3.16.60-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <[email protected]> commit ef9ee4ad38445a30909c48998624861716f2a994 upstream. > 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: 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]> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <[email protected]> --- arch/x86/kernel/cpu/perf_event.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -274,17 +274,20 @@ set_ext_hw_attr(struct hw_perf_event *hw 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];
