Fix verity on system partitions larger than 2G

If the system partition is larger than 2G, the device fails to read
verity metadata, because fseek accepts only a 32-bit signed offset.
Switch from fseek to lseek64 to allow seeking using a 64-bit offset,
which solves the problem. At the same time, move away from stdio in
the function.

Bug: 17705619
Change-Id: I226320498dcb750ec6cde84411c7fe0774c9cab7
This commit is contained in:
Sami Tolvanen 2014-10-24 15:41:59 -07:00
parent 47a919c6fb
commit 4cafe2ff89

View file

@ -122,28 +122,28 @@ static int get_target_device_size(char *blk_device, uint64_t *device_size)
struct ext4_super_block sb; struct ext4_super_block sb;
struct fs_info info = {0}; struct fs_info info = {0};
data_device = open(blk_device, O_RDONLY); data_device = TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC));
if (data_device < 0) { if (data_device == -1) {
ERROR("Error opening block device (%s)", strerror(errno)); ERROR("Error opening block device (%s)", strerror(errno));
return -1; return -1;
} }
if (lseek64(data_device, 1024, SEEK_SET) < 0) { if (TEMP_FAILURE_RETRY(lseek64(data_device, 1024, SEEK_SET)) < 0) {
ERROR("Error seeking to superblock"); ERROR("Error seeking to superblock");
close(data_device); TEMP_FAILURE_RETRY(close(data_device));
return -1; return -1;
} }
if (read(data_device, &sb, sizeof(sb)) != sizeof(sb)) { if (TEMP_FAILURE_RETRY(read(data_device, &sb, sizeof(sb))) != sizeof(sb)) {
ERROR("Error reading superblock"); ERROR("Error reading superblock");
close(data_device); TEMP_FAILURE_RETRY(close(data_device));
return -1; return -1;
} }
ext4_parse_sb(&sb, &info); ext4_parse_sb(&sb, &info);
*device_size = info.len; *device_size = info.len;
close(data_device); TEMP_FAILURE_RETRY(close(data_device));
return 0; return 0;
} }
@ -153,13 +153,13 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab
unsigned table_length; unsigned table_length;
uint64_t device_length; uint64_t device_length;
int protocol_version; int protocol_version;
FILE *device; int device;
int retval = FS_MGR_SETUP_VERITY_FAIL; int retval = FS_MGR_SETUP_VERITY_FAIL;
*signature = 0; *signature = 0;
*table = 0; *table = 0;
device = fopen(block_device, "r"); device = TEMP_FAILURE_RETRY(open(block_device, O_RDONLY | O_CLOEXEC));
if (!device) { if (device == -1) {
ERROR("Could not open block device %s (%s).\n", block_device, strerror(errno)); ERROR("Could not open block device %s (%s).\n", block_device, strerror(errno));
goto out; goto out;
} }
@ -169,13 +169,14 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab
ERROR("Could not get target device size.\n"); ERROR("Could not get target device size.\n");
goto out; goto out;
} }
if (fseek(device, device_length, SEEK_SET) < 0) { if (TEMP_FAILURE_RETRY(lseek64(device, device_length, SEEK_SET)) < 0) {
ERROR("Could not seek to start of verity metadata block.\n"); ERROR("Could not seek to start of verity metadata block.\n");
goto out; goto out;
} }
// check the magic number // check the magic number
if (!fread(&magic_number, sizeof(int), 1, device)) { if (TEMP_FAILURE_RETRY(read(device, &magic_number, sizeof(magic_number))) !=
sizeof(magic_number)) {
ERROR("Couldn't read magic number!\n"); ERROR("Couldn't read magic number!\n");
goto out; goto out;
} }
@ -195,7 +196,8 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab
} }
// check the protocol version // check the protocol version
if (!fread(&protocol_version, sizeof(int), 1, device)) { if (TEMP_FAILURE_RETRY(read(device, &protocol_version,
sizeof(protocol_version))) != sizeof(protocol_version)) {
ERROR("Couldn't read verity metadata protocol version!\n"); ERROR("Couldn't read verity metadata protocol version!\n");
goto out; goto out;
} }
@ -205,39 +207,41 @@ static int read_verity_metadata(char *block_device, char **signature, char **tab
} }
// get the signature // get the signature
*signature = (char*) malloc(RSANUMBYTES * sizeof(char)); *signature = (char*) malloc(RSANUMBYTES);
if (!*signature) { if (!*signature) {
ERROR("Couldn't allocate memory for signature!\n"); ERROR("Couldn't allocate memory for signature!\n");
goto out; goto out;
} }
if (!fread(*signature, RSANUMBYTES, 1, device)) { if (TEMP_FAILURE_RETRY(read(device, *signature, RSANUMBYTES)) != RSANUMBYTES) {
ERROR("Couldn't read signature from verity metadata!\n"); ERROR("Couldn't read signature from verity metadata!\n");
goto out; goto out;
} }
// get the size of the table // get the size of the table
if (!fread(&table_length, sizeof(int), 1, device)) { if (TEMP_FAILURE_RETRY(read(device, &table_length, sizeof(table_length))) !=
sizeof(table_length)) {
ERROR("Couldn't get the size of the verity table from metadata!\n"); ERROR("Couldn't get the size of the verity table from metadata!\n");
goto out; goto out;
} }
// get the table + null terminator // get the table + null terminator
table_length += 1; *table = malloc(table_length + 1);
*table = malloc(table_length); if (!*table) {
if(!*table) {
ERROR("Couldn't allocate memory for verity table!\n"); ERROR("Couldn't allocate memory for verity table!\n");
goto out; goto out;
} }
if (!fgets(*table, table_length, device)) { if (TEMP_FAILURE_RETRY(read(device, *table, table_length)) !=
(ssize_t)table_length) {
ERROR("Couldn't read the verity table from metadata!\n"); ERROR("Couldn't read the verity table from metadata!\n");
goto out; goto out;
} }
(*table)[table_length] = 0;
retval = FS_MGR_SETUP_VERITY_SUCCESS; retval = FS_MGR_SETUP_VERITY_SUCCESS;
out: out:
if (device) if (device != -1)
fclose(device); TEMP_FAILURE_RETRY(close(device));
if (retval != FS_MGR_SETUP_VERITY_SUCCESS) { if (retval != FS_MGR_SETUP_VERITY_SUCCESS) {
free(*table); free(*table);