[PATCH v2 6/7] ima: Discard files opened with O_PATH

[Roberto Sassu]

From: Roberto Sassu <roberto.sassu at huawei.com>

According to man open.2, files opened with O_PATH are not really opened. The
obtained file descriptor is used to indicate a location in the filesystem
tree and to perform operations that act purely at the file descriptor
level.

Thus, ignore open() syscalls with O_PATH, since IMA cares about file data.

Cc: stable at vger.kernel.org # v2.6.39.x
Fixes: 1abf0c718f15a ("New kind of open files - "location only".")
Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
---
 security/integrity/ima/ima_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 50b37420ea2c..712c3a522e6c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -202,7 +202,8 @@ static void ima_file_free(struct file *file)
 	struct inode *inode = file_inode(file);
 	struct ima_iint_cache *iint;
 
-	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode) ||
+	    (file->f_flags & O_PATH))
 		return;
 
 	iint = ima_iint_find(inode);
@@ -232,7 +233,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	enum hash_algo hash_algo;
 	unsigned int allowed_algos = 0;
 
-	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode) ||
+	    (file->f_flags & O_PATH))
 		return 0;
 
 	/* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
-- 
2.47.0.118.gfd3785337b