From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f69.google.com (mail-oo1-f69.google.com [209.85.161.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C335F362137 for ; Fri, 3 Apr 2026 06:13:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775196836; cv=none; b=hDBvkExsxwLOoqgOu4/FfEOarslw1vbRr4nCH3iGRnWkCXiEeLcvU4Bnum8T5jYrFTivkrWMJ4OuB5mTl4FfKWwLDIbOBwuO0vsjt2PKucoCz2CjJGwGShyJ8fNn6tdwq/LraWVCghAfKRraeV3udjdRa7qLq0pBFRmOULoQ9TU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775196836; c=relaxed/simple; bh=1ZJxkk4HnV9UgLMq7YrZRWjmk/bbm9RG7//kQ1JvFWw=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=r0T6t9orUdL7oev7TUIk8Or3kq5LdCbVa/6wTcVhzPzTwGqeADPsc1atLIZoZfOIVKtt/FvnwYPaPOBgHMFlqvzEqSFtscLi2+zuOW7gL7AKXfJRpCY3Lg+Va6Ql7xBO/uBtG+9K7RLlmVBE7jmWuDdPArKC/2wjLlBJQe0Svlc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f69.google.com with SMTP id 006d021491bc7-682644bbbb5so552162eaf.2 for ; Thu, 02 Apr 2026 23:13:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775196827; x=1775801627; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mDFmeeifJRj/kQ91hTy9EXgcnEBVCUCCx9XI0DUsyxo=; b=dTESX64Z+FK9sWMv/TkGVg8NqMKkUXu3Zs5h1SM2HuPg+LtTG1qvmcBa9QyNLj4XUv 1v9/FRg7on9N2eijKITu2wg8mNneIlGtMvkjZrURCwmJ+Iz/8tUFfEkS5HpHoyHDQr1W ghNOjr3inBjIWvOLpK6HFduT6/N2SzvAa+/GChvsGjUrJ3C+qPvscjhQjHkU0Ky74EBg H+Km0MUnvd9KBMQT+wNrmjb9AvSHR+Wz9I0BYWjRJWWi2w7ykTsNUiVBm7JgborFUQR4 YLcaPgFqzDMQX/dInzsEKYui4/2rstNvbEdt3dtD7gIpegwdHO8WfI98bA7+X5Js4gfg 60eQ== X-Forwarded-Encrypted: i=1; AJvYcCXQan+SVGlUxZQW+zADciGJqrFnlZBD/NxSi6HAT+pNdWJZsYB5yC1ghM/oFnD6V15E1ix6P8+WAauu5pk=@vger.kernel.org X-Gm-Message-State: AOJu0Yz/igW7umrN2wXeXJ8zL/RpnLcQCLVvd1Uu+5gloAwckoqNVl1S ZuSPMhAMTmDUXuzdfNSQnJFj3QR3xWwlH2c1wiqe/8OY7RgXYS5D/6vMt2s5N82jDtDog7UI2KJ oU8qm4k5CBOEVVUVFAqPfgZb4L+wieb50gfElcs9jIQMeC2iW+efd9q6WxVc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2e45:b0:67e:4004:dc88 with SMTP id 006d021491bc7-6821f67b438mr694446eaf.40.1775196827024; Thu, 02 Apr 2026 23:13:47 -0700 (PDT) Date: Thu, 02 Apr 2026 23:13:47 -0700 In-Reply-To: X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69cf5a9b.050a0220.182279.000e.GAE@google.com> Subject: Re: [syzbot] KMSAN: uninit-value in follow_page_pte From: syzbot To: ke.zhao.kernel@gmail.com Cc: ke.zhao.kernel@gmail.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" > #syz test This crash does not have a reproducer. I cannot test it. > > This is a test patch to fix the KMSAN uninit-value in follow_page_pte. > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5189,6 +5189,10 @@ unsigned long alloc_pages_bulk_noprof(gfp_t gfp, > int preferred_nid, > > prep_new_page(page, 0, gfp, 0); > set_page_refcounted(page); > + > + trace_mm_page_alloc(page, 0, gfp, ac.migratetype); > + kmsan_alloc_page(page, 0, gfp); > + > page_array[nr_populated++] = page; > } > > @@ -6911,6 +6915,12 @@ static void split_free_frozen_pages(struct > list_head *list, gfp_t gfp_mask) > int i; > > post_alloc_hook(page, order, gfp_mask); > + /* > + * Initialize KMSAN state right after > post_alloc_hook(). > + * This prepares the pages for subsequent outer > callers > + * that might free sub-pages after the split. > + */ > + kmsan_alloc_page(page, order, gfp_mask); > if (!order) > continue; > > @@ -7117,6 +7127,8 @@ int alloc_contig_frozen_range_noprof(unsigned long > start, unsigned long end, > > check_new_pages(head, order); > prep_new_page(head, order, gfp_mask, 0); > + > + kmsan_alloc_page(head, order, gfp_mask); > } else { > ret = -EINVAL; > WARN(true, "PFN range: requested [%lu, %lu), allocated > [%lu, %lu)\n", >