[xen stable-4.20] xen/page_alloc: scrub each page in unprepare_staticmem_pages

[patchbot@xxxxxxx]

commit a4cbbb704f9b9551eccd8ee50d293773d1d45ce5
Author:     Peter Kang <peter.kang@xxxxxxxxxx>
AuthorDate: Thu Oct 29 13:34:39 2026 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Oct 29 13:34:39 2026 +0100

    xen/page_alloc: scrub each page in unprepare_staticmem_pages
    
    unprepare_staticmem_pages() can unprepare multiple pages in a static
    memory range. When need_scrub is true, each page must be scrubbed
    before it is marked static.
    
    The loop currently passes the base pointer pg to scrub_one_page() on
    every iteration. For a multi-page range, this repeatedly scrubs page 0
    and leaves the remaining pages unscrubbed, so a guest can later read
    stale data from pages 1..nr_mfns-1 of a static or static-shared bank.
    
    Pass &pg[i] to scrub_one_page() so each iteration scrubs the page it
    is processing. This ensures every page in the range is scrubbed before
    it is marked static.
    
    Fixes: 4a9e73e6e53e ("xen/arm: static memory initialization")
    Signed-off-by: Peter Kang <peter.kang@xxxxxxxxxx>
    master commit: 65f523e546c88765096629647315db850cae8553
    master date: 2026-10-27 09:02:42 +0100
---
 xen/common/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 2682fff9cc..426bd11c2e 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -2941,7 +2941,7 @@ void unprepare_staticmem_pages(struct page_info *pg, 
unsigned long nr_mfns,
         if ( need_scrub )
         {
             /* TODO: asynchronous scrubbing for pages of static memory. */
-            scrub_one_page(pg);
+            scrub_one_page(&pg[i]);
         }
 
         pg[i].count_info |= PGC_static;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.20