From: zerons <zeronsaxm@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Alexander Popov <alex.popov@linux.com>,
Andrey Konovalov <andreyknvl@google.com>,
kernel-hardening@lists.openwall.com,
Shawn <citypw@hardenedlinux.org>,
spender@grsecurity.net
Subject: Re: Maybe inappropriate use BUG_ON() in CONFIG_SLAB_FREELIST_HARDENED
Date: Tue, 18 Feb 2020 10:21:47 +0800 [thread overview]
Message-ID: <dc337497-8084-915c-be64-059ef7cc1538@gmail.com> (raw)
In-Reply-To: <202002171019.A7B4679@keescook>
>
>>> In my opinion, this patch can somehow help attacker exploit this kind of bugs
>>> more reliable.
>
> Why do you think this makes races easier to win?
>
Sorry, not to make the races easier, but to make the exploitations
more reliable.
>> +Alexander Popov, who is the author of the double free check in
>> SLAB_FREELIST_HARDENED.
>>
>> Ah, so as long as the double free happens in a user process context,
>> you can retry triggering it until you succeed in winning the race to
>> reallocate the object (without causing slab freelist corruption, as it
>> would have had happened before SLAB_FREELIST_HARDENED). Nice idea!
>
> Do you see improvements that could be made here?
>
Could we use BUG_ON() only when panic_on_oops is set?
next prev parent reply other threads:[~2020-02-18 11:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-13 15:16 Maybe inappropriate use BUG_ON() in CONFIG_SLAB_FREELIST_HARDENED zerons
2020-02-17 15:15 ` Andrey Konovalov
2020-02-17 18:23 ` Kees Cook
2020-02-18 2:21 ` zerons [this message]
2020-02-18 20:54 ` Alexander Popov
2020-02-19 13:43 ` zerons
2020-02-27 11:28 ` Alexander Popov
2020-03-08 0:44 ` zerons
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