From: Michal Hocko <mhocko@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
David Rientjes <rientjes@google.com>,
Mel Gorman <mgorman@suse.de>,
Johannes Weiner <hannes@cmpxchg.org>,
Al Viro <viro@zeniv.linux.org.uk>, Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Anton Vorontsov <anton@enomsg.org>,
Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Ben Skeggs <bskeggs@redhat.com>,
Kent Overstreet <kent.overstreet@gmail.com>,
Santosh Raspatur <santosh@chelsio.com>,
Hariprasad S <hariprasad@chelsio.com>,
Tariq Toukan <tariqt@mellanox.com>,
Yishai Hadas <yishaih@mellanox.com>,
Dan Williams <dan.j.williams@intel.com>,
Oleg Drokin <oleg.drokin@intel.com>,
Andreas Dilger <andreas.dilger@intel.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Sterba <dsterba@suse.com>, "Yan, Zheng" <zyan@redhat.com>,
Ilya Dryomov <idryomov@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Network Development <netdev@vger.kernel.org>
Subject: Re: [PATCH 5/6] treewide: use kv[mz]alloc* rather than opencoded variants
Date: Thu, 12 Jan 2017 18:37:46 +0100 [thread overview]
Message-ID: <20170112173745.GC31509@dhcp22.suse.cz> (raw)
In-Reply-To: <CAGXu5jKhYP=5YNuntzmG64WL92F59VKhByOh9nqaGP7-LBEnng@mail.gmail.com>
On Thu 12-01-17 09:26:09, Kees Cook wrote:
> On Thu, Jan 12, 2017 at 7:37 AM, Michal Hocko <mhocko@kernel.org> wrote:
[...]
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 4f74511015b8..e6bbb33d2956 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -1126,10 +1126,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
> > if (args->count < 1 || args->count > KVM_S390_SKEYS_MAX)
> > return -EINVAL;
> >
> > - keys = kmalloc_array(args->count, sizeof(uint8_t),
> > - GFP_KERNEL | __GFP_NOWARN);
> > - if (!keys)
> > - keys = vmalloc(sizeof(uint8_t) * args->count);
> > + keys = kvmalloc(args->count * sizeof(uint8_t), GFP_KERNEL);
>
> Before doing this conversion, can we add a kvmalloc_array() API? This
> conversion could allow for the reintroduction of integer overflow
> flaws. (This particular situation isn't at risk since ->count is
> checked, but I'd prefer we not create a risky set of examples for
> using kvmalloc.)
Well, I am not opposed to kvmalloc_array but I would argue that this
conversion cannot introduce new overflow issues. The code would have
to be broken already because even though kmalloc_array checks for the
overflow but vmalloc fallback doesn't...
If there is a general interest for this API I can add it.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2017-01-12 17:38 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 15:37 [PATCH 0/6 v3] kvmalloc Michal Hocko
2017-01-12 15:37 ` [PATCH 1/6] mm: introduce kv[mz]alloc helpers Michal Hocko
2017-01-16 4:34 ` John Hubbard
2017-01-16 8:47 ` Michal Hocko
2017-01-16 19:09 ` John Hubbard
2017-01-16 19:40 ` Michal Hocko
2017-01-16 21:15 ` John Hubbard
2017-01-16 21:48 ` Michal Hocko
2017-01-16 21:57 ` John Hubbard
2017-01-17 7:51 ` Michal Hocko
2017-01-18 5:59 ` John Hubbard
2017-01-18 8:21 ` Michal Hocko
2017-01-19 8:37 ` John Hubbard
2017-01-19 8:45 ` Michal Hocko
2017-01-19 9:09 ` John Hubbard
2017-01-19 9:56 ` Michal Hocko
2017-01-19 21:28 ` John Hubbard
2017-01-26 12:09 ` Michal Hocko
2017-01-30 8:42 ` Vlastimil Babka
2017-01-12 15:37 ` [PATCH 2/6] mm: support __GFP_REPEAT in kvmalloc_node for >=64kB Michal Hocko
2017-01-12 16:12 ` Michael S. Tsirkin
2017-01-14 2:42 ` Tetsuo Handa
2017-01-14 8:45 ` Michal Hocko
2017-01-24 15:40 ` Michael S. Tsirkin
2017-01-12 15:37 ` [PATCH 3/6] rhashtable: simplify a strange allocation pattern Michal Hocko
2017-01-12 15:37 ` [PATCH 4/6] ila: " Michal Hocko
2017-01-12 15:37 ` [PATCH 5/6] treewide: use kv[mz]alloc* rather than opencoded variants Michal Hocko
2017-01-12 15:57 ` David Sterba
2017-01-12 16:05 ` Christian Borntraeger
2017-01-12 16:54 ` Ilya Dryomov
2017-01-12 17:18 ` Michal Hocko
2017-01-12 17:00 ` Dan Williams
2017-01-12 17:26 ` Kees Cook
2017-01-12 17:37 ` Michal Hocko [this message]
2017-01-20 13:41 ` Vlastimil Babka
2017-01-24 15:00 ` Michal Hocko
2017-01-25 11:15 ` Vlastimil Babka
2017-01-25 13:09 ` Michal Hocko
2017-01-25 13:40 ` Ilya Dryomov
2017-01-12 17:29 ` Michal Hocko
2017-01-14 3:01 ` Tetsuo Handa
2017-01-14 8:49 ` Michal Hocko
2017-01-12 20:14 ` Boris Ostrovsky
2017-01-13 1:11 ` Dilger, Andreas
2017-01-14 10:56 ` Leon Romanovsky
2017-01-16 7:33 ` Michal Hocko
2017-01-16 8:28 ` Leon Romanovsky
2017-01-16 8:18 ` Tariq Toukan
2017-01-12 15:37 ` [RFC PATCH 6/6] net: use kvmalloc with __GFP_REPEAT rather than open coded variant Michal Hocko
2017-01-24 15:17 ` [PATCH 0/6 v3] kvmalloc Michal Hocko
2017-01-24 16:00 ` Eric Dumazet
2017-01-25 13:10 ` Michal Hocko
2017-01-24 19:17 ` Alexei Starovoitov
2017-01-25 13:10 ` Michal Hocko
2017-01-25 13:21 ` Michal Hocko
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