From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 289F31C26 for ; Wed, 23 Nov 2022 09:02:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9892FC433D6; Wed, 23 Nov 2022 09:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669194153; bh=hsF3IExjuTWRbwAY/NmnLhX8WQSEw1tztA4SLhFE8Hs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2VVH9u26dx3onHcT0LuoQaZkqyS3XCVakh6cWo0lhl5Ff8IQBMK29Ts8+KZ5mQ/VK 7fmVhusefOlnvBX+iua22/So0EMxCGAF896FJEHoIfvmUnFpYT5FU5Ppxtq0fSOel9 WWonrQEWVtcXKPnK47dedYmjUsaRAERFXbg1PTxY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniil Tatianin , "Steven Rostedt (Google)" Subject: [PATCH 4.14 56/88] ring_buffer: Do not deactivate non-existant pages Date: Wed, 23 Nov 2022 09:50:53 +0100 Message-Id: <20221123084550.497391207@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084548.535439312@linuxfoundation.org> References: <20221123084548.535439312@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Daniil Tatianin commit 56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd upstream. rb_head_page_deactivate() expects cpu_buffer to contain a valid list of ->pages, so verify that the list is actually present before calling it. Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru Cc: stable@vger.kernel.org Fixes: 77ae365eca895 ("ring-buffer: make lockless") Signed-off-by: Daniil Tatianin Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ring_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1271,9 +1271,9 @@ static void rb_free_cpu_buffer(struct ri free_buffer_page(cpu_buffer->reader_page); - rb_head_page_deactivate(cpu_buffer); - if (head) { + rb_head_page_deactivate(cpu_buffer); + list_for_each_entry_safe(bpage, tmp, head, list) { list_del_init(&bpage->list); free_buffer_page(bpage);