From: Dmitry Kasatkin Date: Wed, 5 Nov 2014 15:01:12 +0000 (+0200) Subject: integrity: define a new function integrity_read_file() X-Git-Tag: firefly_0821_release~176^2~2675^2~2^2~5 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e3c4abbfa97ed0b7aed36f18b32911ccf76d52c2;p=firefly-linux-kernel-4.4.55.git integrity: define a new function integrity_read_file() This patch defines a new function called integrity_read_file() to read file from the kernel into a buffer. Subsequent patches will read a file containing the public keys and load them onto the IMA keyring. This patch moves and renames ima_kernel_read(), the non-security checking version of kernel_read(), to integrity_kernel_read(). Changes in v3: * Patch descriptions improved (Mimi) * Add missing cast (kbuild test robot) Changes in v2: * configuration option removed * function declared as '__init' Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- diff --git a/security/integrity/iint.c b/security/integrity/iint.c index cc3eb4de18a1..dbee618526b6 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include #include "integrity.h" static struct rb_root integrity_iint_tree = RB_ROOT; @@ -167,3 +169,79 @@ static int __init integrity_iintcache_init(void) return 0; } security_initcall(integrity_iintcache_init); + + +/* + * integrity_kernel_read - read data from the file + * + * This is a function for reading file content instead of kernel_read(). + * It does not perform locking checks to ensure it cannot be blocked. + * It does not perform security checks because it is irrelevant for IMA. + * + */ +int integrity_kernel_read(struct file *file, loff_t offset, + char *addr, unsigned long count) +{ + mm_segment_t old_fs; + char __user *buf = (char __user *)addr; + ssize_t ret = -EINVAL; + + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + + old_fs = get_fs(); + set_fs(get_ds()); + if (file->f_op->read) + ret = file->f_op->read(file, buf, count, &offset); + else if (file->f_op->aio_read) + ret = do_sync_read(file, buf, count, &offset); + else if (file->f_op->read_iter) + ret = new_sync_read(file, buf, count, &offset); + set_fs(old_fs); + return ret; +} + +/* + * integrity_read_file - read entire file content into the buffer + * + * This is function opens a file, allocates the buffer of required + * size, read entire file content to the buffer and closes the file + * + * It is used only by init code. + * + */ +int __init integrity_read_file(const char *path, char **data) +{ + struct file *file; + loff_t size; + char *buf; + int rc = -EINVAL; + + file = filp_open(path, O_RDONLY, 0); + if (IS_ERR(file)) { + rc = PTR_ERR(file); + pr_err("Unable to open file: %s (%d)", path, rc); + return rc; + } + + size = i_size_read(file_inode(file)); + if (size <= 0) + goto out; + + buf = kmalloc(size, GFP_KERNEL); + if (!buf) { + rc = -ENOMEM; + goto out; + } + + rc = integrity_kernel_read(file, 0, buf, size); + if (rc < 0) + kfree(buf); + else if (rc != size) + rc = -EIO; + else + *data = buf; +out: + fput(file); + return rc; +} diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index d34e7dfc1118..5df4d960d4dc 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -67,36 +67,6 @@ MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); static struct crypto_shash *ima_shash_tfm; static struct crypto_ahash *ima_ahash_tfm; -/** - * ima_kernel_read - read file content - * - * This is a function for reading file content instead of kernel_read(). - * It does not perform locking checks to ensure it cannot be blocked. - * It does not perform security checks because it is irrelevant for IMA. - * - */ -static int ima_kernel_read(struct file *file, loff_t offset, - char *addr, unsigned long count) -{ - mm_segment_t old_fs; - char __user *buf = addr; - ssize_t ret = -EINVAL; - - if (!(file->f_mode & FMODE_READ)) - return -EBADF; - - old_fs = get_fs(); - set_fs(get_ds()); - if (file->f_op->read) - ret = file->f_op->read(file, buf, count, &offset); - else if (file->f_op->aio_read) - ret = do_sync_read(file, buf, count, &offset); - else if (file->f_op->read_iter) - ret = new_sync_read(file, buf, count, &offset); - set_fs(old_fs); - return ret; -} - int __init ima_init_crypto(void) { long rc; @@ -324,7 +294,8 @@ static int ima_calc_file_hash_atfm(struct file *file, } /* read buffer */ rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]); - rc = ima_kernel_read(file, offset, rbuf[active], rbuf_len); + rc = integrity_kernel_read(file, offset, rbuf[active], + rbuf_len); if (rc != rbuf_len) goto out3; @@ -417,7 +388,7 @@ static int ima_calc_file_hash_tfm(struct file *file, while (offset < i_size) { int rbuf_len; - rbuf_len = ima_kernel_read(file, offset, rbuf, PAGE_SIZE); + rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE); if (rbuf_len < 0) { rc = rbuf_len; break; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index f51ad65c894d..20d220481025 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -119,6 +119,10 @@ struct integrity_iint_cache { */ struct integrity_iint_cache *integrity_iint_find(struct inode *inode); +int integrity_kernel_read(struct file *file, loff_t offset, + char *addr, unsigned long count); +int __init integrity_read_file(const char *path, char **data); + #define INTEGRITY_KEYRING_EVM 0 #define INTEGRITY_KEYRING_MODULE 1 #define INTEGRITY_KEYRING_IMA 2