From: Keqian Zhu <zhukeqian1@huawei.com>
To: Eric Auger <eric.auger@redhat.com>, <eric.auger.pro@gmail.com>,
<linux-kernel@vger.kernel.org>, <kvm@vger.kernel.org>,
<kvmarm@lists.cs.columbia.edu>, <maz@kernel.org>,
<alexandru.elisei@arm.com>, <suzuki.poulose@arm.com>,
<james.morse@arm.com>
Cc: <drjones@redhat.com>, <gshan@redhat.com>
Subject: Re: [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
Date: Tue, 13 Apr 2021 14:05:47 +0800 [thread overview]
Message-ID: <d458c821-75a3-a22a-67b0-19b6201cd6ca@huawei.com> (raw)
In-Reply-To: <20210412150034.29185-1-eric.auger@redhat.com>
On 2021/4/12 23:00, Eric Auger wrote:
> When reading the base address of the a REDIST region
> through KVM_VGIC_V3_ADDR_TYPE_REDIST we expect the
> redistributor region list to be populated with a single
> element.
>
> However list_first_entry() expects the list to be non empty.
Indeed, list_first_entry() always return a non-null ptr. If the list
is empty, it will mistake the list head as the first element.
> Instead we should use list_first_entry_or_null which effectively
> returns NULL if the list is empty.
>
> Fixes: dbd9733ab674 ("KVM: arm/arm64: Replace the single rdist region by a list")
> Cc: <Stable@vger.kernel.org> # v4.18+
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Reported-by: Gavin Shan <gshan@redhat.com>
> ---
> arch/arm64/kvm/vgic/vgic-kvm-device.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
> index 44419679f91a..5eaede3e3b5a 100644
> --- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
> +++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
> @@ -87,8 +87,8 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> r = vgic_v3_set_redist_base(kvm, 0, *addr, 0);
> goto out;
> }
> - rdreg = list_first_entry(&vgic->rd_regions,
> - struct vgic_redist_region, list);
> + rdreg = list_first_entry_or_null(&vgic->rd_regions,
> + struct vgic_redist_region, list);
> if (!rdreg)
> addr_ptr = &undef_value;
> else
>
next prev parent reply other threads:[~2021-04-13 6:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 15:00 [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read Eric Auger
2021-04-13 6:05 ` Keqian Zhu [this message]
2021-04-13 14:05 ` Marc Zyngier
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d458c821-75a3-a22a-67b0-19b6201cd6ca@huawei.com \
--to=zhukeqian1@huawei.com \
--cc=alexandru.elisei@arm.com \
--cc=drjones@redhat.com \
--cc=eric.auger.pro@gmail.com \
--cc=eric.auger@redhat.com \
--cc=gshan@redhat.com \
--cc=james.morse@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).