From 1d91ac6213003f525ac34da5e39cbb6612d19deb Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 27 Feb 2014 20:16:47 +0200 Subject: ima: skip memory allocation for empty files Memory allocation is unnecessary for empty files. This patch calculates the hash without memory allocation. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_crypto.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'security/integrity') diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index d257e3631152..1bde8e627766 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -87,16 +87,20 @@ static int ima_calc_file_hash_tfm(struct file *file, if (rc != 0) return rc; - rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!rbuf) { - rc = -ENOMEM; + i_size = i_size_read(file_inode(file)); + + if (i_size == 0) goto out; - } + + rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!rbuf) + return -ENOMEM; + if (!(file->f_mode & FMODE_READ)) { file->f_mode |= FMODE_READ; read = 1; } - i_size = i_size_read(file_inode(file)); + while (offset < i_size) { int rbuf_len; @@ -113,12 +117,12 @@ static int ima_calc_file_hash_tfm(struct file *file, if (rc) break; } - kfree(rbuf); - if (!rc) - rc = crypto_shash_final(&desc.shash, hash->digest); if (read) file->f_mode &= ~FMODE_READ; + kfree(rbuf); out: + if (!rc) + rc = crypto_shash_final(&desc.shash, hash->digest); return rc; } -- cgit v1.2.3