From: David Laight <David.Laight@ACULAB.COM>
To: 'Elena Reshetova' <elena.reshetova@intel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: "peterz@infradead.org" <peterz@infradead.org>,
"matanb@mellanox.com" <matanb@mellanox.com>,
"paulus@samba.org" <paulus@samba.org>,
"nbd@openwrt.org" <nbd@openwrt.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"saeedm@mellanox.com" <saeedm@mellanox.com>,
"ganeshgr@chelsio.com" <ganeshgr@chelsio.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
David Windsor <dwindsor@gmail.com>,
"keescook@chromium.org" <keescook@chromium.org>,
"j@w1.fi" <j@w1.fi>,
"ajk@comnets.uni-bremen.de" <ajk@comnets.uni-bremen.de>,
"leonro@mellanox.com" <leonro@mellanox.com>,
"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
"linux-hams@vger.kernel.org" <linux-hams@vger.kernel.org>,
"kvalo@codeaurora.org" <kvalo@codeaurora.org>,
"blogic@openwrt.org" <blogic@openwrt.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-ppp@vger.kernel.org" <linux->
Subject: RE: [PATCH 06/16] drivers, net, mlx5: convert mlx5_cq.refcount from atomic_t to refcount_t
Date: Tue, 28 Mar 2017 09:33:21 +0000 [thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6DCFFBE8AF@AcuExch.aculab.com> (raw)
In-Reply-To: <1490691403-4016-7-git-send-email-elena.reshetova@intel.com>
From: Elena Reshetova
> Sent: 28 March 2017 09:57
>
> refcount_t type and corresponding API should be
> used instead of atomic_t when the variable is used as
> a reference counter. This allows to avoid accidental
> refcounter overflows that might lead to use-after-free
> situations.
I can't help feeling that you ought to find a scheme
that will detect extra decrements and extra increments
before the counter wraps 32 bits.
If an extra reference is requested every 100us it takes 4.8 days
for the counter to increment back to zero.
Simple tests aren't doing to find that - but it can easily happen
on a system that is running for several years.
David
next prev parent reply other threads:[~2017-03-28 9:33 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 8:56 [PATCH 00/16] Networking drivers refcount conversions Elena Reshetova
2017-03-28 8:56 ` [PATCH 01/16] drivers, net, ethernet: convert clip_entry.refcnt from atomic_t to refcount_t Elena Reshetova
2017-03-28 8:56 ` [PATCH 02/16] drivers, net, ethernet: convert mtk_eth.dma_refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 03/16] drivers, net, mlx4: convert mlx4_cq.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 04/16] drivers, net, mlx4: convert mlx4_qp.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 05/16] drivers, net, mlx4: convert mlx4_srq.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 06/16] drivers, net, mlx5: convert mlx5_cq.refcount " Elena Reshetova
2017-03-28 9:33 ` David Laight [this message]
2017-03-28 14:00 ` Reshetova, Elena
[not found] ` <1490691403-4016-1-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-03-28 8:56 ` [PATCH 07/16] drivers, net, mlx5: convert fs_node.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 08/16] drivers, net, hamradio: convert sixpack.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 09/16] drivers, net: convert masces_rx_sa.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 10/16] drivers, net: convert masces_rx_sc.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 11/16] drivers, net: convert masces_tx_sa.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 12/16] drivers, net, ppp: convert asyncppp.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 13/16] drivers, net, ppp: convert ppp_file.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 14/16] drivers, net, ppp: convert syncppp.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 15/16] drivers, net, intersil: convert hostap_cmd_queue.usecnt " Elena Reshetova
[not found] ` <1490691403-4016-16-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-03 11:38 ` [PATCH 15/16] drivers, net, intersil: convert hostap_cmd_queue.usecnt from atomic_t to refcount_ Kalle Valo
2017-05-22 15:24 ` [15/16] hostap: convert hostap_cmd_queue.usecnt from atomic_t to refcount_t Kalle Valo
2017-03-28 8:56 ` [PATCH 16/16] drivers, net, intersil: convert request_context.refcount " Elena Reshetova
2017-04-03 11:41 ` [PATCH 16/16] drivers, net, intersil: convert request_context.refcount from atomic_t to refcount Kalle Valo
2017-04-04 10:07 ` Reshetova, Elena
2017-04-05 10:33 ` Kalle Valo
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