From: Sasha Levin <sashal@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
linux-kernel@vger.kernel.org,
John Stultz <john.stultz@linaro.org>,
stable@vger.kernel.org, gregkh@linuxfoundation.org,
Peter Zijlstra <peterz@infradead.org>,
Michael Kerrisk <mtk.manpages@gmail.com>
Subject: Re: [PATCH stable 4.9] posix-timers: Sanitize overrun handling
Date: Thu, 8 Nov 2018 10:46:25 -0500 [thread overview]
Message-ID: <20181108154625.GC8097@sasha-vm> (raw)
In-Reply-To: <alpine.DEB.2.21.1811080747450.1666@nanos.tec.linutronix.de>
On Thu, Nov 08, 2018 at 07:48:16AM +0100, Thomas Gleixner wrote:
>Florian,
>
>On Wed, 7 Nov 2018, Florian Fainelli wrote:
>> On 11/1/18 1:02 PM, Florian Fainelli wrote:
>> > From: Thomas Gleixner <tglx@linutronix.de>
>> >
>> > [ Upstream commit 78c9c4dfbf8c04883941445a195276bb4bb92c76 ]
>> >
>> > The posix timer overrun handling is broken because the forwarding functions
>> > can return a huge number of overruns which does not fit in an int. As a
>> > consequence timer_getoverrun(2) and siginfo::si_overrun can turn into
>> > random number generators.
>> >
>> > The k_clock::timer_forward() callbacks return a 64 bit value now. Make
>> > k_itimer::ti_overrun[_last] 64bit as well, so the kernel internal
>> > accounting is correct. 3Remove the temporary (int) casts.
>> >
>> > Add a helper function which clamps the overrun value returned to user space
>> > via timer_getoverrun(2) or siginfo::si_overrun limited to a positive value
>> > between 0 and INT_MAX. INT_MAX is an indicator for user space that the
>> > overrun value has been clamped.
>> >
>> > Reported-by: Team OWL337 <icytxw@gmail.com>
>> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>> > Acked-by: John Stultz <john.stultz@linaro.org>
>> > Cc: Peter Zijlstra <peterz@infradead.org>
>> > Cc: Michael Kerrisk <mtk.manpages@gmail.com>
>> > Link: https://lkml.kernel.org/r/20180626132705.018623573@linutronix.de
>> > [florian: Make patch apply to v4.9.135]
>> > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> > ---
>> > Thomas, can you review for correctness? Thanks!
>>
>> Thomas, John, does that look like a reasonable backport for 4.9?
>
>Looks correct.
Queued for 4.9, thanks all.
--
Thanks,
Sasha
next prev parent reply other threads:[~2018-11-08 15:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-01 20:02 [PATCH stable 4.9] posix-timers: Sanitize overrun handling Florian Fainelli
2018-11-07 19:37 ` Florian Fainelli
2018-11-08 6:48 ` Thomas Gleixner
2018-11-08 15:46 ` Sasha Levin [this message]
2018-11-08 22:36 ` Florian Fainelli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181108154625.GC8097@sasha-vm \
--to=sashal@kernel.org \
--cc=f.fainelli@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mtk.manpages@gmail.com \
--cc=peterz@infradead.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.