On Wed,  8 Jul 2026 14:32:01 +0100
Vincent Donnefort <[email protected]> wrote:

> If page allocation fails in trace_remote_alloc_buffer(), desc->nr_cpus
> is not yet incremented for the current CPU. As a consequence, on error,
> half-allocated rb_desc will not be freed in trace_remote_free_buffer().
> 
> Include the failing CPU in desc->nr_cpus before going to the error path.
> 

Looks like Sashiko found other issues you may want to address:

  https://sashiko.dev/#/patchset/20260708133201.295072-1-vdonnefort%40google.com

-- Steve

> Fixes: 96e43537af54 ("tracing: Introduce trace remotes")
> Reported-by: Sashiko <[email protected]>
> Signed-off-by: Vincent Donnefort <[email protected]>
> 
> diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c
> index 2a6cc000ec98..62d3d431c309 100644
> --- a/kernel/trace/trace_remote.c
> +++ b/kernel/trace/trace_remote.c
> @@ -1008,8 +1008,10 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc 
> *desc, size_t desc_size,
>  
>               for (id = 0; id < nr_pages; id++) {
>                       rb_desc->page_va[id] = (unsigned 
> long)__get_free_page(GFP_KERNEL);
> -                     if (!rb_desc->page_va[id])
> +                     if (!rb_desc->page_va[id]) {
> +                             desc->nr_cpus++; /* Free this 
> partially-allocated rb_desc */
>                               goto err;
> +                     }
>  
>                       rb_desc->nr_page_va++;
>               }
> 
> base-commit: 8cdeaa50eae8dad34885515f62559ee83e7e8dda


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