From 1c3808f4b5249691d9e15ec8d268158d52c6d899 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 3 Feb 2015 11:38:22 +0100 Subject: [PATCH] IOMMU/x86: correct page_list_first() use Comparing its result against NULL is unsafe when page lists use normal list entries for linking together - page_list_empty() needs to be used instead. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper Reviewed-by: Tim Deegan --- xen/drivers/passthrough/x86/iommu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c index ce0ca5aa39..52d89482b8 100644 --- a/xen/drivers/passthrough/x86/iommu.c +++ b/xen/drivers/passthrough/x86/iommu.c @@ -85,8 +85,9 @@ int arch_iommu_populate_page_table(struct domain *d) * first few entries. */ page_list_move(&d->page_list, &d->arch.relmem_list); - while ( (page = page_list_first(&d->page_list)) != NULL && - (page->count_info & (PGC_state|PGC_broken)) ) + while ( !page_list_empty(&d->page_list) && + (page = page_list_first(&d->page_list), + (page->count_info & (PGC_state|PGC_broken))) ) { page_list_del(page, &d->page_list); page_list_add_tail(page, &d->arch.relmem_list); -- 2.30.2