From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D64A33624D4 for ; Fri, 31 Jul 2026 14:27:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785508035; cv=none; b=qyj4gLTRH2PfJLiD+DUUFrrerzt0OaxgU5pE3NaI+hnw+RJ4jnGjDG0g5hxDsv8lXpi+qsLzDfsv7iY9ka/CKjuzamppNguqKAFfoZWFIXZBpHjJ4R4zfWban1zp1d8Zilu5+KHIyAiT3+W8utGoFJyBCMlrxt6AGaCwEh8zByo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785508035; c=relaxed/simple; bh=q8I8MZWFhjX7euXez6f4j7D6knYR/kG5TGITk/OF2u8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d3HA4psOUHtI9x8GzlqfuBMVB8CroKvfM33duJMUd2dS8t9f+NjteOgIPR9tKdWKs5c+NlB1wo50sKt8YflWX/bq0SD8cn8+sh0l91IYZsmENTH8s7b74TqsiGKlQ5gfXSGfdJ6sRrVVkvEvq/e4TaTD+F+4Qh6ItRwD6DTpsnw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=poh+xbh2; arc=none smtp.client-ip=209.85.221.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="poh+xbh2" Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-47f752b3423so938987f8f.3 for ; Fri, 31 Jul 2026 07:27:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785508032; x=1786112832; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=mP7+gGQhSt3U9gtl+FUITqAwQ5hrW23PUFD5XjA3RsI=; b=poh+xbh2Z4H1LaipAq0tArumok4lZ2JvMg9r+s2SHfikS/s9gY7YaMzy4WRjiSbgdq NZy/YlOzrSyQx7CAF8yDwxXEFk6NTG1N2jsA7glOk6JBNYVQtnASUALuZVtwrdFdBvKT fW4rkcRpOqWx4J4VL0DkbdzGPEuxhqmX4m8KIDinR2uSUgpyQ97VJN4cds2/kZ9TGLx5 CLBOq4jObYFiHoLUriV+MTswTSZNsCll5fsO/QfNmiVErL77ALR2cQU5ropxKMjiiLZx ilTaKabYnKG3saCH4QPgs8SZnAnKeJx+n4WZlmvYYjO6SnTq6vXqsvDe3WJlcO/lugy3 Voig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785508032; x=1786112832; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=mP7+gGQhSt3U9gtl+FUITqAwQ5hrW23PUFD5XjA3RsI=; b=pTjnztehmu+tkVjih7mscvWrG9YnNHk6dsnZMgaia/s7ZViZM8WLPL3xbmEGw/dU00 MZCjkQMQ8Pj+pt2scyB78Kx6Eo9qq866yhgIvRkHX4whltTvDRhMvJ27aAllGgXKAUzz +cbHY8K5ZD8lEUcy7l8B+zX7x7/lVz3jm1TzJhRoho7Otd46u+cePPHXy5o43aLrrC+b mTYRzT0uZFfemEYylnntjUlGbpkO3JqRd5v2GVVlzdjj/1b99/mrn7kQtAlNDfQiXlFD 8G2frKVpJScpXwN3z6SC1PW0oJDQIT3ugNcwjU0x9ffiqgw060+Wxk+IzJ5b98TShe+L iZ0A== X-Forwarded-Encrypted: i=1; AHgh+Ro1Jl/UnZhiXgQvb+IazhHWeVQ+q6RBXwifiweLhhu6PCZGkbJnp4K/xIPkcG+zSrH3WY8CMsvCS9/D57c=@vger.kernel.org X-Gm-Message-State: AOJu0Yxa68pweKeaQY8ehAmpiqXDE84pGXbnTB9xCCZCnrY4B5TPzbzW lkgR0F/wETZZt5F4+ni4o5F9Se3HrVsRyzGrWTV5kBSlurCxuDxPgFX4z6Uox0ur7A== X-Gm-Gg: AR+sD11do+F9Nr8FZu+ICSlxzRw8TLVNE3kjWZEwWjGc+ditcf91HMibHknsYsuQTcI cFo8PlVs5ImctP/Z10Z+zIyzltM1eupW5LcXGF4Y4Vde0UOJ/zKgBoevm3cinosHyotQFyd9HyD ul8gXAd8NNrLLUFV5nZGEdzPYK8U4snH9cMc3jJnyJ3eAet0IjxiXexMzi6qi5J9C+KKB6ru8Zs 7vuXmPzXSJpgXI/HTkJnRtaDVTgCjPFLgnfV6ohG4s2Dg477gVFkCkOI90QizHfbu/BWAl+KGa2 iOHtGrG4GMeXDJbdxeAuUkJdL4rlkO2B3Dnz6Pd1z4rVm+dGGpRawWlA9Xs+G+kC1HPaDKoKgaV nadzEpM4Mfo0cqburccaYdbwQfar294crQYnFZbqz7l8h72T++ZiWsMb3MSwABnaOotNSElz7Uz S9d6IlP47yL03NcsCX+mzNZYPaAFGuaWcFcQKXU8cBd6FdYcxYUNhWAiNndJa0Sc2wK3cZDvs7c dkP0e9ZrgclzoXmGjgRED60HBrMJNSesz9G/w/7kWw= X-Received: by 2002:a05:6000:2308:b0:46e:7f72:b6fe with SMTP id ffacd0b85a97d-47fd2adc960mr5202766f8f.19.1785508031404; Fri, 31 Jul 2026 07:27:11 -0700 (PDT) Received: from google.com (135.91.155.104.bc.googleusercontent.com. [104.155.91.135]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47fd458adc9sm5798669f8f.27.2026.07.31.07.27.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jul 2026 07:27:10 -0700 (PDT) Date: Fri, 31 Jul 2026 15:27:07 +0100 From: Vincent Donnefort To: "Masami Hiramatsu (Google)" Cc: Steven Rostedt , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v2] ring-buffer: Fix subbuf_ids memory leak in rb_allocate_cpu_buffer() error path Message-ID: References: <178550740672.380917.6067449683620196150.stgit@devnote2> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <178550740672.380917.6067449683620196150.stgit@devnote2> On Fri, Jul 31, 2026 at 11:16:46PM +0900, Masami Hiramatsu (Google) wrote: > From: Masami Hiramatsu (Google) > > 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) > --- > 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; > Thanks! Reviewed-by: Vincent Donnefort -- Vincent