I found this bug by looking for places where we do ERR_PTR(0). The
callers for perf_event_alloc() don't expect NULL returns and will oops.
At first it looked like perf_init_event() can return NULL, but that's
actually dead code. I removed it. But if the kcalloc() fails then we
do need to set err = -ENOMEM.
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 13f5b942580b..4c24bc4c8a63 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9177,7 +9177,7 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
static struct pmu *perf_init_event(struct perf_event *event)
{
- struct pmu *pmu = NULL;
+ struct pmu *pmu;
int idx;
int ret;
@@ -9461,9 +9461,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
}
pmu = perf_init_event(event);
- if (!pmu)
- goto err_ns;
- else if (IS_ERR(pmu)) {
+ if (IS_ERR(pmu)) {
err = PTR_ERR(pmu);
goto err_ns;
}
@@ -9476,8 +9474,10 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
sizeof(unsigned long),
GFP_KERNEL);
- if (!event->addr_filters_offs)
+ if (!event->addr_filters_offs) {
+ err = -ENOMEM;
goto err_per_task;
+ }
/* force hw sync on the address filters */
event->addr_filters_gen = 1;
--
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