zs_page_migrate() uses copy_page() to copy the contents of a zspage page during migration. However, copy_page() is not instrumented by KMSAN, so the shadow and origin metadata of the destination page are not updated. As a result, subsequent accesses to the migrated page are reported as use-after-free by KMSAN, despite the data being correctly copied. Add a kmsan_copy_page_meta() call after copy_page() to propagate the KMSAN metadata to the new page, matching what copy_highpage() does internally. Fixes: afb2d666d025 ("zsmalloc: use copy_page for full page copy") Signed-off-by: Shigeru Yoshida --- mm/zsmalloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 2c1430bf8d57..79ef9d57f2e1 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -1741,6 +1741,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page, */ d_addr = kmap_local_zpdesc(newzpdesc); copy_page(d_addr, s_addr); + kmsan_copy_page_meta(zpdesc_page(newzpdesc), zpdesc_page(zpdesc)); kunmap_local(d_addr); for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE; -- 2.52.0