linux-kernel - [PATCH 2/2] sched/deadline: Don't return invalid cpu in cpudl_maximum

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1496388663-29067-2-git-send-email-byungchul.park@lge.com>
Date:   Fri, 2 Jun 2017 16:31:03 +0900
From:   Byungchul Park <byungchul.park@....com>
To:     <peterz@...radead.org>, <mingo@...nel.org>
CC:     <linux-kernel@...r.kernel.org>, <juri.lelli@...il.com>,
        <rostedt@...dmis.org>, <kernel-team@....com>
Subject: [PATCH 2/2] sched/deadline: Don't return invalid cpu in cpudl_maximum_cpu()

When the heap tree is empty, cp->elements[0].cpu has meaningless value.
We need to consider the case.

Signed-off-by: Byungchul Park <byungchul.park@....com>
---
 kernel/sched/cpudeadline.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index d4a6963..9b314a9 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -110,7 +110,8 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
 
 static inline int cpudl_maximum_cpu(struct cpudl *cp)
 {
-	return cp->elements[0].cpu;
+	int cpu = cp->elements[0].cpu;
+	return cp->elements[cpu].idx == IDX_INVALID ? -1 : cpu;
 }
 
 static inline u64 cpudl_maximum_dl(struct cpudl *cp)
-- 
1.9.1