From: Jeremy Compostella <jeremy.composte...@intel.com>
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 <mi...@kernel.org>
Reported-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Jeremy Compostella <jeremy.composte...@intel.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
[ Updated changelog to include gcc error ]
Signed-off-by: Matt Fleming <m...@codeblueprint.co.uk>
---
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 2e0c7ccd9d9e..8dd0c7085e59 100644
--- a/drivers/firmware/efi/efibc.c
+++ b/drivers/firmware/efi/efibc.c
@@ -17,6 +17,7 @@
#include <linux/efi.h>
#include <linux/module.h>
#include <linux/reboot.h>
+#include <linux/slab.h>
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);
--
2.7.3
