Merge branch 'efi-vars' from Matthew Garrett
* efi-vars: efivars: Improve variable validation
This commit is contained in:
commit
65e62b502b
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@ -192,18 +192,21 @@ utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
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}
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static bool
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validate_device_path(struct efi_variable *var, int match, u8 *buffer, int len)
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validate_device_path(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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struct efi_generic_dev_path *node;
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int offset = 0;
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node = (struct efi_generic_dev_path *)buffer;
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while (offset < len) {
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offset += node->length;
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if (len < sizeof(*node))
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return false;
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if (offset > len)
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return false;
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while (offset <= len - sizeof(*node) &&
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node->length >= sizeof(*node) &&
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node->length <= len - offset) {
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offset += node->length;
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if ((node->type == EFI_DEV_END_PATH ||
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node->type == EFI_DEV_END_PATH2) &&
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@ -222,7 +225,8 @@ validate_device_path(struct efi_variable *var, int match, u8 *buffer, int len)
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}
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static bool
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validate_boot_order(struct efi_variable *var, int match, u8 *buffer, int len)
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validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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/* An array of 16-bit integers */
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if ((len % 2) != 0)
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@ -232,19 +236,27 @@ validate_boot_order(struct efi_variable *var, int match, u8 *buffer, int len)
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}
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static bool
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validate_load_option(struct efi_variable *var, int match, u8 *buffer, int len)
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validate_load_option(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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u16 filepathlength;
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int i, desclength = 0;
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int i, desclength = 0, namelen;
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namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
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/* Either "Boot" or "Driver" followed by four digits of hex */
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for (i = match; i < match+4; i++) {
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if (hex_to_bin(var->VariableName[i] & 0xff) < 0)
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if (var->VariableName[i] > 127 ||
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hex_to_bin(var->VariableName[i] & 0xff) < 0)
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return true;
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}
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/* A valid entry must be at least 6 bytes */
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if (len < 6)
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/* Reject it if there's 4 digits of hex and then further content */
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if (namelen > match + 4)
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return false;
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/* A valid entry must be at least 8 bytes */
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if (len < 8)
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return false;
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filepathlength = buffer[4] | buffer[5] << 8;
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@ -253,7 +265,7 @@ validate_load_option(struct efi_variable *var, int match, u8 *buffer, int len)
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* There's no stored length for the description, so it has to be
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* found by hand
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*/
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desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len) + 2;
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desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
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/* Each boot entry must have a descriptor */
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if (!desclength)
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@ -275,7 +287,8 @@ validate_load_option(struct efi_variable *var, int match, u8 *buffer, int len)
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}
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static bool
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validate_uint16(struct efi_variable *var, int match, u8 *buffer, int len)
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validate_uint16(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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/* A single 16-bit integer */
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if (len != 2)
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@ -285,7 +298,8 @@ validate_uint16(struct efi_variable *var, int match, u8 *buffer, int len)
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}
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static bool
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validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, int len)
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validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
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unsigned long len)
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{
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int i;
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@ -303,7 +317,7 @@ validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, int len)
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struct variable_validate {
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char *name;
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bool (*validate)(struct efi_variable *var, int match, u8 *data,
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int len);
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unsigned long len);
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};
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static const struct variable_validate variable_validate[] = {
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@ -325,7 +339,7 @@ static const struct variable_validate variable_validate[] = {
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};
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static bool
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validate_var(struct efi_variable *var, u8 *data, int len)
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validate_var(struct efi_variable *var, u8 *data, unsigned long len)
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{
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int i;
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u16 *unicode_name = var->VariableName;
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