a574359e2e
In dvb_register_frontend(), dvb_register_device() is possible to fail but its return value is ignored. It will cause use-after-free when module is removed, because in dvb_unregister_frontend() it tries to unregister a not registered device. BUG: KASAN: use-after-free in dvb_remove_device+0x18b/0x1f0 [dvb_core] Read of size 4 at addr ffff88800dff4824 by task rmmod/428 CPU: 3 PID: 428 Comm: rmmod Call Trace: <TASK> ... dvb_remove_device+0x18b/0x1f0 [dvb_core] dvb_unregister_frontend+0x7b/0x130 [dvb_core] vidtv_bridge_remove+0x6e/0x160 [dvb_vidtv_bridge] ... Fix this by catching return value of dvb_register_device(). However the fe->refcount can't be put to zero immediately, because there are still modules calling dvb_frontend_detach() when dvb_register_frontend() fails. Link: https://lore.kernel.org/linux-media/20221108033005.169095-1-chenzhongjin@huawei.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
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.