From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757526AbdELV7B (ORCPT ); Fri, 12 May 2017 17:59:01 -0400 Received: from mail-pg0-f47.google.com ([74.125.83.47]:36099 "EHLO mail-pg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755920AbdELV66 (ORCPT ); Fri, 12 May 2017 17:58:58 -0400 Date: Fri, 12 May 2017 14:58:54 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Anton Vorontsov , Colin Cross , Tony Luck , Matt Fleming , Ard Biesheuvel , Seiji Aguchi , Geliang Tang , linux-efi@vger.kernel.org Subject: [PATCH] efi-pstore: Fix read iter after pstore API refactor Message-ID: <20170512215854.GA85220@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During the internal pstore API refactoring, the EFI vars read entry was accidentally made to update a stack variable instead of the pstore private data pointer. This corrects the problem (and removes the now needless argument). Signed-off-by: Kees Cook --- drivers/firmware/efi/efi-pstore.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c index 93d8cdbe7ef4..9e6f14c354f1 100644 --- a/drivers/firmware/efi/efi-pstore.c +++ b/drivers/firmware/efi/efi-pstore.c @@ -155,25 +155,20 @@ static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos, * efi_pstore_sysfs_entry_iter * * @record: pstore record to pass to callback - * @pos: entry to begin iterating from * * You MUST call efivar_enter_iter_begin() before this function, and * efivar_entry_iter_end() afterwards. * - * It is possible to begin iteration from an arbitrary entry within - * the list by passing @pos. @pos is updated on return to point to - * the next entry of the last one passed to efi_pstore_read_func(). - * To begin iterating from the beginning of the list @pos must be %NULL. */ -static int efi_pstore_sysfs_entry_iter(struct pstore_record *record, - struct efivar_entry **pos) +static int efi_pstore_sysfs_entry_iter(struct pstore_record *record) { + struct efivar_entry *pos = (struct efivar_entry *)record->psi->data; struct efivar_entry *entry, *n; struct list_head *head = &efivar_sysfs_list; int size = 0; int ret; - if (!*pos) { + if (!pos) { list_for_each_entry_safe(entry, n, head, list) { efi_pstore_scan_sysfs_enter(entry, n, head); @@ -185,21 +180,21 @@ static int efi_pstore_sysfs_entry_iter(struct pstore_record *record, if (size) break; } - *pos = n; + pos = n; return size; } - list_for_each_entry_safe_from((*pos), n, head, list) { - efi_pstore_scan_sysfs_enter((*pos), n, head); + list_for_each_entry_safe_from(pos, n, head, list) { + efi_pstore_scan_sysfs_enter(pos, n, head); - size = efi_pstore_read_func((*pos), record); - ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0); + size = efi_pstore_read_func(pos, record); + ret = efi_pstore_scan_sysfs_exit(pos, n, head, size < 0); if (ret) return ret; if (size) break; } - *pos = n; + pos = n; return size; } @@ -218,7 +213,6 @@ static int efi_pstore_sysfs_entry_iter(struct pstore_record *record, */ static ssize_t efi_pstore_read(struct pstore_record *record) { - struct efivar_entry *entry = (struct efivar_entry *)record->psi->data; ssize_t size; record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL); @@ -229,7 +223,7 @@ static ssize_t efi_pstore_read(struct pstore_record *record) size = -EINTR; goto out; } - size = efi_pstore_sysfs_entry_iter(record, &entry); + size = efi_pstore_sysfs_entry_iter(record); efivar_entry_iter_end(); out: -- 2.7.4 -- Kees Cook Pixel Security