From 05a085c7c501b7bec772eafb421d19be15b8e7e1 Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Fri, 10 Aug 2018 13:23:15 -0600 Subject: libnvdimm: fix ars_status output length calculation 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(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index c1a65ce31243..de6d3b749c60 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -748,9 +748,9 @@ u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd, * 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; -- cgit v1.2.3