Tomi Valkeinen
064253c1c0
drm: fix use of freed memory in drm_mode_setcrtc
drm_mode_setcrtc() retries modesetting in case one of the functions it calls returns -EDEADLK. connector_set, mode and fb are freed before retrying, but they are not set to NULL. This can cause drm_mode_setcrtc() to use those variables. For example: On the first try __drm_mode_set_config_internal() returns -EDEADLK. connector_set, mode and fb are freed. Next retry starts, and drm_modeset_lock_all_ctx() returns -EDEADLK, and we jump to 'out'. The code will happily try to release all three again. This leads to crashes of different kinds, depending on the sequence the EDEADLKs happen. Fix this by setting the three variables to NULL at the start of the retry loop. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20180917110054.4053-1-tomi.valkeinen@ti.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. 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.
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