From nobody Mon May 25 05:56:13 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (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 559EA37F8AD for ; Mon, 18 May 2026 03:20:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779074430; cv=none; b=r9JXCNJwINw7qK1fo6uYz+7jdffxltP+RQy9tVvOgkJ37olRnbyRVZFeAFr8gNPFG5cwNwMfoPBGM/lBkb+FWFQyRuUgi3HldbOl1k/xgi9XMkz0CeGcZaxWmf9xaj1TX4mEeCLKN6mR7cKvacCF5N99101cu3jVVbWtc7Bc5lc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779074430; c=relaxed/simple; bh=MIcHR7uSPbg5opCMszI3lIjK5Icy0smfS5X6B487r+M=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=c+Bk8GyvG+c0E3LStKs+YxBqC4HugUxYwfdY7aNguZbqJWC9yMsUN/m068RtRrM/KtVUiwwGbfGzvIzOBWqeFg3B439k6jOTzEyaYyE6nNJQrbMrx3rKqLH120j8UjxLMPzppQeBUpVqGgUVxoEQbdsBs6XrQEIBwEUhLj1TRi0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=Rw3p6pZd; arc=none smtp.client-ip=220.197.31.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="Rw3p6pZd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=+R 2QSJwrWBhgomsPY/Bqp55QXOlThKM5lqu+wyxBYXw=; b=Rw3p6pZdzxxy43lJso pCrRvtQuTDjkatshsKUYINRTCP32ixJdNw1D7VcAeMa3WSOUlx+dtvmttpUmfxG9 xCpVD99BmKQZgj4DhDKPqV/TEcKS7o7r031Yb7RkWTZ075K8sedR7GYPx8uLyolH xA/AOIWk1KXdGbIr6NMI3THnw= Received: from neo-TianYi510Pro-15ICK.. (unknown []) by gzsmtp5 (Coremail) with SMTP id QCgvCgDHb8Q_hQpqOhDIEA--.18582S2; Mon, 18 May 2026 11:19:30 +0800 (CST) From: liuqiangneo@163.com To: apopple@nvidia.com, jgg@ziepe.ca, leon@kernel.org, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qiang Liu Subject: [PATCH v2] lib/test_hmm: Check alloc_page_vma() return value Date: Mon, 18 May 2026 11:19:03 +0800 Message-ID: <20260518031903.63455-1-liuqiangneo@163.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: QCgvCgDHb8Q_hQpqOhDIEA--.18582S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrtw17XrWDJFW3tw48uw48WFg_yoWkuFc_ur 4UA3Z0gFy5JF98GF1rtws7JrWFkwsF9FWxu3Z5trW3ua4YvrsFga1DXrsxJa9xGa109FW7 CrWDAr1fZr9IyjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU1pwZDUUUUU== X-CM-SenderInfo: 5olx1xxdqj0vrr6rljoofrz/xtbC+wOO72oKhUP-4AAA3g Content-Type: text/plain; charset="utf-8" From: Qiang Liu Return VM_FAULT_OOM if page allocation fails, which avoids a NULL pointer dereference when calling lock_page(). Signed-off-by: Qiang Liu --- v2: - Add unlock and free allocated pages before return. - https://lore.kernel.org/all/20260514032345.32256-1-liuqiangneo@163.com/ --- lib/test_hmm.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 213504915737..90aec4ca2e01 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -1063,6 +1063,17 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_cop= y(struct migrate_vma *args, /* Try with smaller pages if large allocation fails */ if (!dpage && order) { dpage =3D alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr); + if (!dpage) { + /* Unlock and free pages already allocated. */ + while (i > 0) { + struct page *fpage; + + fpage =3D migrate_pfn_to_page(dst[--i]); + unlock_page(fpage); + __free_page(fpage); + } + return VM_FAULT_OOM; + } lock_page(dpage); dst[i] =3D migrate_pfn(page_to_pfn(dpage)); dst_page =3D pfn_to_page(page_to_pfn(dpage)); --=20 2.43.0