linux-kernel - [PATCH] perf/x86/intel/uncore: fix wrong box pointer check

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-next>] [day] [month] [year] [list]

Date:   Thu, 29 Jun 2017 12:09:26 -0700
From:   kan.liang@...el.com
To:     tglx@...utronix.de, mingo@...hat.com
Cc:     linux-kernel@...r.kernel.org, Kan Liang <kan.liang@...el.com>
Subject: [PATCH] perf/x86/intel/uncore: fix wrong box pointer check

From: Kan Liang <kan.liang@...el.com>

Should not init a NULL box. It will cause system crash.
The issue looks like caused by a typo. It is introduced from:

commit fff4b87e594a ("perf/x86/intel/uncore: Make package handling
more robust")

This was not noticed because there is no NULL box. Also, for most
boxes, they are enabled by default. The init code is not critical.

Signed-off-by: Kan Liang <kan.liang@...el.com>
---
 arch/x86/events/intel/uncore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 758c1aa5009d..44ec523287f6 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1170,7 +1170,7 @@ static int uncore_event_cpu_online(unsigned int cpu)
 		pmu = type->pmus;
 		for (i = 0; i < type->num_boxes; i++, pmu++) {
 			box = pmu->boxes[pkg];
-			if (!box && atomic_inc_return(&box->refcnt) == 1)
+			if (box && atomic_inc_return(&box->refcnt) == 1)
 				uncore_box_init(box);
 		}
 	}
-- 
2.11.0