Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 57/63] libnvdimm: fix ars_status output length calculation | Date | Fri, 7 Sep 2018 23:10:28 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Vishal Verma <vishal.l.verma@intel.com>
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=<optimized out>, bus_name=<optimized out>) at daxdev-errors.c:332
Cc: <stable@vger.kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Lukasz Dorau <lukasz.dorau@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Fixes: efda1b5d87cb ("acpi, nfit, libnvdimm: fix / harden ars_status output length handling") Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-of-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/nvdimm/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -748,9 +748,9 @@ 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;
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