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Re: [Qemu-devel] [PATCH 1/2] ehci: apply limit to itd/sidt descriptors
From: |
P J P |
Subject: |
Re: [Qemu-devel] [PATCH 1/2] ehci: apply limit to itd/sidt descriptors |
Date: |
Mon, 18 Apr 2016 17:22:48 +0530 (IST) |
+-- On Mon, 18 Apr 2016, Gerd Hoffmann wrote --+
| Commit "156a2e4 ehci: make idt processing more robust" tries to avoid a
| DoS by the guest (create a circular itd queue and let qemu ehci
| emulation run in circles forever). Unfortunaly this has two problems:
| First it misses the case of sitds, and second it reportly breaks
| freebsd.
|
| So lets go for a different approach: just count the number of itds and
| sitds we have seen per frame and apply a limit. That should really
| catch all cases now.
idt -> iTD
sidt -> siTD
Unfortualy -> Unfortunately
reportly -> reportedly
freebsd -> FreeBSD
Perhaps it'll help to add "Fixes: 156a2e4(CVE-2015-8558)" to the commit log?
(just a thought)
Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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