From: Theodore Ts'o <tytso@mit.edu>
To: Michael Schmitz <schmitzmic@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-m68k@vger.kernel.org
Subject: Re: [RFC] fix race in drivers/char/random.c:get_reg()
Date: Wed, 24 May 2017 17:42:28 -0400 [thread overview]
Message-ID: <20170524214228.u5xysvdalferoxw5@thunk.org> (raw)
In-Reply-To: <1493538561-5075-1-git-send-email-schmitzmic@gmail.com>
On Sun, Apr 30, 2017 at 07:49:21PM +1200, Michael Schmitz wrote:
> get_reg() can be reentered on architectures with prioritized interrupts
> (m68k in this case), causing f->reg_index to be incremented after the
> range check. Out of bounds memory access past the pt_regs struct results.
> This will go mostly undetected unless access is beyond end of memory.
>
> Prevent the race by disabling interrupts in get_reg().
>
> Tested on m68k (Atari Falcon, and ARAnyM emulator).
>
> Kudos to Geert Uytterhoeven for helping to trace this race.
>
> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Thanks, applied. It will go to Linus shortly.
- Ted
prev parent reply other threads:[~2017-05-24 21:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-30 7:49 [RFC] fix race in drivers/char/random.c:get_reg() Michael Schmitz
2017-05-12 7:16 ` Geert Uytterhoeven
2017-05-24 21:42 ` Theodore Ts'o [this message]
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