From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D1AD2E8B81; Thu, 12 Feb 2026 23:44:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770939872; cv=none; b=rEhB7PuAGOcirbonP1RleXy7jMb/4eVWMgeg4EIr5hyXmfHdL3xM3rqPM6nlRmNEYVlMV7YqsD8n6xsjKdNDz8Cf/JZBfqtV2FMvveMP9RFmxRPObDalZnx6m27uBN7hl5Rwuxa1gar0boVuEw61NN+9kFN7PHCcGF4SZnmNU2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770939872; c=relaxed/simple; bh=qW0RZrgvKKG6wUB5z+KzsiFjuiRYucR3Xh8F8iKeirg=; h=Date:To:From:Subject:Message-Id; b=R3yLr6u4j2jOg8afYxp+c8CANiYG5Er2YGGiw27UAO4S7eYRJxSIxBFjt14ABcBjrB2oMV5q9Ak2ApSmtQDAM5/GusIvbPvDlv0NpmfuXo0IICsj/In8zAsaeVfLbr/0XGBY3BKp1GAy9mIP1ZTeoA+SAi/U4HJYlJe4YZbKNKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=1rOC/5+z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="1rOC/5+z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EEF8C4CEF7; Thu, 12 Feb 2026 23:44:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1770939872; bh=qW0RZrgvKKG6wUB5z+KzsiFjuiRYucR3Xh8F8iKeirg=; h=Date:To:From:Subject:From; b=1rOC/5+zp2FmNokLDaotcsK2nJcfOrUNo2MM4i2QATVM0z2uosnxu5Ezs28Gzyl6S 41s86XpmkTqg1ff6Bx1pKmvdWS7vLCisj8CJDlEU4K/7gcB1e0CcvVU+rnjvsJ+v79 FRxiVXhJgpHUeoCctnC4dWeherjsSO4Fo85zcwVg= Date: Thu, 12 Feb 2026 15:44:31 -0800 To: mm-commits@vger.kernel.org,ziy@nvidia.com,willy@infradead.org,vbabka@suse.cz,surenb@google.com,stable@vger.kernel.org,ryncsn@gmail.com,npiggin@gmail.com,mhocko@suse.com,jackmanb@google.com,hughd@google.com,hannes@cmpxchg.org,david@kernel.org,chrisl@kernel.org,mikhail.v.gavrilov@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-page_alloc-clear-page-private-in-free_pages_prepare.patch removed from -mm tree Message-Id: <20260212234432.0EEF8C4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/page_alloc: clear page->private in free_pages_prepare() has been removed from the -mm tree. Its filename was mm-page_alloc-clear-page-private-in-free_pages_prepare.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Mikhail Gavrilov Subject: mm/page_alloc: clear page->private in free_pages_prepare() Date: Sat, 7 Feb 2026 22:36:14 +0500 Several subsystems (slub, shmem, ttm, etc.) use page->private but don't clear it before freeing pages. When these pages are later allocated as high-order pages and split via split_page(), tail pages retain stale page->private values. This causes a use-after-free in the swap subsystem. The swap code uses page->private to track swap count continuations, assuming freshly allocated pages have page->private == 0. When stale values are present, swap_count_continued() incorrectly assumes the continuation list is valid and iterates over uninitialized page->lru containing LIST_POISON values, causing a crash: KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107] RIP: 0010:__do_sys_swapoff+0x1151/0x1860 Fix this by clearing page->private in free_pages_prepare(), ensuring all freed pages have clean state regardless of previous use. Link: https://lkml.kernel.org/r/20260207173615.146159-1-mikhail.v.gavrilov@gmail.com Fixes: 3b8000ae185c ("mm/vmalloc: huge vmalloc backing pages should be split rather than compound") Signed-off-by: Mikhail Gavrilov Suggested-by: Zi Yan Acked-by: Zi Yan Acked-by: David Hildenbrand (Arm) Reviewed-by: Vlastimil Babka Cc: Brendan Jackman Cc: Chris Li Cc: Hugh Dickins Cc: Johannes Weiner Cc: Kairui Song Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Nicholas Piggin Cc: Suren Baghdasaryan Cc: Signed-off-by: Andrew Morton --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/page_alloc.c~mm-page_alloc-clear-page-private-in-free_pages_prepare +++ a/mm/page_alloc.c @@ -1429,6 +1429,7 @@ __always_inline bool free_pages_prepare( page_cpupid_reset_last(page); page->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP; + page->private = 0; reset_page_owner(page, order); page_table_check_free(page, order); pgalloc_tag_sub(page, 1 << order); _ Patches currently in -mm which might be from mikhail.v.gavrilov@gmail.com are