From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752644AbcEGGfU (ORCPT ); Sat, 7 May 2016 02:35:20 -0400 Received: from terminus.zytor.com ([198.137.202.10]:44138 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751113AbcEGGfR (ORCPT ); Sat, 7 May 2016 02:35:17 -0400 Date: Fri, 6 May 2016 23:34:07 -0700 From: tip-bot for Jeremy Compostella Message-ID: Cc: dvlasenk@redhat.com, ard.biesheuvel@linaro.org, hpa@zytor.com, matt@codeblueprint.co.uk, brgerst@gmail.com, arnd@arndb.de, bp@alien8.de, peterz@infradead.org, torvalds@linux-foundation.org, tglx@linutronix.de, luto@amacapital.net, linux-kernel@vger.kernel.org, mingo@kernel.org, jeremy.compostella@intel.com Reply-To: dvlasenk@redhat.com, hpa@zytor.com, ard.biesheuvel@linaro.org, brgerst@gmail.com, matt@codeblueprint.co.uk, torvalds@linux-foundation.org, tglx@linutronix.de, arnd@arndb.de, bp@alien8.de, peterz@infradead.org, luto@amacapital.net, mingo@kernel.org, linux-kernel@vger.kernel.org, jeremy.compostella@intel.com In-Reply-To: <1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk> References: <1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk> To: linux-tip-commits@vger.kernel.org Subject: [tip:efi/core] efibc: Fix excessive stack footprint warning Git-Commit-ID: 2e121d711a51f91e792595a05cf9ef6963cb8464 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2e121d711a51f91e792595a05cf9ef6963cb8464 Gitweb: http://git.kernel.org/tip/2e121d711a51f91e792595a05cf9ef6963cb8464 Author: Jeremy Compostella AuthorDate: Fri, 6 May 2016 22:39:28 +0100 Committer: Ingo Molnar CommitDate: Sat, 7 May 2016 07:06:13 +0200 efibc: Fix excessive stack footprint warning GCC complains about a newly added file for the EFI Bootloader Control: drivers/firmware/efi/efibc.c: In function 'efibc_set_variable': drivers/firmware/efi/efibc.c:53:1: error: the frame size of 2272 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] The problem is the declaration of a local variable of type struct efivar_entry, which is by itself larger than the warning limit of 1024 bytes. Use dynamic memory allocation instead of stack memory for the entry object. This patch also fixes a potential buffer overflow. Reported-by: Ingo Molnar Reported-by: Arnd Bergmann Signed-off-by: Jeremy Compostella [ Updated changelog to include GCC error ] Signed-off-by: Matt Fleming Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar --- drivers/firmware/efi/efibc.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/firmware/efi/efibc.c b/drivers/firmware/efi/efibc.c index 2e0c7cc..8dd0c70 100644 --- a/drivers/firmware/efi/efibc.c +++ b/drivers/firmware/efi/efibc.c @@ -17,6 +17,7 @@ #include #include #include +#include static void efibc_str_to_str16(const char *str, efi_char16_t *str16) { @@ -28,41 +29,52 @@ static void efibc_str_to_str16(const char *str, efi_char16_t *str16) str16[i] = '\0'; } -static void efibc_set_variable(const char *name, const char *value) +static int efibc_set_variable(const char *name, const char *value) { int ret; efi_guid_t guid = LINUX_EFI_LOADER_ENTRY_GUID; - struct efivar_entry entry; + struct efivar_entry *entry; size_t size = (strlen(value) + 1) * sizeof(efi_char16_t); - if (size > sizeof(entry.var.Data)) + if (size > sizeof(entry->var.Data)) { pr_err("value is too large"); + return -EINVAL; + } - efibc_str_to_str16(name, entry.var.VariableName); - efibc_str_to_str16(value, (efi_char16_t *)entry.var.Data); - memcpy(&entry.var.VendorGuid, &guid, sizeof(guid)); + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) { + pr_err("failed to allocate efivar entry"); + return -ENOMEM; + } - ret = efivar_entry_set(&entry, + efibc_str_to_str16(name, entry->var.VariableName); + efibc_str_to_str16(value, (efi_char16_t *)entry->var.Data); + memcpy(&entry->var.VendorGuid, &guid, sizeof(guid)); + + ret = efivar_entry_set(entry, EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, - size, entry.var.Data, NULL); + size, entry->var.Data, NULL); if (ret) pr_err("failed to set %s EFI variable: 0x%x\n", name, ret); + + kfree(entry); + return ret; } static int efibc_reboot_notifier_call(struct notifier_block *notifier, unsigned long event, void *data) { const char *reason = "shutdown"; + int ret; if (event == SYS_RESTART) reason = "reboot"; - efibc_set_variable("LoaderEntryRebootReason", reason); - - if (!data) + ret = efibc_set_variable("LoaderEntryRebootReason", reason); + if (ret || !data) return NOTIFY_DONE; efibc_set_variable("LoaderEntryOneShot", (char *)data);