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authorJeremy Compostella <[email protected]>2016-05-06 22:39:28 +0100
committerIngo Molnar <[email protected]>2016-05-07 07:06:13 +0200
commit2e121d711a51f91e792595a05cf9ef6963cb8464 (patch)
tree510005d33d6a005fc980a78134a116e55c11c23c
parent62075e581802ea1842d5d3c490a7e46330bdb9e1 (diff)
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 <[email protected]> Reported-by: Arnd Bergmann <[email protected]> Signed-off-by: Jeremy Compostella <[email protected]> [ Updated changelog to include GCC error ] Signed-off-by: Matt Fleming <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--drivers/firmware/efi/efibc.c34
1 files 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);