lkml.org 
[lkml]   [2020]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 531/717] ACPI: NFIT: Fix input validation of bus-family
    Date
    From: Dan Williams <dan.j.williams@intel.com>

    commit 9a7e3d7f056831a6193d6d737fb7a26dfdceb04b upstream.

    Dan reports that smatch thinks userspace can craft an out-of-bound bus
    family number. However, nd_cmd_clear_to_send() blocks all non-zero
    values of bus-family since only the kernel can initiate these commands.
    However, in the speculation path, family is a user controlled array
    index value so mask it for speculation safety. Also, since the
    nd_cmd_clear_to_send() safety is non-obvious and possibly may change in
    the future include input validation as if userspace could get past the
    nd_cmd_clear_to_send() gatekeeper.

    Link: http://lore.kernel.org/r/20201111113000.GA1237157@mwanda
    Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
    Fixes: 6450ddbd5d8e ("ACPI: NFIT: Define runtime firmware activation commands")
    Cc: <stable@vger.kernel.org>
    Signed-off-by: Dan Williams <dan.j.williams@intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/acpi/nfit/core.c | 6 +++++-
    1 file changed, 5 insertions(+), 1 deletion(-)

    --- a/drivers/acpi/nfit/core.c
    +++ b/drivers/acpi/nfit/core.c
    @@ -5,6 +5,7 @@
    #include <linux/list_sort.h>
    #include <linux/libnvdimm.h>
    #include <linux/module.h>
    +#include <linux/nospec.h>
    #include <linux/mutex.h>
    #include <linux/ndctl.h>
    #include <linux/sysfs.h>
    @@ -478,8 +479,11 @@ int acpi_nfit_ctl(struct nvdimm_bus_desc
    cmd_mask = nd_desc->cmd_mask;
    if (cmd == ND_CMD_CALL && call_pkg->nd_family) {
    family = call_pkg->nd_family;
    - if (!test_bit(family, &nd_desc->bus_family_mask))
    + if (family > NVDIMM_BUS_FAMILY_MAX ||
    + !test_bit(family, &nd_desc->bus_family_mask))
    return -EINVAL;
    + family = array_index_nospec(family,
    + NVDIMM_BUS_FAMILY_MAX + 1);
    dsm_mask = acpi_desc->family_dsm_mask[family];
    guid = to_nfit_bus_uuid(family);
    } else {

    \
     
     \ /
      Last update: 2020-12-28 15:45    [W:4.048 / U:0.568 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site