPCEQk3qZizuOjF03cyQtrKSWWTRA@mail.gmail.com>
Date: Mon, 9 Dec 2024 13:48:43 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Kuan-Wei Chiu <visitorckw@...il.com>, peterz@...radead.org, mingo@...hat.com, 
	mark.rutland@....com, alexander.shishkin@...ux.intel.com, jolsa@...nel.org, 
	irogers@...gle.com, kan.liang@...ux.intel.com, adrian.hunter@...el.com, 
	jserv@...s.ncku.edu.tw, chuang@...nycu.edu.tw, 
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org, 
	stable@...r.kernel.org
Subject: Re: [PATCH] perf ftrace: Fix undefined behavior in cmp_profile_data()

On Mon, Dec 9, 2024 at 12:26 PM Arnaldo Carvalho de Melo
<acme@...nel.org> wrote:
>
> On Mon, Dec 09, 2024 at 09:02:24AM -0800, Namhyung Kim wrote:
> > Hello,
> >
> > On Mon, Dec 9, 2024 at 5:42 AM Kuan-Wei Chiu <visitorckw@...il.com> wrote:
> > >
> > > The comparison function cmp_profile_data() violates the C standard's
> > > requirements for qsort() comparison functions, which mandate symmetry
> > > and transitivity:
> > >
> > > * Symmetry: If x < y, then y > x.
> > > * Transitivity: If x < y and y < z, then x < z.
> > >
> > > When v1 and v2 are equal, the function incorrectly returns 1, breaking
> > > symmetry and transitivity. This causes undefined behavior, which can
> > > lead to memory corruption in certain versions of glibc [1].
> > >
> > > Fix the issue by returning 0 when v1 and v2 are equal, ensuring
> > > compliance with the C standard and preventing undefined behavior.
> > >
> > > Link: https://www.qualys.com/2024/01/30/qsort.txt [1]
> > > Fixes: 0f223813edd0 ("perf ftrace: Add 'profile' command")
> > > Fixes: 74ae366c37b7 ("perf ftrace profile: Add -s/--sort option")
> > > Cc: stable@...r.kernel.org
> > > Signed-off-by: Kuan-Wei Chiu <visitorckw@...il.com>
> >
> > Reviewed-by: Namhyung Kim <namhyung@...nel.org>
>
> I'm assuming you'll pick this for perf-tools, ok?
>
> Reviewed-by: Arnaldo Carvalho de Melo <acme@...hat.com>

Yep, sure.

Thanks,
Namhyung