perf: pmu: Fix IS_ERR() vs NULL check bug in perf_pmu__init

[PATCH] perf: pmu: Fix IS_ERR() vs NULL check bug in perf_pmu__init

Posted by Miaoqian Lin 2 months ago

Replace NULL check with IS_ERR() check after calling
hashmap__new() since this function return error pointers (ERR_PTR).
Using NULL check could lead to invalid pointer dereference.

Fixes: 754baf426e09 ("perf pmu: Change aliases from list to hashmap")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 tools/perf/util/pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 5a291f1380ed..da6f05872493 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1176,7 +1176,7 @@ int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name)
 		return -ENOMEM;
 
 	pmu->aliases = hashmap__new(aliases__hash, aliases__equal, /*ctx=*/ NULL);
-	if (!pmu->aliases)
+	if (IS_ERR(pmu->aliases))
 		return -ENOMEM;
 
 	return 0;
-- 
2.25.1

Re: [PATCH] perf: pmu: Fix IS_ERR() vs NULL check bug in perf_pmu__init

Posted by Namhyung Kim 1 month, 2 weeks ago

Hello,

On Tue, Aug 05, 2025 at 10:32:07AM +0400, Miaoqian Lin wrote:
> Replace NULL check with IS_ERR() check after calling
> hashmap__new() since this function return error pointers (ERR_PTR).
> Using NULL check could lead to invalid pointer dereference.
> 
> Fixes: 754baf426e09 ("perf pmu: Change aliases from list to hashmap")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

> ---
>  tools/perf/util/pmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 5a291f1380ed..da6f05872493 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -1176,7 +1176,7 @@ int perf_pmu__init(struct perf_pmu *pmu, __u32 type, const char *name)
>  		return -ENOMEM;
>  
>  	pmu->aliases = hashmap__new(aliases__hash, aliases__equal, /*ctx=*/ NULL);
> -	if (!pmu->aliases)
> +	if (IS_ERR(pmu->aliases))
>  		return -ENOMEM;
>  
>  	return 0;
> -- 
> 2.25.1
>

Re: [PATCH] perf: pmu: Fix IS_ERR() vs NULL check bug in perf_pmu__init

Posted by Ian Rogers 1 month, 2 weeks ago

On Fri, Aug 15, 2025 at 1:35 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> Hello,
>
> On Tue, Aug 05, 2025 at 10:32:07AM +0400, Miaoqian Lin wrote:
> > Replace NULL check with IS_ERR() check after calling
> > hashmap__new() since this function return error pointers (ERR_PTR).
> > Using NULL check could lead to invalid pointer dereference.
> >
> > Fixes: 754baf426e09 ("perf pmu: Change aliases from list to hashmap")
> > Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
>
> Acked-by: Namhyung Kim <namhyung@kernel.org>

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian