From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
Dominik Brodowski <linux@dominikbrodowski.net>
Subject: Re: [PATCH 2/2] random: spread out jitter callback to different CPUs
Date: Fri, 7 Oct 2022 09:29:23 +0200 [thread overview]
Message-ID: <Yz/VU/FhdgspxFdh@linutronix.de> (raw)
In-Reply-To: <Yz8E0lSmsMMB6KeO@sultan-box.localdomain>
On 2022-10-06 09:39:46 [-0700], Sultan Alsawaf wrote:
> Hi Sebastian,
Hi Sultan,
> But since a timer is marked as not-pending prior to when it runs, add_timer_on()
> can't detect if the timer is actively running; the above BUG_ON() won't be
> tripped. So the UaF scenario I forsee is that doing this:
> add_timer_on(timer, 0);
> // timer is actively running on CPU0, timer is no longer pending
> add_timer_on(timer, 1); // changes timer base, won't wait for timer to stop
> del_timer_sync(timer); // only checks CPU1 timer base for the running timer
/me taking notes.
> Sultan
Sebastian
next prev parent reply other threads:[~2022-10-07 7:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-30 23:10 [PATCH 1/2] random: schedule jitter credit for next jiffy, not in two jiffies Jason A. Donenfeld
2022-09-30 23:10 ` [PATCH 2/2] random: spread out jitter callback to different CPUs Jason A. Donenfeld
2022-10-01 9:21 ` Jason A. Donenfeld
2022-10-05 17:26 ` Sebastian Andrzej Siewior
2022-10-05 21:08 ` Jason A. Donenfeld
2022-10-06 6:46 ` Sebastian Andrzej Siewior
2022-10-06 12:26 ` Jason A. Donenfeld
2022-10-06 12:41 ` Sebastian Andrzej Siewior
2022-10-06 16:39 ` Sultan Alsawaf
2022-10-07 7:29 ` Sebastian Andrzej Siewior [this message]
2022-10-07 14:01 ` Jason A. Donenfeld
2022-10-07 14:55 ` Sebastian Andrzej Siewior
2022-10-07 15:32 ` Jason A. Donenfeld
2022-11-29 16:08 ` [PATCH v2] " Jason A. Donenfeld
2022-11-29 18:27 ` [PATCH v3] " Jason A. Donenfeld
[not found] ` <20221130014514.6494-1-hdanton@sina.com>
2022-11-30 1:49 ` Jason A. Donenfeld
2022-11-30 18:48 ` [PATCH v4] " Jason A. Donenfeld
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