From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2373C7EE24 for ; Wed, 3 May 2023 00:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229536AbjECAXz (ORCPT ); Tue, 2 May 2023 20:23:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbjECAXz (ORCPT ); Tue, 2 May 2023 20:23:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F0241997; Tue, 2 May 2023 17:23:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BCF13629E1; Wed, 3 May 2023 00:23:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2433DC433D2; Wed, 3 May 2023 00:23:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1683073433; bh=WX5/T9gGKj7QbyjkiSdD/gogCMpeFq2aRDLi3i4rBh8=; h=Date:To:From:Subject:From; b=F3r+eLhPOaEndm6P3E8lIDdpXTLGTZ2frGjn1O5VC6q57hV55F8qCnE7Doy4N+CYp HZGt+Q3R6jfHEt4CmkJ1WiTZpKTuCxJzBn1k5Nlp+VSFQJtt6KiFMtJ0SLUaxQ13/w 7J7bVZDthQQgb/6QlmkRctKvrAihCKE2dDzyN7+w= Date: Tue, 02 May 2023 17:23:52 -0700 To: mm-commits@vger.kernel.org, zhou.kete@h3c.com, zhao_lei1@hoperun.com, yangpc@wangsu.com, stable@vger.kernel.org, axboe@kernel.dk, zhang.zhengming@h3c.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] relayfs-fix-out-of-bounds-access-in-relay_file_read.patch removed from -mm tree Message-Id: <20230503002353.2433DC433D2@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: relayfs: fix out-of-bounds access in relay_file_read has been removed from the -mm tree. Its filename was relayfs-fix-out-of-bounds-access-in-relay_file_read.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Zhang Zhengming Subject: relayfs: fix out-of-bounds access in relay_file_read Date: Wed, 19 Apr 2023 12:02:03 +0800 There is a crash in relay_file_read, as the var from point to the end of last subbuf. The oops looks something like: pc : __arch_copy_to_user+0x180/0x310 lr : relay_file_read+0x20c/0x2c8 Call trace: __arch_copy_to_user+0x180/0x310 full_proxy_read+0x68/0x98 vfs_read+0xb0/0x1d0 ksys_read+0x6c/0xf0 __arm64_sys_read+0x20/0x28 el0_svc_common.constprop.3+0x84/0x108 do_el0_svc+0x74/0x90 el0_svc+0x1c/0x28 el0_sync_handler+0x88/0xb0 el0_sync+0x148/0x180 We get the condition by analyzing the vmcore: 1). The last produced byte and last consumed byte both at the end of the last subbuf 2). A softirq calls function(e.g __blk_add_trace) to write relay buffer occurs when an program is calling relay_file_read_avail(). relay_file_read relay_file_read_avail relay_file_read_consume(buf, 0, 0); //interrupted by softirq who will write subbuf .... return 1; //read_start point to the end of the last subbuf read_start = relay_file_read_start_pos //avail is equal to subsize avail = relay_file_read_subbuf_avail //from points to an invalid memory address from = buf->start + read_start //system is crashed copy_to_user(buffer, from, avail) Link: https://lkml.kernel.org/r/20230419040203.37676-1-zhang.zhengming@h3c.com Fixes: 8d62fdebdaf9 ("relay file read: start-pos fix") Signed-off-by: Zhang Zhengming Reviewed-by: Zhao Lei Reviewed-by: Zhou Kete Reviewed-by: Pengcheng Yang Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton --- kernel/relay.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/relay.c~relayfs-fix-out-of-bounds-access-in-relay_file_read +++ a/kernel/relay.c @@ -989,7 +989,8 @@ static size_t relay_file_read_start_pos( size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; size_t consumed = buf->subbufs_consumed % n_subbufs; - size_t read_pos = consumed * subbuf_size + buf->bytes_consumed; + size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed) + % (n_subbufs * subbuf_size); read_subbuf = read_pos / subbuf_size; padding = buf->padding[read_subbuf]; _ Patches currently in -mm which might be from zhang.zhengming@h3c.com are