Re: [PATCH] ring-buffer: Fix subbuf_ids memory leak in rb_allocate_cpu_buffer() error path

On Thu, 30 Jul 2026 09:13:08 +0100
Vincent Donnefort <[email protected]> wrote:

> > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> > index 78d3875a47a5..03f6baf6a5f5 100644
> > --- a/kernel/trace/ring_buffer.c
> > +++ b/kernel/trace/ring_buffer.c
> > @@ -2599,6 +2599,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
> >  	return_ptr(cpu_buffer);
> >  
> >   fail_free_reader:
> > +	if (cpu_buffer->remote)
> > +		kfree(cpu_buffer->subbuf_ids);  
> 
> alloc_cpu_buffer() being kzalloc, I suppose here we could just unconditionally
> call kfree(cpu_buffer->subbuf_ids) ?

Agreed. This also removes the coupling between the freeing of subbuf_ids
and it being a remote (in case something else decides to use it).

-- Steve


> 
> >  	free_buffer_page(cpu_buffer->reader_page);
> >  
> >  	return NULL;
> >