From: Frederick Lawler <[email protected]> [ Upstream commit 30d68cb0c37ebe2dc63aa1d46a28b9163e61caa2 ]
On IMA policy update, if a measure rule exists in the policy, IMA_MEASURE is set for ima_policy_flags which makes the violation_check variable always true. Coupled with a no-action on MAY_READ for a FILE_CHECK call, we're always taking the inode_lock(). This becomes a performance problem for extremely heavy read-only workloads. Therefore, prevent this only in the case there's no action to be taken. Signed-off-by: Frederick Lawler <[email protected]> Acked-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- security/integrity/ima/ima_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 98308a2bdef6e..068edb0d79f73 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -235,7 +235,9 @@ static int process_measurement(struct file *file, const struct cred *cred, &allowed_algos); violation_check = ((func == FILE_CHECK || func == MMAP_CHECK || func == MMAP_CHECK_REQPROT) && - (ima_policy_flag & IMA_MEASURE)); + (ima_policy_flag & IMA_MEASURE) && + ((action & IMA_MEASURE) || + (file->f_mode & FMODE_WRITE))); if (!action && !violation_check) return 0; -- 2.39.5
