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Ian Campbell authored
The caller will not undo a mapping which failed and therefore the override will not be removed. This is especially bad in the case of GNTMAP_contains_pte mapping type mappings where m2p_add_override will destroy the kernel mapping of the page. This was observed via a failure of map_grant_pages in gntdev_mmap (due to userspace using a bad grant reference), which left the page in question unmapped (because it was a GNTMAP_contains_pte mapping) which led to a crash later on. Signed-off-by:
Ian Campbell <ian.campbell@citrix.com> Cc: Daniel De Graaf <dgdegra@tycho.nsa.gov> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
dc4972a4