bc7b488b1d
While loading the DMC firmware we were double checking the headers made sense, but in no place we checked that we were actually reading memory we were supposed to. This could be wrong in case the firmware file is truncated or malformed. Before this patch: # ls -l /lib/firmware/i915/icl_dmc_ver1_07.bin -rw-r--r-- 1 root root 25716 Feb 1 12:26 icl_dmc_ver1_07.bin # truncate -s 25700 /lib/firmware/i915/icl_dmc_ver1_07.bin # modprobe i915 # dmesg| grep -i dmc [drm:intel_csr_ucode_init [i915]] Loading i915/icl_dmc_ver1_07.bin [drm] Finished loading DMC firmware i915/icl_dmc_ver1_07.bin (v1.7) i.e. it loads random data. Now it fails like below: [drm:intel_csr_ucode_init [i915]] Loading i915/icl_dmc_ver1_07.bin [drm:csr_load_work_fn [i915]] *ERROR* Truncated DMC firmware, rejecting. i915 0000:00:02.0: Failed to load DMC firmware i915/icl_dmc_ver1_07.bin. Disabling runtime power management. i915 0000:00:02.0: DMC firmware homepage: https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/i915 Before reading any part of the firmware file, validate the input first. Fixes: eb805623d8b1 ("drm/i915/skl: Add support to load SKL CSR firmware.") Cc: stable@vger.kernel.org Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190605235535.17791-1-lucas.demarchi@intel.com
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.
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.