From: Arnaldo Carvalho de Melo Date: Thu, 4 Jun 2026 21:18:05 +0000 (-0300) Subject: perf sched: Fix thread reference leaks in timehist_get_thread() X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=fa20c1f8f4e094abe0169d39fce8181bc26d6dab;p=thirdparty%2Fkernel%2Flinux.git perf sched: Fix thread reference leaks in timehist_get_thread() timehist_get_thread() acquires a thread reference via machine__findnew_thread() and an idle thread reference via get_idle_thread() (which calls thread__get()). Two error paths in the idle_hist block return NULL without releasing these references: - When get_idle_thread() fails, the thread reference leaks. - When thread__priv(idle) returns NULL, both idle and thread leak. Additionally, the idle thread reference acquired on the success path is never released, leaking a reference on every sample when --idle-hist is active. Add thread__put() calls on both error paths and release the idle reference after use on the success path. Fixes: 5d8f17fb5822 ("perf sched timehist: Add -I/--idle-hist option") Reported-by: sashiko-bot Cc: Namhyung Kim Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 4aa7833cae6e3..7bd61028327b3 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -2546,12 +2546,16 @@ static struct thread *timehist_get_thread(struct perf_sched *sched, idle = get_idle_thread(sample->cpu); if (idle == NULL) { pr_err("Failed to get idle thread for cpu %d.\n", sample->cpu); + thread__put(thread); return NULL; } itr = thread__priv(idle); - if (itr == NULL) + if (itr == NULL) { + thread__put(idle); + thread__put(thread); return NULL; + } thread__put(itr->last_thread); itr->last_thread = thread__get(thread); @@ -2559,6 +2563,8 @@ static struct thread *timehist_get_thread(struct perf_sched *sched, /* copy task callchain when entering to idle */ if (perf_sample__intval(sample, "next_pid") == 0) save_idle_callchain(sched, itr, sample); + + thread__put(idle); } }