From: Thomas Gleixner <tglx@linutronix.de>
To: Elena Reshetova <elena.reshetova@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
peterz@infradead.org, gregkh@linuxfoundation.org,
viro@zeniv.linux.org.uk, tj@kernel.org, mingo@redhat.com,
hannes@cmpxchg.org, lizefan@huawei.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, eparis@redhat.com,
akpm@linux-foundation.org, arnd@arndb.de, luto@kernel.org,
keescook@chromium.org, dvhart@infradead.org,
ebiederm@xmission.com
Subject: Re: [PATCH 14/15] futex: convert futex_pi_state.refcount to refcount_t
Date: Fri, 1 Sep 2017 09:39:50 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.20.1709010939360.1857@nanos> (raw)
In-Reply-To: <1504095773-22895-15-git-send-email-elena.reshetova@intel.com>
On Wed, 30 Aug 2017, Elena Reshetova wrote:
> atomic_t variables are currently used to implement reference
> counters with the following properties:
> - counter is initialized to 1 using atomic_set()
> - a resource is freed upon counter reaching zero
> - once counter reaches zero, its further
> increments aren't allowed
> - counter schema uses basic atomic operations
> (set, inc, inc_not_zero, dec_and_test, etc.)
>
> Such atomic variables should be converted to a newly provided
> refcount_t type and API that prevents accidental counter overflows
> and underflows. This is important since overflows and underflows
> can lead to use-after-free situation and be exploitable.
>
> The variable futex_pi_state.refcount is used as pure
> reference counter. Convert it to refcount_t and fix up
> the operations.
>
> Suggested-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: David Windsor <dwindsor@gmail.com>
> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
next prev parent reply other threads:[~2017-09-01 7:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-30 12:22 [PATCH 00/15] v5 kernel core pieces refcount conversions Elena Reshetova
2017-08-30 12:22 ` [PATCH 01/15] sched: convert sighand_struct.count to refcount_t Elena Reshetova
2017-08-30 12:22 ` [PATCH 02/15] sched: convert signal_struct.sigcnt " Elena Reshetova
2017-08-30 12:22 ` [PATCH 03/15] sched: convert user_struct.__count " Elena Reshetova
2017-08-30 12:22 ` [PATCH 04/15] sched: convert numa_group.refcount " Elena Reshetova
2017-08-30 12:22 ` [PATCH 05/15] sched/task_struct: convert task_struct.usage " Elena Reshetova
2017-08-30 12:22 ` [PATCH 06/15] sched/task_struct: convert task_struct.stack_refcount " Elena Reshetova
2017-08-30 12:22 ` [PATCH 07/15] perf: convert perf_event_context.refcount " Elena Reshetova
2017-08-30 12:22 ` [PATCH 08/15] perf/ring_buffer: convert ring_buffer.refcount " Elena Reshetova
2017-08-30 12:22 ` [PATCH 09/15] perf/ring_buffer: convert ring_buffer.aux_refcount " Elena Reshetova
2017-08-30 12:22 ` [PATCH 10/15] uprobes: convert uprobe.ref " Elena Reshetova
2017-08-30 12:22 ` [PATCH 11/15] nsproxy: convert nsproxy.count " Elena Reshetova
2017-08-30 12:22 ` [PATCH 12/15] groups: convert group_info.usage " Elena Reshetova
2017-08-30 12:22 ` [PATCH 13/15] creds: convert cred.usage " Elena Reshetova
2017-08-30 12:22 ` [PATCH 14/15] futex: convert futex_pi_state.refcount " Elena Reshetova
2017-09-01 7:39 ` Thomas Gleixner [this message]
2017-09-01 9:38 ` Peter Zijlstra
2017-09-01 9:43 ` Thomas Gleixner
2017-09-01 10:52 ` Reshetova, Elena
2017-09-01 11:05 ` Reshetova, Elena
2017-09-01 12:34 ` Peter Zijlstra
2017-09-01 13:24 ` Reshetova, Elena
2017-09-01 13:36 ` Peter Zijlstra
2017-09-01 17:03 ` Reshetova, Elena
2017-09-01 19:12 ` Peter Zijlstra
2017-09-04 10:31 ` Reshetova, Elena
2017-09-04 12:00 ` Peter Zijlstra
2017-09-14 16:02 ` Reshetova, Elena
2017-10-20 12:03 ` Reshetova, Elena
2017-10-20 12:30 ` Thomas Gleixner
2017-10-23 7:36 ` Reshetova, Elena
2017-08-30 12:22 ` [PATCH 15/15] kcov: convert kcov.refcount " Elena Reshetova
2017-08-31 23:48 ` [PATCH 00/15] v5 kernel core pieces refcount conversions Kees Cook
2017-09-01 9:48 ` Peter Zijlstra
2017-09-01 16:55 ` Kees Cook
2017-09-01 17:08 ` Reshetova, Elena
-- strict thread matches above, loose matches on Subject: below --
2017-08-25 9:41 [PATCH 00/15] v4 " Elena Reshetova
2017-08-25 9:41 ` [PATCH 14/15] futex: convert futex_pi_state.refcount to refcount_t Elena Reshetova
2017-07-18 10:29 [PATCH 00/15] v4 kernel core pieces refcount conversions Elena Reshetova
2017-07-18 10:30 ` [PATCH 14/15] futex: convert futex_pi_state.refcount to refcount_t Elena Reshetova
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