From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49054 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728116AbeIHCNo (ORCPT ); Fri, 7 Sep 2018 22:13:44 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Jiang , Keith Busch , Lukasz Dorau , Dan Williams , Vishal Verma Subject: [PATCH 4.14 80/89] libnvdimm: fix ars_status output length calculation Date: Fri, 7 Sep 2018 23:10:14 +0200 Message-Id: <20180907210901.679442981@linuxfoundation.org> In-Reply-To: <20180907210852.341064285@linuxfoundation.org> References: <20180907210852.341064285@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vishal Verma commit 286e87718103acdf85f4ed323a37e4839a8a7c05 upstream. Commit efda1b5d87cb ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Introduced additional hardening for ambiguity in the ACPI spec for ars_status output sizing. However, it had a couple of cases mixed up. Where it should have been checking for (and returning) "out_field[1] - 4" it was using "out_field[1] - 8" and vice versa. This caused a four byte discrepancy in the buffer size passed on to the command handler, and in some cases, this caused memory corruption like: ./daxdev-errors.sh: line 76: 24104 Aborted (core dumped) ./daxdev-errors $busdev $region malloc(): memory corruption Program received signal SIGABRT, Aborted. [...] #5 0x00007ffff7865a2e in calloc () from /lib64/libc.so.6 #6 0x00007ffff7bc2970 in ndctl_bus_cmd_new_ars_status (ars_cap=ars_cap@entry=0x6153b0) at ars.c:136 #7 0x0000000000401644 in check_ars_status (check=0x7fffffffdeb0, bus=0x604c20) at daxdev-errors.c:144 #8 test_daxdev_clear_error (region_name=, bus_name=) at daxdev-errors.c:332 Cc: Cc: Dave Jiang Cc: Keith Busch Cc: Lukasz Dorau Cc: Dan Williams Fixes: efda1b5d87cb ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Signed-off-by: Vishal Verma Reviewed-by: Keith Busch Signed-of-by: Dave Jiang Signed-off-by: Greg Kroah-Hartman --- drivers/nvdimm/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -808,9 +808,9 @@ u32 nd_cmd_out_size(struct nvdimm *nvdim * overshoots the remainder by 4 bytes, assume it was * including 'status'. */ - if (out_field[1] - 8 == remainder) + if (out_field[1] - 4 == remainder) return remainder; - return out_field[1] - 4; + return out_field[1] - 8; } else if (cmd == ND_CMD_CALL) { struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;