The EFI spec does not provide a length limit for variables.
Reviewed-by: Alexander Graf agraf@suse.de Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- v2: no change --- lib/efi_loader/efi_variable.c | 52 ++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 22 deletions(-)
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 770c67abb9..495738884b 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -44,10 +44,7 @@ * converted to utf16? */
-#define MAX_VAR_NAME 31 -#define MAX_NATIVE_VAR_NAME \ - (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx_") + \ - (MAX_VAR_NAME * MAX_UTF8_PER_UTF16)) +#define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx_"))
static int hex(int ch) { @@ -101,18 +98,20 @@ static char *mem2hex(char *hexstr, const u8 *mem, int count) return hexstr; }
-static efi_status_t efi_to_native(char *native, u16 *variable_name, +static efi_status_t efi_to_native(char **native, const u16 *variable_name, efi_guid_t *vendor) { size_t len; + char *pos;
- len = u16_strlen((u16 *)variable_name); - if (len >= MAX_VAR_NAME) - return EFI_DEVICE_ERROR; + len = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1; + *native = malloc(len); + if (!*native) + return EFI_OUT_OF_RESOURCES;
- native += sprintf(native, "efi_%pUl_", vendor); - native = (char *)utf16_to_utf8((u8 *)native, (u16 *)variable_name, len); - *native = '\0'; + pos = *native; + pos += sprintf(pos, "efi_%pUl_", vendor); + utf16_utf8_strcpy(&pos, variable_name);
return EFI_SUCCESS; } @@ -168,7 +167,7 @@ efi_status_t EFIAPI efi_get_variable(u16 *variable_name, efi_guid_t *vendor, u32 *attributes, efi_uintn_t *data_size, void *data) { - char native_name[MAX_NATIVE_VAR_NAME + 1]; + char *native_name; efi_status_t ret; unsigned long in_size; const char *val, *s; @@ -180,13 +179,14 @@ efi_status_t EFIAPI efi_get_variable(u16 *variable_name, efi_guid_t *vendor, if (!variable_name || !vendor || !data_size) return EFI_EXIT(EFI_INVALID_PARAMETER);
- ret = efi_to_native(native_name, variable_name, vendor); + ret = efi_to_native(&native_name, variable_name, vendor); if (ret) return EFI_EXIT(ret);
debug("%s: get '%s'\n", __func__, native_name);
val = env_get(native_name); + free(native_name); if (!val) return EFI_EXIT(EFI_NOT_FOUND);
@@ -256,35 +256,41 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor, u32 attributes, efi_uintn_t data_size, void *data) { - char native_name[MAX_NATIVE_VAR_NAME + 1]; + char *native_name = NULL, *val = NULL, *s; efi_status_t ret = EFI_SUCCESS; - char *val, *s; u32 attr;
EFI_ENTRY(""%ls" %pUl %x %zu %p", variable_name, vendor, attributes, data_size, data);
- if (!variable_name || !vendor) - return EFI_EXIT(EFI_INVALID_PARAMETER); + if (!variable_name || !vendor) { + ret = EFI_INVALID_PARAMETER; + goto out; + }
- ret = efi_to_native(native_name, variable_name, vendor); + ret = efi_to_native(&native_name, variable_name, vendor); if (ret) - return EFI_EXIT(ret); + goto out;
#define ACCESS_ATTR (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)
if ((data_size == 0) || !(attributes & ACCESS_ATTR)) { /* delete the variable: */ env_set(native_name, NULL); - return EFI_EXIT(EFI_SUCCESS); + ret = EFI_SUCCESS; + goto out; }
val = env_get(native_name); if (val) { parse_attr(val, &attr);
- if (attr & READ_ONLY) - return EFI_EXIT(EFI_WRITE_PROTECTED); + if (attr & READ_ONLY) { + /* We should not free val */ + val = NULL; + ret = EFI_WRITE_PROTECTED; + goto out; + } }
val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1); @@ -320,6 +326,8 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor, if (env_set(native_name, val)) ret = EFI_DEVICE_ERROR;
+out: + free(native_name); free(val);
return EFI_EXIT(ret);