[PATCH] perf dlfilter: Avoid leak in v0 API test use of resolve_address()

From: Adrian Hunter
Date: Wed Aug 30 2023 - 14:56:25 EST


The introduction of reference counting causes the v0 API
perf_dlfilter_fns.resolve_address() to leak. v2 API introduced
perf_dlfilter_fns.al_cleanup() to prevent that. For the v0 API, avoid the
leak by exiting the addr_location immediately, since the documentation
makes it clear that pointers obtained via perf_dlfilter_fns are not
necessarily valid (dereferenceable) after 'filter_event' and
'filter_event_early' return.

Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-lkp/202308232146.94d82cb4-oliver.sang@xxxxxxxxx
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/dlfilter.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
index e0f822ebb9b9..1dbf27822ee2 100644
--- a/tools/perf/util/dlfilter.c
+++ b/tools/perf/util/dlfilter.c
@@ -187,6 +187,8 @@ static __s32 dlfilter__resolve_address(void *ctx, __u64 address, struct perf_dlf

if (has_priv(d_al_p))
d_al_p->priv = memdup(&al, sizeof(al));
+ else /* Avoid leak for v0 API */
+ addr_location__exit(&al);

return 0;
}
--
2.34.1