13e3d94110
drm_gem_fb_init() is passed the fb and never allocates it, so it should be
not the one freeing it. As it is now the second call to kfree() is possible
with the same fb. Coverity reported the following:
*** CID 1492613: Memory - corruptions (USE_AFTER_FREE)
/drivers/gpu/drm/drm_gem_framebuffer_helper.c: 230 in drm_gem_fb_create_with_funcs()
224 fb = kzalloc(sizeof(*fb), GFP_KERNEL);
225 if (!fb)
226 return ERR_PTR(-ENOMEM);
227
228 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
229 if (ret) {
vvv CID 1492613: Memory - corruptions (USE_AFTER_FREE)
vvv Calling "kfree" frees pointer "fb" which has already been freed. [Note: The source code implementation of the function has been overridden by a user model.]
230 kfree(fb);
231 return ERR_PTR(ret);
232 }
233
234 return fb;
235 }
drm_gem_fb_init_with_funcs() calls drm_gem_fb_init()
drm_gem_fb_init() calls kfree(fb)
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1492613 ("Memory - corruptions")
Fixes: f2b816d78a94 ("drm/core: Allow drivers allocate a subclass of struct drm_framebuffer")
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200415172024.24004-1-andrzej.p@collabora.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.