From: Masami Hiramatsu (Google) <[email protected]>
In rb_allocate_cpu_buffer(), cpu_buffer->subbuf_ids is allocated using
kcalloc() when buffer->remote is non-NULL. If a subsequent page allocation
fails (e.g., ring_buffer_desc_page() returns NULL or rb_allocate_pages()
fails), execution jumps to fail_free_reader.
While __free(kfree) automatically frees the outer cpu_buffer structure
at scope exit, kfree(cpu_buffer) does not recursively free nested heap
pointers such as cpu_buffer->subbuf_ids, resulting in a memory leak.
Fix this by explicitly freeing cpu_buffer->subbuf_ids in the
fail_free_reader error unwinding path when cpu_buffer->remote is set.
Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes")
Assisted-by: Antigravity:gemini-3.6-flash
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
Changes in v2:
- Call kfree(subbuf_ids) unconditionally because it should be NULL
if !remote.
---
kernel/trace/ring_buffer.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 78d3875a47a5..8e2485bb3aa8 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2599,6 +2599,7 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long
nr_pages, int cpu)
return_ptr(cpu_buffer);
fail_free_reader:
+ kfree(cpu_buffer->subbuf_ids);
free_buffer_page(cpu_buffer->reader_page);
return NULL;
