From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org, mingo@kernel.org
Cc: tglx@linutronix.de, dan.j.williams@intel.com,
torvalds@linux-foundation.org,
Dan Carpenter <dan.carpenter@oracle.com>,
"Peter Zijlstra" <peterz@infradead.org>
Subject: [PATCH 4/7] perf,x86/msr: Fix possible Spectre-v1 for msr
Date: Fri, 20 Apr 2018 15:14:11 +0200 [thread overview]
Message-ID: <20180420131631.875020804@infradead.org> (raw)
In-Reply-To: 20180420131407.721875616@infradead.org
[-- Attachment #1: peterz-spectre1-4.patch --]
[-- Type: text/plain, Size: 1016 bytes --]
> arch/x86/events/msr.c:178 msr_event_init() warn: potential spectre issue 'msr' (local cap)
Userspace controls @attr, sanitize cfg (attr->config) before using it
to index an array.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
---
arch/x86/events/msr.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/arch/x86/events/msr.c
+++ b/arch/x86/events/msr.c
@@ -158,9 +158,6 @@ static int msr_event_init(struct perf_ev
if (event->attr.type != event->pmu->type)
return -ENOENT;
- if (cfg >= PERF_MSR_EVENT_MAX)
- return -EINVAL;
-
/* unsupported modes and filters */
if (event->attr.exclude_user ||
event->attr.exclude_kernel ||
@@ -171,6 +168,11 @@ static int msr_event_init(struct perf_ev
event->attr.sample_period) /* no sampling */
return -EINVAL;
+ if (cfg >= PERF_MSR_EVENT_MAX)
+ return -EINVAL;
+
+ cfg = array_index_nospec(cfg, PERF_MSR_EVENT_MAX);
+
if (!msr[cfg].attr)
return -EINVAL;
next prev parent reply other threads:[~2018-04-20 13:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-20 13:14 [PATCH 0/7] Various Spectre-v1 fixes Peter Zijlstra
2018-04-20 13:14 ` [PATCH 1/7] perf: Fix possible Spectre-v1 for aux_pages Peter Zijlstra
2018-04-20 13:14 ` [PATCH 2/7] perf,x86: Fix possible Spectre-v1 for hw_perf_event Peter Zijlstra
2018-04-20 13:14 ` [PATCH 3/7] perf,x86: Fix possible Spectre-v1 for x86_pmu::event_map() Peter Zijlstra
2018-04-20 13:14 ` Peter Zijlstra [this message]
2018-04-20 13:14 ` [PATCH 5/7] perf,x86/cstate: Fix possible Spectre-v1 for pkg_msr Peter Zijlstra
2018-04-20 13:14 ` [PATCH 6/7] sched: Fix possible Spectre-v1 for sched_prio_to_weight[] Peter Zijlstra
2018-04-20 13:14 ` [PATCH 7/7] sched,autogroup: Fix possible Spectre-v1 for sched_prio_to_weight Peter Zijlstra
2018-04-23 1:03 ` [PATCH 0/7] Various Spectre-v1 fixes Michal Hocko
2018-04-23 9:33 ` Peter Zijlstra
2018-04-23 13:50 ` Dan Williams
2018-04-23 16:47 ` Michal Hocko
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