From: Paolo Bonzini <pbonzini@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 1.0] qiov: prevent double free or use-after-free
Date: Fri, 25 Nov 2011 12:55:21 +0100 [thread overview]
Message-ID: <4ECF8229.8000805@redhat.com> (raw)
In-Reply-To: <4ECF8264.7020606@redhat.com>
On 11/25/2011 12:56 PM, Kevin Wolf wrote:
>> qemu_iovec_destroy does not clear the QEMUIOVector fully, and the data
>> > could thus be used after free or freed again. While I do not know any
>> > example in the tree, I observed this using virtio-scsi (and SCSI
>> > scatter/gather) when canceling DMA requests.
>> >
>> > Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> This isn't a bug fix for itself, it just makes bugs in other code more
> visible, right? It probably makes sense to do this change, but I'm not
> sure about doing it for 1.0.
It is a fix. NULLing the pointer prevents double-free bugs, and setting
niov/nalloc to 0 should prevent use-after-free.
Paolo
prev parent reply other threads:[~2011-11-25 11:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-25 11:06 [Qemu-devel] [PATCH 1.0] qiov: prevent double free or use-after-free Paolo Bonzini
2011-11-25 11:56 ` Kevin Wolf
2011-11-25 11:55 ` Paolo Bonzini [this message]
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