diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2018-04-20 14:23:36 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-16 10:08:45 +0200 |
| commit | 5edbd2d8db426d49bc570a3a019720b5e810d951 (patch) | |
| tree | 2a3ed6963df5f913f4cd7a6fee8910b1a0e2bfa0 | |
| parent | 688d5d9189ce0132564be4f4642ae5f4087a3c7c (diff) | |
perf/x86/msr: Fix possible Spectre-v1 indexing in the MSR driver
commit 06ce6e9b6d6c09d4129c6e24a1314a395d816c10 upstream.
> 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 (Intel) <peterz@infradead.org>
Cc: <stable@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/events/msr.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/events/msr.c b/arch/x86/events/msr.c index 4bb3ec69e8ea..be0b1968d60a 100644 --- a/arch/x86/events/msr.c +++ b/arch/x86/events/msr.c @@ -1,4 +1,5 @@ #include <linux/perf_event.h> +#include <linux/nospec.h> #include <asm/intel-family.h> enum perf_msr_id { @@ -136,9 +137,6 @@ static int msr_event_init(struct perf_event *event) 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 || @@ -149,6 +147,11 @@ static int msr_event_init(struct perf_event *event) event->attr.sample_period) /* no sampling */ return -EINVAL; + if (cfg >= PERF_MSR_EVENT_MAX) + return -EINVAL; + + cfg = array_index_nospec((unsigned long)cfg, PERF_MSR_EVENT_MAX); + if (!msr[cfg].attr) return -EINVAL; |