bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

mm/zsmalloc: copy KMSAN metadata in zs_page_migrate()

Browse Source 
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.

Link: https://lkml.kernel.org/r/20260321132912.93434-1-syoshida@redhat.com
Fixes: afb2d666d0 ("zsmalloc: use copy_page for full page copy")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Shigeru Yoshida
2026-03-21 22:29:11 +09:00
committed by Andrew Morton
parent 1871d548fc
commit 4fb61d95ad
1 changed files with 1 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
mm/zsmalloc.c
View File

@@ -1753,6 +1753,7 @@ 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;