675807dee3
KASAN reports a use-after-free:
BUG: KASAN: use-after-free in dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core]
Call Trace:
...
dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core]
vidtv_bridge_probe+0x7bf/0xa40 [dvb_vidtv_bridge]
platform_probe+0xb6/0x170
...
Allocated by task 1238:
...
dvb_register_device+0x1a7/0xa70 [dvb_core]
dvb_dmxdev_init+0x2af/0x4a0 [dvb_core]
vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge]
...
Freed by task 1238:
dvb_register_device+0x6d2/0xa70 [dvb_core]
dvb_dmxdev_init+0x2af/0x4a0 [dvb_core]
vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge]
...
It is because the error handling in vidtv_bridge_dvb_init() is wrong.
First, vidtv_bridge_dmx(dev)_init() will clean themselves when fail, but
goto fail_dmx(_dev): calls release functions again, which causes
use-after-free.
Also, in fail_fe, fail_tuner_probe and fail_demod_probe, j = i will cause
out-of-bound when i finished its loop (i == NUM_FE). And the loop
releasing is wrong, although now NUM_FE is 1 so it won't cause problem.
Fix this by correctly releasing everything.
Fixes: f90cf6079bf6 ("media: vidtv: add a bridge driver")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
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.