On Thu, 2025-03-27 at 11:09 -0500, Frederick Lawler wrote: > 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 <f...@cloudflare.com>
Thanks Frederick! Acked-by: Roberto Sassu <roberto.sa...@huawei.com> Roberto > --- > Changes since v2: > - s/mask & MAY_WRITE/file->f_mode & FMODE_WRITE/ > > Changes since v1: > - Add MAY_WRITE && action check to violation_check to avoid MAY_READ > only situations > --- > 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 9b87556b03a7..bc453f5a7531 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -237,7 +237,9 @@ 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; >
