diff --git a/fs_mgr/fs_mgr_verity.cpp b/fs_mgr/fs_mgr_verity.cpp index 30c9731d9..efe3fd629 100644 --- a/fs_mgr/fs_mgr_verity.cpp +++ b/fs_mgr/fs_mgr_verity.cpp @@ -31,6 +31,7 @@ #include #include +#include #include #include #include @@ -73,6 +74,8 @@ #define VERITY_KMSG_RESTART "dm-verity device corrupted" #define VERITY_KMSG_BUFSIZE 1024 +#define READ_BUF_SIZE 4096 + #define __STRINGIFY(x) #x #define STRINGIFY(x) __STRINGIFY(x) @@ -205,6 +208,16 @@ static int create_verity_device(struct dm_ioctl *io, char *name, int fd) return 0; } +static int destroy_verity_device(struct dm_ioctl *io, char *name, int fd) +{ + verity_ioctl_init(io, name, 0); + if (ioctl(fd, DM_DEV_REMOVE, io)) { + ERROR("Error removing device mapping (%s)", strerror(errno)); + return -1; + } + return 0; +} + static int get_verity_device_name(struct dm_ioctl *io, char *name, int fd, char **dev_name) { verity_ioctl_init(io, name, 0); @@ -606,6 +619,30 @@ out: return rc; } +static int read_partition(const char *path, uint64_t size) +{ + char buf[READ_BUF_SIZE]; + ssize_t size_read; + android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_CLOEXEC))); + + if (fd == -1) { + ERROR("Failed to open %s: %s\n", path, strerror(errno)); + return -errno; + } + + while (size) { + size_read = TEMP_FAILURE_RETRY(read(fd, buf, READ_BUF_SIZE)); + if (size_read == -1) { + ERROR("Error in reading partition %s: %s\n", path, + strerror(errno)); + return -errno; + } + size -= size_read; + } + + return 0; +} + static int compare_last_signature(struct fstab_rec *fstab, int *match) { char tag[METADATA_TAG_MAX_LENGTH + 1]; @@ -904,6 +941,7 @@ int fs_mgr_setup_verity(struct fstab_rec *fstab, bool verify_dev) alignas(dm_ioctl) char buffer[DM_BUF_SIZE]; struct dm_ioctl *io = (struct dm_ioctl *) buffer; char *mount_point = basename(fstab->mount_point); + bool verified_at_boot = false; if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE, FEC_DEFAULT_ROOTS) < 0) { @@ -1037,10 +1075,26 @@ loaded: // mark the underlying block device as read-only fs_mgr_set_blk_ro(fstab->blk_device); + // Verify the entire partition in one go + // If there is an error, allow it to mount as a normal verity partition. + if (fstab->fs_mgr_flags & MF_VERIFYATBOOT) { + INFO("Verifying partition %s at boot\n", fstab->blk_device); + int err = read_partition(verity_blk_name, verity.data_size); + if (!err) { + INFO("Verified verity partition %s at boot\n", fstab->blk_device); + verified_at_boot = true; + } + } + // assign the new verity block device as the block device - free(fstab->blk_device); - fstab->blk_device = verity_blk_name; - verity_blk_name = 0; + if (!verified_at_boot) { + free(fstab->blk_device); + fstab->blk_device = verity_blk_name; + verity_blk_name = 0; + } else if (destroy_verity_device(io, mount_point, fd) < 0) { + ERROR("Failed to remove verity device %s\n", mount_point); + goto out; + } // make sure we've set everything up properly if (verify_dev && test_access(fstab->blk_device) < 0) {