From: Geert Uytterhoeven <geert@linux-m68k.org>
To: SF Markus Elfring <elfring@users.sourceforge.net>
Cc: kvm@vger.kernel.org, linux-s390 <linux-s390@vger.kernel.org>,
"Christian Bornträger" <borntraeger@de.ibm.com>,
"Cornelia Huck" <cornelia.huck@de.ibm.com>,
"David Hildenbrand" <dahi@linux.vnet.ibm.com>,
"Heiko Carstens" <heiko.carstens@de.ibm.com>,
"Martin Schwidefsky" <schwidefsky@de.ibm.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>,
"Julia Lawall" <julia.lawall@lip6.fr>,
"Walter Harms" <wharms@bfs.de>
Subject: Re: [PATCH v2 2/2] KVM: s390: Use memdup_user() rather than duplicating code
Date: Mon, 3 Oct 2016 14:11:18 +0200 [thread overview]
Message-ID: <CAMuHMdVX6RKZYQyOrX35D+EKoRH6ZFAkyiC=BKnyKtE1Ph4t8g@mail.gmail.com> (raw)
In-Reply-To: <c86f7520-885e-2829-ae9c-b81caa898e84@users.sourceforge.net>
Hi Markus,
On Wed, Aug 24, 2016 at 8:40 PM, SF Markus Elfring
<elfring@users.sourceforge.net> wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 24 Aug 2016 20:10:09 +0200
>
> * Reuse existing functionality from memdup_user() instead of keeping
> duplicate source code.
>
> This issue was detected by using the Coccinelle software.
>
> * Return directly if this copy operation failed.
>
> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>
> v2: Rebased on source files from "Linux next-20160824".
>
> arch/s390/kvm/guestdbg.c | 18 ++++--------------
> 1 file changed, 4 insertions(+), 14 deletions(-)
>
> diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c
> index 70b71ac..d7c6a7f 100644
> --- a/arch/s390/kvm/guestdbg.c
> +++ b/arch/s390/kvm/guestdbg.c
> @@ -216,20 +216,10 @@ int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
> else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
> return -EINVAL;
>
> - bp_data = kmalloc_array(dbg->arch.nr_hw_bp,
> - sizeof(*bp_data),
> - GFP_KERNEL);
Probably not an issue here, but if "sizeof(*bp_data) * dbg->arch.nr_hw_bp"
overflows, kmalloc_array() would have returned NULL here...
> - if (!bp_data) {
> - ret = -ENOMEM;
> - goto error;
> - }
> -
> - if (copy_from_user(bp_data,
> - dbg->arch.hw_bp,
> - sizeof(*bp_data) * dbg->arch.nr_hw_bp)) {
> - ret = -EFAULT;
> - goto error;
> - }
> + bp_data = memdup_user(dbg->arch.hw_bp,
> + sizeof(*bp_data) * dbg->arch.nr_hw_bp);
... while this would continue silently, and corrupt memory.
> + if (IS_ERR(bp_data))
> + return PTR_ERR(bp_data);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2016-10-03 12:11 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-17 18:02 [PATCH 0/4] KVM-S390: Fine-tuning for kvm_s390_import_bp_data() SF Markus Elfring
2016-08-17 18:06 ` [PATCH 1/4] KVM-S390: Improve determination of sizes in kvm_s390_import_bp_data() SF Markus Elfring
2016-08-18 7:25 ` walter harms
2016-08-18 9:02 ` Julia Lawall
2016-08-18 9:48 ` Paolo Bonzini
2016-08-18 10:52 ` walter harms
2016-08-18 10:55 ` Paolo Bonzini
2016-08-22 12:58 ` Cornelia Huck
2016-08-24 12:10 ` Replacing specific kmalloc() calls by kmalloc_array()? SF Markus Elfring
2016-08-24 15:00 ` Paolo Bonzini
2016-08-17 18:08 ` [PATCH 2/4] KVM-S390: Use memdup_user() rather than duplicating its implementation SF Markus Elfring
2016-08-22 13:02 ` David Hildenbrand
2016-08-22 13:05 ` Cornelia Huck
2016-08-24 15:19 ` Christian Borntraeger
2016-08-24 18:30 ` [PATCH v2 0/2] KVM: s390: Fine-tuning for kvm_s390_import_bp_data() SF Markus Elfring
2016-08-24 18:36 ` [PATCH v2 1/2] KVM: s390: Improve determination of sizes in kvm_s390_import_bp_data() SF Markus Elfring
2016-08-25 16:10 ` Cornelia Huck
2016-08-25 16:45 ` SF Markus Elfring
2016-08-25 17:34 ` Software evolution around scripts for the semantic patch langugae SF Markus Elfring
2016-08-25 17:40 ` Cornelia Huck
2016-08-25 17:54 ` SF Markus Elfring
2016-08-25 18:14 ` Julia Lawall
2016-08-25 18:20 ` SF Markus Elfring
2016-08-25 18:23 ` Julia Lawall
2016-08-25 21:04 ` Cornelia Huck
2016-08-24 18:40 ` [PATCH v2 2/2] KVM: s390: Use memdup_user() rather than duplicating code SF Markus Elfring
2016-08-25 16:11 ` Cornelia Huck
2016-10-03 12:11 ` Geert Uytterhoeven [this message]
2016-10-03 12:28 ` SF Markus Elfring
2016-10-03 13:10 ` Geert Uytterhoeven
2016-10-03 13:47 ` SF Markus Elfring
2016-10-03 14:00 ` Geert Uytterhoeven
2016-10-03 14:25 ` SF Markus Elfring
2016-08-25 16:12 ` [PATCH v2 0/2] KVM: s390: Fine-tuning for kvm_s390_import_bp_data() Christian Borntraeger
2016-08-17 18:10 ` [PATCH 3/4] KVM-S390: Less function calls in kvm_s390_import_bp_data() after error detection SF Markus Elfring
2016-08-22 12:58 ` David Hildenbrand
2016-08-22 13:00 ` Cornelia Huck
2016-08-22 16:56 ` SF Markus Elfring
2016-08-22 19:37 ` Cornelia Huck
2016-08-22 21:17 ` SF Markus Elfring
2016-08-22 21:28 ` Cornelia Huck
2016-08-31 12:29 ` Paolo Bonzini
2016-08-24 15:10 ` Christian Borntraeger
2016-08-27 16:12 ` SF Markus Elfring
2016-08-17 18:12 ` [PATCH 4/4] KVM-S390: Delete an unnecessary initialisation for a buffer variable SF Markus Elfring
2016-08-22 12:59 ` David Hildenbrand
2016-08-22 13:01 ` Cornelia Huck
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