[SRU Focal 4/6] x86/mm: Recompute physical address for every page of per-CPU CEA mapping

[Cengiz Can]

From: Sean Christopherson <seanjc at google.com>

Recompute the physical address for each per-CPU page in the CPU entry
area, a recent commit inadvertantly modified cea_map_percpu_pages() such
that every PTE is mapped to the physical address of the first page.

Fixes: 9fd429c28073 ("x86/kasan: Map shadow for percpu pages on demand")
Signed-off-by: Sean Christopherson <seanjc at google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Reviewed-by: Andrey Ryabinin <ryabinin.a.a at gmail.com>
Link: https://lkml.kernel.org/r/20221110203504.1985010-2-seanjc@google.com
(cherry picked from commit 80d72a8f76e8f3f0b5a70b8c7022578e17bde8e7)
CVE-2023-0597
[cengizcan: fixes the prerequisite commit]
Signed-off-by: Cengiz Can <cengiz.can at canonical.com>
---
 arch/x86/mm/cpu_entry_area.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index e7a201f3fa65..bfd8f15e6b59 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -97,7 +97,7 @@ cea_map_percpu_pages(void *cea_vaddr, void *ptr, int pages, pgprot_t prot)
 					early_pfn_to_nid(PFN_DOWN(pa)));
 
 	for ( ; pages; pages--, cea_vaddr+= PAGE_SIZE, ptr += PAGE_SIZE)
-		cea_set_pte(cea_vaddr, pa, prot);
+		cea_set_pte(cea_vaddr, per_cpu_ptr_to_phys(ptr), prot);
 }
 
 static void __init percpu_setup_debug_store(unsigned int cpu)
-- 
2.39.2