linux-kernel - Re: [sched/preempt] BUG: KASan: out of bounds access in trace_graph

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]

Date:	Sun, 14 Jun 2015 14:33:32 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Fengguang Wu <fengguang.wu@...el.com>
Cc:	Ingo Molnar <mingo@...nel.org>,
	"Peter Zijlstra (Intel)" <peterz@...radead.org>, LKP <lkp@...org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [sched/preempt] BUG: KASan: out of bounds access in
 trace_graph_entry at addr ffff88000d717e48

On Sun, Jun 14, 2015 at 04:55:59PM +0800, Fengguang Wu wrote:
> Hi Frederic,
> 
> FYI, there are a number more bug messages showing up after this commit
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> 
> commit b30f0e3ffedfa52b1d67a302ae5860c49998e5e2
> Author:     Frederic Weisbecker <fweisbec@...il.com>
> AuthorDate: Tue May 12 16:41:49 2015 +0200
> Commit:     Ingo Molnar <mingo@...nel.org>
> CommitDate: Tue May 19 08:39:12 2015 +0200
> 
>     sched/preempt: Optimize preemption operations on __schedule() callers
>     
>     __schedule() disables preemption and some of its callers
>     (the preempt_schedule*() family) also set PREEMPT_ACTIVE.
>     
>     So we have two preempt_count() modifications that could be performed
>     at once.
>     
>     Lets remove the preemption disablement from __schedule() and pull
>     this responsibility to its callers in order to optimize preempt_count()
>     operations in a single place.
>     
>     Suggested-by: Linus Torvalds <torvalds@...ux-foundation.org>
>     Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
>     Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
>     Cc: Peter Zijlstra <peterz@...radead.org>
>     Cc: Thomas Gleixner <tglx@...utronix.de>
>     Link: http://lkml.kernel.org/r/1431441711-29753-5-git-send-email-fweisbec@gmail.com
>     Signed-off-by: Ingo Molnar <mingo@...nel.org>

Do you still see that issue after latest tip:/sched/core. I fixed it a few days ago with:

9a92e3dc6ad02208a014d0d8404ebbd697e3d5ef (preempt: Reorganize the notrace definitions a bit)
4eaca0a887eaee04fc7a3866d0f5b51b34030dfa (preempt: Use preempt_schedule_context() as the official tracing preemption point)
be690035df893385ceaac2323b29be1fb7f2a67f (sched: Make preempt_schedule_context() function-tracing safe)

But maybe there are other issues remaining.

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/