Message ID | 20210226105640.12037-2-julien@xen.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | xen/iommu: Collection of bug fixes for IOMMU teardown | expand |
On 26.02.2021 11:56, Julien Grall wrote: > From: Julien Grall <jgrall@amazon.com> > > When using CONFIG_BIGMEM=y, the page_list cannot be accessed whilst it > is is unitialized. However, iommu_free_pgtables() will be called even if > the domain is not using an IOMMU. > > Consequently, Xen will try to go through the page list and deference a > NULL pointer. > > Bail out early if the domain is not using an IOMMU. > > Fixes: 15bc9a1ef51c ("x86/iommu: add common page-table allocator") > Signed-off-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c index cea1032b3d02..58a330e82247 100644 --- a/xen/drivers/passthrough/x86/iommu.c +++ b/xen/drivers/passthrough/x86/iommu.c @@ -267,6 +267,9 @@ int iommu_free_pgtables(struct domain *d) struct page_info *pg; unsigned int done = 0; + if ( !is_iommu_enabled(d) ) + return 0; + while ( (pg = page_list_remove_head(&hd->arch.pgtables.list)) ) { free_domheap_page(pg);