[PATCH] perf powerpc-vpadtl: Fix off-by-one in auxtrace_info minimum size check

[Wang Yan <wangyan01@kylinos.cn>]

min_sz is set to sizeof(u64) * POWERPC_VPADTL_TYPE, but the code reads
auxtrace_info->priv[POWERPC_VPADTL_TYPE], which needs at least
POWERPC_VPADTL_TYPE + 1 elements.  POWERPC_VPADTL_TYPE is the first
enumerator of the priv index enum (0), so min_sz evaluates to 0 and the
check validates only the perf_record_auxtrace_info header itself.  A
PERF_RECORD_AUXTRACE_INFO event carrying a zero-length priv array then
passes the size check, and the subsequent priv[POWERPC_VPADTL_TYPE]
read runs one u64 past the validated region.

This is the same off-by-one fixed for Intel PT by commit c4362d5e1a5e
("perf intel-pt: Fix off-by-one in auxtrace_info minimum size check")
and for Intel BTS by commit b9fb8225951c ("perf intel-bts: Fix off-by-one
in auxtrace_info minimum size check").

Use sizeof(u64) * (POWERPC_VPADTL_TYPE + 1) so the highest accessed
priv index is covered by the minimum-size validation.

Fixes: c4bbd4ec2e50 ("perf powerpc: Process auxtrace events and display in 'perf report -D'")
Cc: stable@vger.kernel.org
Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
---
 tools/perf/util/powerpc-vpadtl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/powerpc-vpadtl.c b/tools/perf/util/powerpc-vpadtl.c
index 710f3093f3f9..c15636eef34b 100644
--- a/tools/perf/util/powerpc-vpadtl.c
+++ b/tools/perf/util/powerpc-vpadtl.c
@@ -683,7 +683,7 @@ int powerpc_vpadtl_process_auxtrace_info(union perf_event *event,
 				  struct perf_session *session)
 {
 	struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
-	size_t min_sz = sizeof(u64) * POWERPC_VPADTL_TYPE;
+	size_t min_sz = sizeof(u64) * (POWERPC_VPADTL_TYPE + 1);
 	struct powerpc_vpadtl *vpa;
 	int err;
 
-- 
2.25.1