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authorPeter Zijlstra <[email protected]>2018-04-20 14:06:29 +0200
committerIngo Molnar <[email protected]>2018-05-05 08:37:28 +0200
commitef9ee4ad38445a30909c48998624861716f2a994 (patch)
tree58c3666c15a10c96fcd0191e2bf906bbc6ed3fba
parent4411ec1d1993e8dbff2898390e3fed280d88e446 (diff)
perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_*
> arch/x86/events/core.c:319 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_event_ids[cache_type]' (local cap) > arch/x86/events/core.c:319 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_event_ids' (local cap) > arch/x86/events/core.c:328 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_extra_regs[cache_type]' (local cap) > arch/x86/events/core.c:328 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_extra_regs' (local cap) Userspace controls @config which contains 3 (byte) fields used for a 3 dimensional array deref. Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r--arch/x86/events/core.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index a6006e7bb729..b1be0ac51ce0 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -304,17 +304,20 @@ set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
config = attr->config;
- cache_type = (config >> 0) & 0xff;
+ cache_type = (config >> 0) & 0xff;
if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
return -EINVAL;
+ cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);
cache_op = (config >> 8) & 0xff;
if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
return -EINVAL;
+ cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);
cache_result = (config >> 16) & 0xff;
if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
return -EINVAL;
+ cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);
val = hw_cache_event_ids[cache_type][cache_op][cache_result];