From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CD44C433E5 for ; Mon, 22 Mar 2021 12:39:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 335CD619B6 for ; Mon, 22 Mar 2021 12:39:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231374AbhCVMja (ORCPT ); Mon, 22 Mar 2021 08:39:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:57626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231561AbhCVMe0 (ORCPT ); Mon, 22 Mar 2021 08:34:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 07C93619B0; Mon, 22 Mar 2021 12:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616416466; bh=Vs9X3DWpoNzidoByjxNF39t5YA8bOyKNWwrGousiYhg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QMqAEIc9SEhjTjI2k4qsCUHTSplWmWCGCBYYwCSQEHFgxYUOhLCKCeQHettUQoHo4 frTlgN7qFdi8bQm0Mh94s/YbxAdoe0eMz1UUjJT7RtII7cFXyS1h18zV8MNYuL176A 4CFvWUIGCGTWXnMl6geX6evYjQ7tx/G9PSArACMs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lv Yunlong , Ard Biesheuvel Subject: [PATCH 5.11 118/120] firmware/efi: Fix a use after bug in efi_mem_reserve_persistent Date: Mon, 22 Mar 2021 13:28:21 +0100 Message-Id: <20210322121933.603602456@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121929.669628946@linuxfoundation.org> References: <20210322121929.669628946@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lv Yunlong commit 9ceee7d0841a8f7d7644021ba7d4cc1fbc7966e3 upstream. In the for loop in efi_mem_reserve_persistent(), prsv = rsv->next use the unmapped rsv. Use the unmapped pages will cause segment fault. Fixes: 18df7577adae6 ("efi/memreserve: deal with memreserve entries in unmapped memory") Signed-off-by: Lv Yunlong Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/efi/efi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -927,7 +927,7 @@ int __ref efi_mem_reserve_persistent(phy } /* first try to find a slot in an existing linked list entry */ - for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) { + for (prsv = efi_memreserve_root->next; prsv; ) { rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB); index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size); if (index < rsv->size) { @@ -937,6 +937,7 @@ int __ref efi_mem_reserve_persistent(phy memunmap(rsv); return efi_mem_reserve_iomem(addr, size); } + prsv = rsv->next; memunmap(rsv); }