From patchwork Tue Nov 10 18:29:11 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3/5] UBUNTU: SAUCE: AppArmor: Fix cap audit_caching preemption disabling Date: Tue, 10 Nov 2009 08:29:11 -0000 From: John Johansen X-Patchwork-Id: 38067 Message-Id: <1257877753-9448-4-git-send-email-john.johansen@canonical.com> To: kernel-team@lists.ubuntu.com BugLink: http://bugs.launchpad.net/bugs/479102 SRU Justification: Failing to put_cpu_var means that kernel preemption is disabled for the task. This will affect all confined processes that try to audit a capability message (so an process that has capability violation or is in learning mode and would have a capability violation). The auditing code of capabilities, has a simple cache to reduce capability messages flooding the audit logs. Checking and updating the cache disables kernel preemption. One potential exit path does not properly put the per cpu var, thus not reenabling preemption. Signed-off-by: John Johansen Acked-by: Stefan Bader Acked-by: Andy Whitcroft --- ubuntu/apparmor/capability.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/ubuntu/apparmor/capability.c b/ubuntu/apparmor/capability.c index 65b91cf..5bb2eca 100644 --- a/ubuntu/apparmor/capability.c +++ b/ubuntu/apparmor/capability.c @@ -72,6 +72,7 @@ static int aa_audit_caps(struct aa_profile *profile, struct aa_audit_caps *sa) /* Do simple duplicate message elimination */ ent = &get_cpu_var(audit_cache); if (sa->base.task == ent->task && cap_raised(ent->caps, sa->cap)) { + put_cpu_var(audit_cache); if (PROFILE_COMPLAIN(profile)) return 0; return sa->base.error;