[tip: perf/urgent] perf/x86: Fix potential bad container_of in intel_pmu_hw_config

["tip-bot2 for Ian Rogers" <tip-bot2@linutronix.de>]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     dbde07f06226438cd2cf1179745fa1bec5d8914a
Gitweb:        https://git.kernel.org/tip/dbde07f06226438cd2cf1179745fa1bec5d8914a
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Thu, 12 Mar 2026 12:43:05 -07:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 02 Apr 2026 13:49:16 +02:00

perf/x86: Fix potential bad container_of in intel_pmu_hw_config

Auto counter reload may have a group of events with software events
present within it. The software event PMU isn't the x86_hybrid_pmu and
a container_of operation in intel_pmu_set_acr_caused_constr (via the
hybrid helper) could cause out of bound memory reads. Avoid this by
guarding the call to intel_pmu_set_acr_caused_constr with an
is_x86_event check.

Fixes: ec980e4facef ("perf/x86/intel: Support auto counter reload")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Link: https://patch.msgid.link/20260312194305.1834035-1-irogers@google.com
---
 arch/x86/events/intel/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 36c6821..793335c 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4855,8 +4855,10 @@ static int intel_pmu_hw_config(struct perf_event *event)
 		intel_pmu_set_acr_caused_constr(leader, idx++, cause_mask);
 
 		if (leader->nr_siblings) {
-			for_each_sibling_event(sibling, leader)
-				intel_pmu_set_acr_caused_constr(sibling, idx++, cause_mask);
+			for_each_sibling_event(sibling, leader) {
+				if (is_x86_event(sibling))
+					intel_pmu_set_acr_caused_constr(sibling, idx++, cause_mask);
+			}
 		}
 
 		if (leader != event)