This is a note to let you know that I've just added the patch titled mm: introduce clear_highpage_kasan_tagged to the 5.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-introduce-clear_highpage_kasan_tagged.patch and it can be found in the queue-5.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d9da8f6cf55eeca642c021912af1890002464c64 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Date: Thu, 9 Jun 2022 20:18:46 +0200 Subject: mm: introduce clear_highpage_kasan_tagged From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> commit d9da8f6cf55eeca642c021912af1890002464c64 upstream. Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a page potentially tagged by KASAN. This helper is used by the following patch. Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Jiri Slaby <jirislaby@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/highmem.h | 10 ++++++++++ mm/page_alloc.c | 8 ++------ 2 files changed, 12 insertions(+), 6 deletions(-) --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -243,6 +243,16 @@ static inline void clear_highpage(struct kunmap_local(kaddr); } +static inline void clear_highpage_kasan_tagged(struct page *page) +{ + u8 tag; + + tag = page_kasan_tag(page); + page_kasan_tag_reset(page); + clear_highpage(page); + page_kasan_tag_set(page, tag); +} + #ifndef __HAVE_ARCH_TAG_CLEAR_HIGHPAGE static inline void tag_clear_highpage(struct page *page) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1302,12 +1302,8 @@ static void kernel_init_free_pages(struc /* s390's use of memset() could override KASAN redzones. */ kasan_disable_current(); - for (i = 0; i < numpages; i++) { - u8 tag = page_kasan_tag(page + i); - page_kasan_tag_reset(page + i); - clear_highpage(page + i); - page_kasan_tag_set(page + i, tag); - } + for (i = 0; i < numpages; i++) + clear_highpage_kasan_tagged(page + i); kasan_enable_current(); } Patches currently in stable-queue which might be from andreyknvl@xxxxxxxxxx are queue-5.19/mm-introduce-clear_highpage_kasan_tagged.patch queue-5.19/arm64-stacktrace-use-non-atomic-__set_bit.patch queue-5.19/arm64-kasan-do-not-instrument-stacktrace.c.patch queue-5.19/kasan-fix-zeroing-vmalloc-memory-with-hw_tags.patch