From b882fae2d3a832fdcdc194c9f358390b1efca8e7 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 27 Mar 2014 10:54:11 +0200 Subject: [PATCH] ima: prevent unnecessary policy checking ima_rdwr_violation_check is called for every file openning. The function checks the policy even when violation condition is not met. It causes unnecessary policy checking. This patch does policy checking only if violation condition is met. Changelog: - check writecount is greater than zero (Mimi) Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_main.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index dcc98cf542d8..7689c1e21f09 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -81,7 +81,6 @@ static void ima_rdwr_violation_check(struct file *file) { struct inode *inode = file_inode(file); fmode_t mode = file->f_mode; - int must_measure; bool send_tomtou = false, send_writers = false; char *pathbuf = NULL; const char *pathname; @@ -94,16 +93,12 @@ static void ima_rdwr_violation_check(struct file *file) if (mode & FMODE_WRITE) { if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) send_tomtou = true; - goto out; + } else { + if ((atomic_read(&inode->i_writecount) > 0) && + ima_must_measure(inode, MAY_READ, FILE_CHECK)) + send_writers = true; } - must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK); - if (!must_measure) - goto out; - - if (atomic_read(&inode->i_writecount) > 0) - send_writers = true; -out: mutex_unlock(&inode->i_mutex); if (!send_tomtou && !send_writers) -- 2.20.1