From: Breno Leitao <leitao@debian.org>
To: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>, Jens Axboe <axboe@kernel.dk>,
leit@meta.com,
"open list:CONTROL GROUP - BLOCK IO CONTROLLER (BLKIO)"
<cgroups@vger.kernel.org>,
"open list:CONTROL GROUP - BLOCK IO CONTROLLER (BLKIO)"
<linux-block@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] blk-iocost: Fix shift-out-of-bounds in iocg_kick_delay()
Date: Thu, 11 Apr 2024 06:33:02 -0700 [thread overview]
Message-ID: <Zhfmjoa2l04fXIVr@gmail.com> (raw)
In-Reply-To: <ZhbuUKXQwBwye1_r@slm.duckdns.org>
On Wed, Apr 10, 2024 at 09:53:52AM -1000, Tejun Heo wrote:
> Hello, Breno.
>
> On Wed, Apr 10, 2024 at 12:36:41PM -0700, Breno Leitao wrote:
> > When running iocg_kick_delay(), iocg->delay_at could be way behind "now",
> > which causes a huge tdelta difference.
> >
> > The tdelta value is used to shift some bits around, raising the
> > following UBSAN splat:
> >
> > UBSAN: shift-out-of-bounds in block/blk-iocost.c:1366:23
> >
> > Debugging this, these are some values I got in my machine with 6.9-rc3.
> >
> > now = 3626064295
> > iocg->delay_at = 3275794093
> >
> > Fix this by validating that the shift if valid, otherwise bail out,
> > similarly to commit 2a427b49d029 ("blk-iocost: Fix an UBSAN
> > shift-out-of-bounds warning")
>
> Rik alreaady sent a fix:
>
> http://lkml.kernel.org/r/20240404123253.0f58010f@imladris.surriel.com
>
> which got commited as beaa51b36012fad5a4d3c18b88a617aea7a9b96d.
Even easier then. Thanks!
prev parent reply other threads:[~2024-04-11 13:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-10 19:36 [PATCH] blk-iocost: Fix shift-out-of-bounds in iocg_kick_delay() Breno Leitao
2024-04-10 19:53 ` Tejun Heo
2024-04-11 13:33 ` Breno Leitao [this message]
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