long running loops in grant table handling In order to...
Moderate severity
Unreviewed
Published
May 24, 2022
to the GitHub Advisory Database
•
Updated Jan 27, 2023
Description
Published by the National Vulnerability Database
Aug 27, 2021
Published to the GitHub Advisory Database
May 24, 2022
Last updated
Jan 27, 2023
long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.
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