lkml.org 
[lkml]   [2022]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.17 017/772] usb: isp1760: Fix out-of-bounds array access
    Date
    From: Linus Walleij <linus.walleij@linaro.org>

    commit 26ae2c942b5702f2e43d36b2a4389cfb7d616b6a upstream.

    Running the driver through kasan gives an interesting splat:

    BUG: KASAN: global-out-of-bounds in isp1760_register+0x180/0x70c
    Read of size 20 at addr f1db2e64 by task swapper/0/1
    (...)
    isp1760_register from isp1760_plat_probe+0x1d8/0x220
    (...)

    This happens because the loop reading the regmap fields for the
    different ISP1760 variants look like this:

    for (i = 0; i < HC_FIELD_MAX; i++) { ... }

    Meaning it expects the arrays to be at least HC_FIELD_MAX - 1 long.

    However the arrays isp1760_hc_reg_fields[], isp1763_hc_reg_fields[],
    isp1763_hc_volatile_ranges[] and isp1763_dc_volatile_ranges[] are
    dynamically sized during compilation.

    Fix this by putting an empty assignment to the [HC_FIELD_MAX]
    and [DC_FIELD_MAX] array member at the end of each array.
    This will make the array one member longer than it needs to be,
    but avoids the risk of overwriting whatever is inside
    [HC_FIELD_MAX - 1] and is simple and intuitive to read. Also
    add comments explaining what is going on.

    Fixes: 1da9e1c06873 ("usb: isp1760: move to regmap for register access")
    Cc: stable@vger.kernel.org
    Cc: Rui Miguel Silva <rui.silva@linaro.org>
    Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
    Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
    Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
    Link: https://lore.kernel.org/r/20220516091424.391209-1-linus.walleij@linaro.org
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/usb/isp1760/isp1760-core.c | 8 ++++++++
    1 file changed, 8 insertions(+)

    --- a/drivers/usb/isp1760/isp1760-core.c
    +++ b/drivers/usb/isp1760/isp1760-core.c
    @@ -251,6 +251,8 @@ static const struct reg_field isp1760_hc
    [HW_DM_PULLDOWN] = REG_FIELD(ISP176x_HC_OTG_CTRL, 2, 2),
    [HW_DP_PULLDOWN] = REG_FIELD(ISP176x_HC_OTG_CTRL, 1, 1),
    [HW_DP_PULLUP] = REG_FIELD(ISP176x_HC_OTG_CTRL, 0, 0),
    + /* Make sure the array is sized properly during compilation */
    + [HC_FIELD_MAX] = {},
    };

    static const struct reg_field isp1763_hc_reg_fields[] = {
    @@ -321,6 +323,8 @@ static const struct reg_field isp1763_hc
    [HW_DM_PULLDOWN_CLEAR] = REG_FIELD(ISP1763_HC_OTG_CTRL_CLEAR, 2, 2),
    [HW_DP_PULLDOWN_CLEAR] = REG_FIELD(ISP1763_HC_OTG_CTRL_CLEAR, 1, 1),
    [HW_DP_PULLUP_CLEAR] = REG_FIELD(ISP1763_HC_OTG_CTRL_CLEAR, 0, 0),
    + /* Make sure the array is sized properly during compilation */
    + [HC_FIELD_MAX] = {},
    };

    static const struct regmap_range isp1763_hc_volatile_ranges[] = {
    @@ -405,6 +409,8 @@ static const struct reg_field isp1761_dc
    [DC_CHIP_ID_HIGH] = REG_FIELD(ISP176x_DC_CHIPID, 16, 31),
    [DC_CHIP_ID_LOW] = REG_FIELD(ISP176x_DC_CHIPID, 0, 15),
    [DC_SCRATCH] = REG_FIELD(ISP176x_DC_SCRATCH, 0, 15),
    + /* Make sure the array is sized properly during compilation */
    + [DC_FIELD_MAX] = {},
    };

    static const struct regmap_range isp1763_dc_volatile_ranges[] = {
    @@ -458,6 +464,8 @@ static const struct reg_field isp1763_dc
    [DC_CHIP_ID_HIGH] = REG_FIELD(ISP1763_DC_CHIPID_HIGH, 0, 15),
    [DC_CHIP_ID_LOW] = REG_FIELD(ISP1763_DC_CHIPID_LOW, 0, 15),
    [DC_SCRATCH] = REG_FIELD(ISP1763_DC_SCRATCH, 0, 15),
    + /* Make sure the array is sized properly during compilation */
    + [DC_FIELD_MAX] = {},
    };

    static const struct regmap_config isp1763_dc_regmap_conf = {

    \
     
     \ /
      Last update: 2022-06-07 22:19    [W:4.090 / U:0.096 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site