Hugo Lefeuvre 10db0e22fb staging: pi433: fix race condition in pi433_ioctl
[ Upstream commit 6de4ef65a8 ]

In the PI433_IOC_WR_TX_CFG case in pi433_ioctl, instance->tx_cfg is
modified via

copy_from_user(&instance->tx_cfg, argp, sizeof(struct pi433_tx_cfg)))

without any kind of synchronization. In the case where two threads
would execute this same command concurrently the tx_cfg field might
enter in an inconsistent state.

Additionally: if ioctl(PI433_IOC_WR_TX_CFG) and write() execute
concurrently the tx config might be modified while it is being
copied to the fifo, resulting in potential data corruption.

Fix: Get instance->tx_cfg_lock before modifying tx config in the
PI433_IOC_WR_TX_CFG case in pi433_ioctl.

Also, do not copy data directly from user space to instance->tx_cfg.
Instead use a temporary buffer allowing future checks for correctness
of copied data and simpler code.

Signed-off-by: Hugo Lefeuvre <hle@owl.eu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-03 16:59:16 -07:00
2018-10-03 16:59:13 -07:00
2018-09-26 08:39:28 +02:00
2018-09-29 02:56:03 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%