Re: [PATCH] i40e{,vf}: Fix out-of-bound cpumask read in IRQ affinity handler

On Tue, 15 Aug 2017 12:30:14 +0200
Stefano Brivio [off-list ref] wrote:

The cpumask used in i40e{,vf}_irq_affinity_notify() is allocated
by irq_affinity_notify() with alloc_cpumask_var(), which doesn't
allocate NR_CPUS bits, but only nr_cpumask_bits bits. If we just
dereference it, we'll read way more than what is allocated, e.g.
1024 bytes vs. 8 bytes allocated on x86_64 machine with 24 CPUs.

Sorry, just two minutes after sending this I noticed Juergen submitted
the same fixes on Saturday:

From: Juergen Gross <jgross@suse.com>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,         intel-wired-lan@lists.osuosl.org
Cc: jeffrey.t.kirsher@intel.com, Juergen Gross <jgross@suse.com>,         stable@vger.kernel.org
Subject: [PATCH] net/i40e: use cpumask_copy() for assigning cpumask
Date: Sat, 12 Aug 2017 18:09:46 +0200

Please discard.