[Patch v3 1/4] perf/x86: Clamp x86_pmu.lbr_nr to MAX_LBR_ENTRIES

[Dapeng Mi]

Ensure x86_pmu.lbr_nr never exceeds MAX_LBR_ENTRIES to avoid
out-of-bounds access when handling the cached LBR stack.

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
 arch/x86/events/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 4df792b139e0..82f6b66db7e2 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2645,6 +2645,8 @@ static int __init init_hw_perf_events(void)
 	if (!x86_pmu.config_mask)
 		x86_pmu.config_mask = X86_RAW_EVENT_MASK;
 
+	x86_pmu.lbr_nr = min(x86_pmu.lbr_nr, MAX_LBR_ENTRIES);
+
 	perf_events_lapic_init();
 	register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");
 
-- 
2.34.1