linux-kernel - Re: [PATCH 2/3] KVM: Stop looking for coalesced MMIO zones if the bus is destroyed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALMp9eSQuDXg4nU0xmD7VHFnWpvsqGJ1SLudTf0nzx+nggk7DA@mail.gmail.com>
Date:   Thu, 15 Apr 2021 15:22:19 -0700
From:   Jim Mattson <jmattson@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        kvm list <kvm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Hao Sun <sunhao.th@...il.com>
Subject: Re: [PATCH 2/3] KVM: Stop looking for coalesced MMIO zones if the bus
 is destroyed

On Mon, Apr 12, 2021 at 3:21 PM Sean Christopherson <seanjc@...gle.com> wrote:
>
> Abort the walk of coalesced MMIO zones if kvm_io_bus_unregister_dev()
> fails to allocate memory for the new instance of the bus.  If it can't
> instantiate a new bus, unregister_dev() destroys all devices _except_ the
> target device.   But, it doesn't tell the caller that it obliterated the
> bus and invoked the destructor for all devices that were on the bus.  In
> the coalesced MMIO case, this can result in a deleted list entry
> dereference due to attempting to continue iterating on coalesced_zones
> after future entries (in the walk) have been deleted.
>
> Opportunistically add curly braces to the for-loop, which encompasses
> many lines but sneaks by without braces due to the guts being a single
> if statement.
>
> Fixes: f65886606c2d ("KVM: fix memory leak in kvm_io_bus_unregister_dev()")
> Cc: stable@...r.kernel.org
> Reported-by: Hao Sun <sunhao.th@...il.com>
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>
Reviewed-by: Jim Mattson <jmattson@...gle.com>