lkml.org 
[lkml]   [2018]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.16 101/272] ieee802154: ca8210: fix uninitialised data read
    Date
    4.16-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Harry Morris <h.morris@cascoda.com>

    [ Upstream commit 86674a97f5055f4c7f406563408096e8cf9364ff ]

    In ca8210_test_int_user_write() a user can request the transfer of a
    frame with a length field (command.length) that is longer than the
    actual buffer provided (len). In this scenario the driver will copy
    the buffer contents into the uninitialised command[] buffer, then
    transfer <data.length> bytes over the SPI even though only <len> bytes
    had been populated, potentially leaking sensitive kernel memory.

    Also the first 6 bytes of the command buffer must be initialised in case
    a malformed, short packet is written and the uninitialised bytes are
    read in ca8210_test_check_upstream.

    Reported-by: Domen Puncer Kugler <domen.puncer@samsung.com>
    Signed-off-by: Harry Morris <h.morris@cascoda.com>
    Tested-by: Harry Morris <h.morris@cascoda.com>
    Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/net/ieee802154/ca8210.c | 14 +++++++++++---
    1 file changed, 11 insertions(+), 3 deletions(-)

    --- a/drivers/net/ieee802154/ca8210.c
    +++ b/drivers/net/ieee802154/ca8210.c
    @@ -2493,13 +2493,14 @@ static ssize_t ca8210_test_int_user_writ
    struct ca8210_priv *priv = filp->private_data;
    u8 command[CA8210_SPI_BUF_SIZE];

    - if (len > CA8210_SPI_BUF_SIZE) {
    + memset(command, SPI_IDLE, 6);
    + if (len > CA8210_SPI_BUF_SIZE || len < 2) {
    dev_warn(
    &priv->spi->dev,
    - "userspace requested erroneously long write (%zu)\n",
    + "userspace requested erroneous write length (%zu)\n",
    len
    );
    - return -EMSGSIZE;
    + return -EBADE;
    }

    ret = copy_from_user(command, in_buf, len);
    @@ -2511,6 +2512,13 @@ static ssize_t ca8210_test_int_user_writ
    );
    return -EIO;
    }
    + if (len != command[1] + 2) {
    + dev_err(
    + &priv->spi->dev,
    + "write len does not match packet length field\n"
    + );
    + return -EBADE;
    + }

    ret = ca8210_test_check_upstream(command, priv->spi);
    if (ret == 0) {

    \
     
     \ /
      Last update: 2018-05-28 13:56    [W:4.303 / U:0.048 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site